Dissertations / Theses: 'Palaeoenvironment'

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Smith, Kate T. "Holocene jökulhlaups, glacier fluctuations and palaeoenvironment, Mýrdalsjökull, South Iceland." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/27426.

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This thesis develops a chronology of jökulhlaup (glacier burst flood) activity from Mýrdalsjökull in southern Iceland. New geornorphological, sedimentological and tephrochronological data has identified 15 flow events during the Holocene. The majority of these were hyperconcentrated flow events originating from, or close to, the northwest area of the ice cap and are associated with subglacial volcanism. One flood originated in the Vei«!»ivötn area and on 3 occasions flooding from Katla may have been accompanied by floods from Eyjafjallajökull. A further two events relate to remobilisation of thick airfall tephra deposits. Silicic pumice found on the sandur and close to the ice margin indicates that the Markarfljót acted as a terrestrial transport route for pumice found along North Atlantic coasts, and was possibly a route for silicic Katla jökulhlaups. Additionally, flood routes and glacial landforms show that Entujökull reached a maximum Holocene extent in the mid-Holocene, extending farther downvalley than during the Little Ice Age. In prehistory, floods were directed to both the south and west of Mýrdalsjökull. Similarly timed jökulhlaups took these paths when floods also flowed from Eyjafjöll into the Markarfljót. This suggests that concurrent routing of floods to the south and west of Mýrdalsjökull is related to synchronous volcanic activity in Katla and Eyjafjallajökull. Since the 10^th Century most Katla floods have been routed to the south east, possibly reflecting changes in intra-caldera eruption sites or subglacial topographic change associated with the Eldgjá eruption in c.935 AD, as suggested by Larsen (2000). The environmental impacts of these floods were significant. Late prehistoric and early historic floods had a major role in shaping the landscape faced by the earliest Norse colonisers of the region. Future flooding could pose a distinct hazard to farmland on the sandur plain downvalley and to popular tourist areas in North Þórsmörk.

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Feurdean, Angelica. "Palaeoenvironment in north-western Romania during the last 15,000 years /." Stockholm : Institutionen för naturgeografi och kvartärgeologi, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-108.

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Sulaiman, Nursufiah Binti. "Late Eocene palaeoenvironment and palaeoclimate of the US Gulf Coast." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7752/.

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This thesis presents new micro palaeontological and geochemical palaenvironmental proxy data through the late Eocene into the earliest Oligocene from a clay-rich succession from the US Gulf Coast. It is based on samples from the Yazoo Clay Formation, recovered in the Mossy Grove Core near Jackson, Mississippi. This represents an apparently continuous section of relatively uniform lithology, clay-rich deposits that host very well preserved assemblages of calcareous nannofossils, foraminifera and organic biomarkers. This thesis makes use of these to generate a detailed calcareous nannofossil taxonomy, high-resolution calcareous nannofossil assemblage data and coccolith-fraction bulk isotope data, as well as pilot planktonic foraminifera abundance and isotope records. It also develops pilot data for organic biomarkers that demonstrate the presence and utility of biomarker proxies for ancient sea surface temperatures within the Yazoo Clay. The results of this project characterize the late Eocene US Gulf Coast as a sub-tropical shelf sea environment that experiences several stages of sea surface cooling and increasing nutrient contents - potentially linked to sea level fall - in the late Eocene and earliest Oligocene. The most important finding of this project is evidence for cooling and major perturbations to the climate-carbon cycle significantly before the onset of the major phases of Antarctic glaciation.

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Davies, Heather Joy. "Sustainable management of the historic environment resource in upland peat : a study from Exmoor." Thesis, University of Plymouth, 2012. http://hdl.handle.net/10026.1/1026.

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UK uplands preserve a rich history of human inhabitation and environmental change through standing monuments, archaeological sites, and within peat deposits. Palaeoenvironmental remains within peat can be used to reconstruct environmental histories throughout the Holocene. Small mires in varied topographic locations can allow detailed local landscape reconstruction, setting archaeological sites in environmental context, or building up a picture of the mosaic of changing landscapes through time. Recent moves towards assessing the ecosystem services provided by different landscapes mean that, to make a case for preserving upland peatlands for the palaeoenvironmental remains they preserve, we must be able to demonstrate their archaeological potential or value. This project investigated methods for identifying the extent of this ‘hidden’ resource, as well for assessing its current condition and historic environment value, through the case study of valley, spring and soligenous mires on Exmoor. The lack of known archaeological or material culture remains from upland peatlands in the UK and on Exmoor means that the project focussed solely on the palaeoenvironmental resource. The methods used combined desk-based survey and spatially-extensive walkover survey to assess the overall extent and condition of the palaeoenvironmental resource in mires across Exmoor. Alongside this, a site-based programme of water-table monitoring and coring was undertaken to look at the effects of recent land management practices on the condition of this resource. The results demonstrated that walkover survey and peat depth probing were necessary to define the spatial extent and depth of mires, and assess mire condition. A standardised key was developed to allow the baseline mire condition survey to be repeated. The site-based study demonstrated the negative impact of water-table draw-down on the condition of palaeoenvironmental remains. However, it also demonstrated that a multiproxy approach is necessary to allow the complex palimpsest of the effects of human impact, climate change, and recent damage to mires, to be disentangled. The results of both levels of survey fed into the development of a flexible heritage valuation system for the palaeoenvironmental resource, which highlighted mires with high-potential for future investigation, whilst indicating mires which will require management intervention to prevent further losses to the resource. The datasets provided by this project will be used to identify palaeoenvironmental sampling locations for future archaeological investigations and allow heritage managers to make active contributions to the selection of sites for mire restoration. It provides a baseline survey against which future mire condition monitoring can be compared and which can be extended to other regions. It also offers a dataset against which to test or ‘ground-truth’ new methods for identifying the extent and condition of peatlands using remote-sensed data.

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Guagnin, Maria. "From savanna to desert : animal engravings in the changing prehistoric environment of the Wadi al-Hayat, Libyan Sahara." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/7814.

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Traditional stylistic classifications have not provided conclusive dates for the rock art of the Sahara, and the imagery can therefore not be placed securely in its cultural or environmental context. This thesis proposes a new methodology in which content and patina of the engravings are used to establish a chronological sequence, against the background of changing palaeoenvironmental conditions. This framework can then be used to explore aspects of the relationship between the rock art and the changing Holocene landscape. The engravings of the Wadi al‐Hayat, which were recently recorded by the Fezzan Rock Art Project, form the basis of this research. A total of 2466 images of animals were individually analysed and entered into a database. The depicted species are shown to reflect the local fauna, and their habitats coincide with the palaeoclimatic conditions of the central Sahara. Additionally, recent geomorphological analyses of the rock surfaces of the Messak provide a chronology for the patina, and show that the formation of each type of patina was dependent on environmental conditions. Through analyses of the animal engravings, categorised according to positively identifiable species and patina types, this thesis demonstrates a direct correlation between the content (i.e. species depicted) and patina of the engravings, and the palaeoenvironment. Both content and patina of the engravings indicate a development from wet savanna to dry savanna, and finally to desert conditions, consistent with the Holocene climatic sequence. This provides a chronological framework for the engravings and places them into a palaeoenvironmental context. The locations of the engravings of each patina group also correspond to the changing lake levels of the al‐Hayat palaeolake identified in previous palaeoenvironmental research projects, which in turn supports the chronology of the engravings. Through spatial analyses, the locations and landscapes preferred by the engravers for the creation of rock art can be identified, whilst the new chronological sequence allows us to explore changes in the cultural conventions that underlie the creation of the engravings. As well as providing a chronological framework and environmental context for the engravings for the Wadi al‐Hayat, the research presented in this thesis therefore has the potential to change our understanding of Saharan rock art.

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Feurdean, Angelica. "Palaeoenvironment in North-Western Romania during the last 15 000 years." Doctoral thesis, Stockholm University, Department of Physical Geography and Quaternary Geology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-108.

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The objectives of this thesis are to establish a chronological framework for environmental changes during the last 15,000 years in northwest Romania, to reconstruct the vegetation development, and to evaluate the underlying processes for forest dynamics. Furthermore, an overview of earlier and ongoing pollenstratigraphic work in Romania is provided.

Sediments from two former crater lakes, Preluca Tiganului and Steregoiu, situated in the Gutaiului Mountains, on the western extremity of the Eastern Carpathians at 730 m and 790 m a.s.l., respectively were obtained and analysed for high-resolution pollen, macrofossils, charcoal, mineral magnetic parameters and organic matter. The chronostratigraphic framework was provided by dense AMS ¹⁴C measurements.

Cold and dry climatic conditions are indicated by the occurrence of open vegetation with shrubs and herbs, and cold lake water prior to 14,700 cal. yr BP. The climatic improvement at the beginning of the Lateglacial interstadial (around 14,700 cal. yr BP) is seen by the development of open forests. These were dominated by Pinus and Betula, but contained also new arriving tree taxa, such as Populus, Alnus and Prunus. The gradual establishment of forests may have led to a stabilization of the soils in the catchment. Between ca. 14,100 and 13,800 cal. yr BP the forest density became reduced to stands of Pinus, Betula, Alnus, Larix and Populus trees and grassland expanded, suggesting colder climatic conditions. Picea arrived as a new taxon at around 13,800 cal. yr BP, and between 13,800 and 12,900 cal. yr BP, the surroundings of the sites were predominantly covered by Picea forest. This forest included Betula, Pinus, Alnus, Larix and Populus and, from 13,200 cal. yr BP onwards also Ulmus. At ca. 12,900 cal. yr BP, the forest became significantly reduced and at 12,600 cal. yr BP, a recurrence of open vegetation with stands of Larix, Pinus, Betula, Salix and Alnus is documented, lasting until 11,500 cal. yr BP. This distinct change in vegetation may by taken as a strong decline in temperature and moisture availability.

At the transition to the Holocene, at ca. 11,500 cal. yr BP, Pinus, Betula and Larix quickly expanded (from small local stands) and formed open forests, probably as a response to warmer and more humid climatic conditions. At 11,250 cal. yr BP Ulmus and Picea expanded and the landscape became completely forested. The rapid increase of Ulmus and Picea after 11,500 cal. yr BP may suggest the existence of small residual populations close to the study sites during the preceding cold interval. Ulmus was the first and most prominent deciduous taxa in the early Holocene in the Gutaiului Mountains. From ca. 10,750 cal. yr BP onwards Quercus, Tilia, Fraxinus and Acer expanded and Corylus arrived. A highly diverse, predominantly deciduous forest with Ulmus, Quercus, Tilia, Fraxinus, Acer, Corylus and Picea developed between 10,700 and 8200 cal. yr BP, which possibly signifies more continental climatic conditions. The development of a Picea-Corylus dominated forest between 8200 and 5700 cal. yr BP is likely connected to a more humid and cooler climate. The establishment of Carpinus and Fagus was dated to 5750 cal. yr BP and 5200 cal. yr BP, respectively. The dominance of Fagus during the late Holocene, from 4000 cal. yr BP onwards, may have been related to cooler and more humid climatic conditions. First signs of human activities are recorded around 2300 cal. yr BP, but only during the last 300 years did local human impact become significant.

The vegetation development recorded in the Gutaiului Mountains during the Lateglacial is very similar to reconstructions based on lowland sites, whereas higher elevation sites seem not to have always experienced visible vegetation changes. The time of tree arrival and expansion during the past 11,500 cal. yr BP seems to have occurred almost synchronously across Romania. The composition of the forests during the Holocene in the Gutaiului Mountains is consistent with that reconstructed at mid-elevation sites, but differs from the forest composition at higher elevations. Important differences between the Gutaiului Mountains and other studied sites in Romania are a low representation of Carpinus and a late and weak human impact.

The available data sets for Romania give evidence for the presence of coniferous and cold-tolerant deciduous trees before 14,700 cal. yr BP. Glacial refugia for Ulmus may have occurred in different parts of Romania, whereas the existence of Quercus, Tilia, Corylus and Fraxinus has not been corroborated.

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Cronin, Kate. "Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal." Bachelor's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/14119.

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The Succulent Karoo is recognised as an important biodiversity hotspot and many of the key plant lineages that characterise the biome are thought to have originated during the Pleistocene epoch. However, due to the paucity of palaeobiological proxy data available for the Succulent Karoo, relatively little is known about its environmental history and how an important core of this region, Namaqualand and its subregion the Richtersveld, may have responded to Pleistocene changes. Recent excavations at Spitzkloof Rockshelter A in the Richtersveld have provided a rare source of palaeoenvironmental data in the form of fossil wood charcoal assemblages that span a sequence from the last glacial maximum (LGM) to ~14 500 yrs BP. The present study analysed the fossil charcoal deposits from the rockshelter in order to reconstruct woody species assemblage patterns as a proxy for late Pleistocene palaeoclimate. Identification of the fossil charcoal specimens was achieved by anatomical comparison with transverse section photomicrographs of identified reference specimens of woody taxa currently growing at the site. Patterns in the charcoal data set were sought by assessing the changes in woody species assemblages over time. An assessment of the environmental correlates of the contemporary distributions of taxa found in the archaeological sequence provided the basis for palaeoenvironmental reconstruction. Based on the current generalisation for glacial climates in the winter rainfall zone (WRZ), it was hypothesised that the study region experienced an increase in rainfall at the LGM, and a steady aridification towards the terminal Pleistocene. However, Spitzkloof's charcoal records provide little evidence to suggest that the LGM supported a more mesic vegetation community than more recent time-periods. Instead, results suggest that the region experienced fairly limited climatic change as there is compelling evidence for the persistence of Succulent Karoo elements â€“ namely Stoeberia arborea, Hermannia disermifolia and Lycium spp. - throughout the late Pleistocene. The localised appearance at the terminal Pleistocene (~14 ka) of all of the most abundant taxa at the site today is interpreted as a consequence of terminal Pleistocene changes in sea-level and CO2 concentration within a persistent context of minimal climatic change. These results have important implications for the applicability of a generalised WRZ model of climate change to the Succulent Karoo and for hypothetical predictions of future climate change impacts in the biome.

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Walker, Thomas M. "Shifting sand : the palaeoenvironment and archaeology of blown sand in Cornwall." Thesis, University of Reading, 2014. http://centaur.reading.ac.uk/78304/.

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Coastal sand dunes are common in Britain, especially along western Atlantic coasts, and archaeological sites are well preserved under blown sand. One of the questions is how Holocene palaeoclimate variation influences patterns of settlement establishment and abandonment. Few studies of coastal sites have included palaeoenvironmental evidence, and even fewer include securely dated stratigraphy. This study uses a multi proxy approach to investigate two main and five minor coastal sites in Cornwall, with molluscs analyses being the principal analytical method. Chronology is established by radiocarbon dating and optically stimulated luminescence so that episodic human activity can be related to periods of sand blow and instability. Evidence is sought concerning the history of mineral mining in the Red River catchment area. Twenty three cores and a test pit were examined along a transect at the multi period site at Gwithian on the north Cornish coast. Mollusc columns were obtained at Strap Rocks near the main Gwithian site, and from five trenches excavated at the early medieval site of Gunwalloe on the Lizard peninsula. The study establishes that initial sand deposition was about 3000 BC, with further marked periods of sand blow in the early and late Bronze Age, the Iron Age and the mid-medieval period. Some, but not all, sand blow correlates with periods of settlement occupation and abandonment, and with known palaeoclimate episodes such as the Little Ice Age. Difficulty in establishing periods of sand conflation and deflation and how this may lead to errors in chronology are discussed. There is weak evidence for mining activity in the Bronze Age, but strong evidence from c 1050 AD. The chronology of mollusc extinctions and introductions is refmed, e.g. Xerocrassa geyeri did not become extinct until the end of the early Bronze Age and Cochlicella acuta was present from the late Neolithic, about 2400 BC.

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Hanif, Muhammad. "Stratigraphy and Palaeoenvironment of the Paleocene/Eocene boundary interval in the Indus Basin, Pakistan." Thesis, University of Plymouth, 2011. http://hdl.handle.net/10026.1/865.

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Marine sedimentary sections across the Paleocene/Eocene (P/E) boundary interval are preserved in the Patala Formation (Upper Indus Basin) and Dungan Formation (Lower Indus Basin), Pakistan. The P/E interval of the Patala Formation is composed of limestone and shale inter-beds indicating deposition on a carbonate platform. The analysis of larger foraminifera across the P/E interval from the Patala Formation (Kala Chitta Ranges), allows the recognition of the Larger Foraminiferal Turnover (LFT). The Larger Foraminiferal Turnover (LFT) observed in the Patala Formation is associated with the PETM (Paleocene Eocene Thermal Maximum) global climatic event and allows the recognition of the P/E boundary in shallow water carbonates of the Indus Basin. This turnover is already reported from other Tethyan sections and from the Salt Range (Upper Indus Basin), Pakistan. The recognition of the LFT allows the inter-basinal and intra-basinal correlation of the P/E interval of the shallow carbonates of the Indus Basin, Pakistan. The available literature on the Paleocene-Eocene Patala and Dungan formations is used to review the planktonic foraminiferal biostratigraphy of the P/E interval. The planktonic foraminiferal zones in the P/E interval of the Indus Basin are identified and reviewed in the light of new international zonations. The planktonic foraminiferal content of the Dungan Formation allows its correlation with the Laki Formation of Rajesthan (India). Four dinoflagellate zones in the P/E interval of the Rakhi Nala section (Lower Indus Basin) are identified and correlated with international and regional zonations. The quantitative analysis of the dinoflagellate cyst assemblages together with geochemical data (i.e., carbon isotopes (organic only), C/N ratio, TOC, carbonate content) is used to reconstruct the palaeoenivronment across the P/E interval. The dinocyst assemblages in general, and the abundance of Apectodinium spp. in particular, indicate the warmer surface water conditions of the global PETM event. The dinocyst assemblages allow the local correlation of the Dungan Formation (part) of the Sulaiman Range with the Patala Formation (part) of the Upper Indus Basin and global correlation of the Zone Pak-DV with the Apectodinium acme Zone of the Northern and Southern hemispheres. The carbon isotopic excursion (CIE) associated with PETM is now globally used to identify the P/E boundary. The CIE in total organic carbon (i.e., δ13CTOC = -28.9‰) and total fine fraction organics (i.e., δ13CFF= 26.4‰) from the Indus Basin is reported for the first time. This CIE record from the Indus Basin is compared with other Tethyan sections from Egypt and Uzbekistan and is also compared with the global sections from USA (Northern hemisphere) and from New Zealand (Southern hemisphere).

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Bennett, R. M. "The palaeoenvironment and diagenesis of the Upper Lias Cephalopod Bed in S.E. Somerset." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379602.

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Burgess, Catherine E. "Palaeoclimate and palaeoenvironment of the middle Eocene southern Pacific : insights from New Zealand." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54756/.

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The Hampden Section of South Island, New Zealand, is used to generate a multiproxy record of middle Eocene palaeoclimate. The Hampden Formation is a calcareous clay-rich siltstone deposited in a shelf edge environment, containing exceptionally well-preserved micro- and nannofossils. A range of sedimentary, geochemical and fossil assemblage records from this formation are combined to provide new insights into middle Eocene climate in the southern Pacific Ocean. A palaeoclimate record generated through the formation spans the period from -42.1 to -39.3 Ma and shows clear cooling in ocean mixed-layer temperatures from -18 C to -14 C, with long period cyclicity (likely -405 k.y.) superimposed. This cooling trend is punctuated by a transient warm excursion of - 2.5 C lasting -450 k.y. that may represent the Middle Eocene Climatic Optimum. There is a brief influx of the tropical planktonic foraminifer Hantkenina australis during this time and the excursion is also marked by a substantial drop in the sand fraction of the sediment, indicating that the warm interval had a significant impact on the terrestrial realm. The water temperatures produced from this record are warmer than those previously estimated for similar latitudes, likely due to the excellent preservation of the microfossils reducing the effect of diagenesis on their geochemistry. These temperatures suggest that during the middle Eocene, the site lay in the path of a warm southward flowing current rather than a cold Antarctic gyre. They also support the hypothesis that the global latitudinal temperature gradient was reduced during the middle Eocene. A shorter high-resolution record of climate was also obtained. This shows -18 k.y. cyclicity in a range of palaeoclimatic and palaeonvironmental proxies that is considered to have been orbitally forced. The Mg/Ca derived bottom water temperatures range from -11 to 13 C and the TEXg6 derived surface water temperatures from -22.5 to 24 C through these cycles. The combination of 8 O and Mg/Ca in foraminiferal carbonates indicates that there was little or no ice present globally. Despite the lack of ice available to amplify the cycles they had a major and complex effect on both the marine and terrestrial environments.

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Cole, James M. "The palynology, palynofacies and palaeoenvironment of the Early Cretaceous Weald Clay of Southeast England." Thesis, London Metropolitan University, 1987. http://repository.londonmet.ac.uk/2941/.

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Brown, Fiona S. J. "Late Holocene environmental change at Castelporziano." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6752.

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The Mediterranean has long been recognised as an area that is particularly sensitive to climate change. It is also an area that has been impacted by human activity for millennia. Disentangling climatic and anthropogenic influences on the history of vegetation change in the Mediterranean remains an important challenge. As a contribution to this ongoing debate, this thesis explores the late Holocene environment of part of the coast in Central Italy using a multiproxy approach to investigate the archives of change preserved in dune slack deposits. Distinguishing between natural and anthropogenic signals presents a real challenge in most environmental reconstruction work; however, due to the extensive archaeological research carried out at Castelporziano, it is possible to examine human-environmental interactions in some detail. In order to understand these interactions part of the thesis examines how management has affected recent environmental changes and the current vegetation and whether there is a legacy of Roman landuse at the Castelporziano estate. The key findings of the thesis showed that dune slacks are suitable for palaeoenvironmental reconstruction with proxies such as plant macrofossils, ostracods, molluscs and bryozoans statoblasts. However, the pH and seasonality of the slacks meant proxies such as pollen were badly preserved or absent, and diatoms did not preserve due to the high levels of carbonate on site. Overall the results show the impact of the Romans on site in terms of localised eutrophication and increased fires, but with abandonment, came the formation of wet woodlands.

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Lim, Jesmine. "Characterisation of the prokaryotic community of Lake Suigetsu, Japan : towards a novel palaeoenvironment research biomarker." Thesis, Northumbria University, 2014. http://nrl.northumbria.ac.uk/27272/.

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Sediment cores from Lake Suigetsu, Japan are recognised as a key record of past climate reconstruction because of the finely laminated sediments that provide precise event stratigraphy. Here, we study the relationship between the microbial communities in the lake sediments of Lake Suigetsu during validated episodes of environmental change. We use fossil DNA from the lake sediment and utilising the PCR-DGGE technique, we detected the presence of several taxa. Among the investigated sediment cores, the Acidobacteria community was found to be the most abundant while the Actinobacteria community was the least. The results showed that the overall bacterial community structure and their diversity were significantly affected by sediment depths, rather than the availability of nutrient (i.e. TOC and TN). The first event was the introduction of saline water in Lake Suigetsu. Historical records have described this event occurring during 1664 AD, which equates to the sediment depth of approximately 81.64 cm. A metagenomics study based on selected sediment depths has exhibited a shift in the bacterial taxa, consistent with the transition of lake salinity from freshwater to brackish. Bacillaceae and Clostridiaceae were found to be more predominant in the brackish sediments relative to the freshwater sediments. Evidence of the seawater incursion was found in the sediment depths between 82.16 and 83.16 cm. The second event was a climate event dated back to the Late Quaternary period. The results presented here show that bacterial diversity and species richness become increased when climate changed from a cold to warmer conditions. The metagenomics analysis on the sediment deposits has demonstrated distinctive differentiations in bacterial taxa during the climate transition from the colder to warmer episodes. This observation could be related to the rapid adaptation/tolerance of bacteria to environmental changes, or simply the effect of depth. Although the temperature-dependent δ15N isotope can be strongly correlated to the bacterial communities, the weak selectivity of the δ15N isotope could result in false correlation between the δ15N isotope and the diversity of the bacterial communities. The application of molecular and culture-dependent techniques was used to characterise bacterial diversity in the sedimentary records of Lake Suigetsu. The culture-based techniques showed a better representation of high GC Actinobacteria while molecular techniques revealed a better profile of Gram negative bacteria. Furthermore, based on a polyphasic approach, several putatively new species have been identified, notably Actinobacteria strains that belong to the genera Dermacoccus, Dietzia, Leifsonia and Rhodococcus. Among the tested strains, a novel Rhodococcus isolate that was recovered from the freshwater sediment, merits recognition of new species status and the name Rhodococcus meromictica sp. nov is proposed.

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Nedin, Christopher. "The palaeontology and palaeoenvironment of the Early Cambrian Emu Bay Shale, Kangaroo Island, South Australia /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phn371.pdf.

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Tsujikawa, Hiroshi. "The Late Miocene Large Mammal Fauna and Palaeoenvironment in the Samburu Hills Area, Northern Kenya." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/149118.

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Meijaard, Erik, and emeijaard@tnc org. "Solving Mammalian Riddles." The Australian National University. Faculty of Arts, 2004. http://thesis.anu.edu.au./public/adt-ANU20050924.221423.

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Since the mid 19th century, the biogeography of island South-East Asia has been the subject of much study. Early researchers explained many of the species distribution patterns by the rise and fall of sea levels and land. This and the work of other researchers culminated in a theory that emphasized the role of Pleistocene sea level low stands in species evolution. With the advent of newly developed molecular techniques, however, it became clear that many species divergence events had taken place before the Pleistocene and a biogeographical theory focusing on Pleistocene sea level changes was inadequate. In this research, I have developed a new biogeographic model that explains present-day distribution patterns and evolutionary relationships between species. I use this new model to explain 10 ‘mammalian riddles’, i.e. evolutionary or distribution patterns in selected mammal species groups that could not be explained with the existing theories. I developed the new model by analyzing the geological literature for this region, and by mapping palaeogeographical and palaeoenvironmental changes for the last 20 million years. In addition I compiled information on the palaeontological record for the region and on divergence times between taxa using a molecular clock assumption. These phylogenetic data were compared with the palaeomaps to assess whether particular divergence events could be correlated with certain palaeogeographical or palaeoenvironmental changes. The combination of these two information sources has resulted in a much-improved understanding of mammalian evolution in island SE Asia. Using this model it is now possible to relate important palaeoenvironmental events, such as the Late Miocene cooling, an Early–Middle Pliocene highstand, or the emergence and submergence of a land bridge between the Malay Peninsula and Java to evolutionary changes in species. I test the accuracy of the new model by analysing the relationships within several mammal groups using craniometric and molecular analysis. The observed relationships and deduced timing of divergence between taxa could in many cases be explained by the model, which indicates that it is relatively accurate. In addition, with the new model I have been able to find solutions to most mammalian riddles, although these results require further testing. Overall, I therefore believe I have made a significant contribution to the biogeographical understanding of island SE Asia.

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Jha, Gopesh. "Assessing the impact of 74ka Toba Super eruption on palaeovegetation of Late Pleistocene South Asia using sedimentary organic biomarkers." Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/31788.

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A erupção de ~74ka Toba é considerada o maior evento vulcânico explosivo dos últimos 23 milhões de anos, com um Índice de Explosividade Volcânica (VEI) de 8,8. Pensa-se que tenha causado um caos global, levando a um arrefecimento global drástico e a um estrangulamento populacional. Muitos registos climáticos globais e estudos de simulação mostraram que ~74ka erupção de Toba teve um impacto severo no hemisfério norte e pode ter afectado também zonas hiper-áridas do hemisfério sul. No entanto, é difícil dizer a manifestação do impacto de Toba no ambiente terrestre local e regional devido à falta de registos ambientais terrestres bem actualizados. A investigação actual fornece uma imagem holística do cenário paleo-ambiental de duas zonas biogeográficas diversas (isto é, planície costeira e inter-montano) que estão directamente associadas ao jovem Toba tufo (YTT). A investigação multi-proxy destes locais levou a seguir inferências: 1) O ambiente local de Tejpor e Jwalapuram já estava inclinado para condições mais secas antes do evento de Toba, sugerindo sinais de evento global GI-20S; 2) Jwalapuram mostra o impacto imediato da erupção de YTT em termos de ambiente húmido e seco altamente instável e oscilante, a queda de cinzas sufocou o sistema fluvial e causou também um certo grau de desflorestação; 3) Tejpor mostra o impacto a longo prazo do YTT, o ambiente local parece ter-se tornado mais seco embora a rotação climática não seja tão severa. A investigação actual sugere que Toba tem um impacto notável que varia no tempo (duração), bem como no espaço. No entanto, é altamente improvável que tenha desencadeado um evento de nível de extinção, uma vez que ambos mostram o sinal de um rápido ressurgimento; Assessing the impact of 74ka Toba Super eruption on palaeovegetation of Late Pleistocene South Asia using sedimentary organic biomarkers - ABSTRACT: The ~74ka Toba eruption is considered the largest explosive volcanic event of the last 23 million years, with a Volcanic Explosivity Index (VEI) of 8.8. It thought to have caused global havoc, leading to drastic global cooling and population bottleneck. Many global climatic records and simulation studies have shown that ~74ka Toba eruption had severe impact on northern hemisphere and may have affected hyper-arid zones of southern hemisphere as well. However, it is hard to tell the manifestation of Toba impact on local and regional terrestrial environment due to lack of well-dated terrestrial environmental record. Current research provides holistic picture of paleoenvironmental setting of two diverse bio-geographical zones (i.e., coastal plain and inter-montane) that are directly associated with young Toba tuff (YTT). Multi-proxy investigation of these sites led to following inferences: 1) Local environment of Tejpor and Jwalapuram was already inclined towards drier conditions prior to Toba event, suggesting sign of global GI-20S event; 2) Jwalapuram shows immediate impact of YTT eruption in terms of highly unstable and oscillating wet-dry environment, ashfall choked the riverine system and caused certain degree of deforestation as well; 3) Tejpor shows the long-term impact of YTT, local environment seems to have become drier although climatic turnover is not that severe. Current investigation suggest that Toba does have remarkable impact that varies in time (duration) as well as space. However, it is highly unlikely that it would have triggered extinction level event, as both shows the sign of rapid resurgence.

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Brownsell, Wendy Joan. "Middle Pleistocene till lithostratigraphy in south Bedfordshire and the Hitchin Gap." Thesis, University of Hertfordshire, 2009. http://hdl.handle.net/2299/3762.

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A revised lithostratigraphy and glacial history of north Hertfordshire and south Bedfordshire is based upon detailed textural data in the clay to fine gravel fraction, carbonate content, small clast lithological data and macrofabrics, derived from laboratory and field analyses of tills from 30 sites. These include four deep boreholes sunk within the Hitchin Gap. A range of statistical procedures was used, including multivariate analysis of the petrographic properties, enabling the identification of tills from two separate incursions into the Gap. A further till-type was identified in south Bedfordshire indicating an ice advance from the northwest/NNW extending at least as far east as Milton Bryan. Statistical comparison with tills in the neighbouring Vale of St. Albans suggested the presence of the Ware Member till within the Gap. Two hypotheses are suggested to explain variations in lithological content of tills north of the Chalk scarp. The first envisages ice entering the study area along the different trajectories suggested by Fish and Whiteman (2001). During the early part of the glaciation, ice reaching the west of the study area would approach from the north, crossing a shorter distance over Chalk bedrock and collecting less chalk and flint than ice moving into the eastern part of the study area. The second hypothesis invokes an incursion of ice from a northwest - NNW direction into the west of the study area, depositing a chalk-free till. This is subsequently assimilated by ice from the northeast, resulting in the final deposition of a homogeneous mixture of debris from the two advances, with a lower chalk content than tills found to the east. The outcome of either of these scenarios is a till with a low acid-soluble content and low flint/quartz ratio in the west of the study area, as found during this work. Within the Hitchin Gap, a lobe of ice, probably an early part of the northeasterly advance, deposited a lower till. This is considered to be earlier than the Ware Member till and has more variable lithological characteristics and a finer matrix that the higher tills. The latter are mainly melt-out, flow or slumped tills with occasional instances of lodgement and deformation. They represent in situ wasting of dead ice within the Gap. Surface tills in the Gap form a continuum with tills to the north and comprise mainly deformation tills, deposited by the final northeasterly re-advance of ice responsible for widespread coverage of the region, with the exception of the Chiltern Hills southwest of Hitchin. No evidence is found of more than one lithostratigraphic unit of till outside the Hitchin Gap.

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Job, Thomas Anthony. "A systemic investigation of coastal acid sulfate soil acidification in the River Murray Estuary, South Australia." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23474.

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Extensive coastal acid sulfate soil (CASS) oxidation was observed in the River Murray Estuary (RME), South Australia, during an extreme drought (the Millennium Drought, 1996–2010). CASS oxidation causes significant surface water and porewater acidity, and the mobilisation of toxicants, negatively impacting proximal ecosystems and infrastructure. In this thesis I argue that the Millennium Drought acidification event provides a test case globally for how meteorological drought triggers extreme CASS oxidation, and how other variables can exacerbate the issue. I therefore present a systemic investigation of CASS acidification within the RME and identify the boundary conditions and exogenous variables that control acidification risk. Elements mobilised from oxidised CASS (Fe, Mn, Al, V, Cr, Co, Ni, Cu, Zn, Cd, Pb, and REE) are accumulating in the sediments of the RME, and spatial patterns of enrichment and REE fractionation can be used as environmental tracers of acidic drainage. Transport and accumulation of these elements is controlled by hydrodynamic and geomorphic processes in the estuary. Multiple depositional regimes apparent in the sediment record show that hydrodynamic and geomorphic processes have, however, changed during the history of the RME in response to sea-level and anthropogenic impacts, impacting the formation of CASS and the likelihood of extreme acidification within the system. Adopting a systems approach, it is apparent that the extremity of the Millennium Drought acidification event was intensified by factors other than drought, and that the triggering of extreme CASS acidification often exhibits a non-linear relationship to boundary condition changes, meaning negative impacts can be sudden and disastrous. Wave-dominated estuaries are particularly vulnerable systems, and changes predicted for an anthropogenically heated future will likely shift estuarine systems closer to thresholds where severe acidification can be expected.

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Robbins, Demian J. C. "Ichnology and palaeoenvironment of the Lower Triassic Montney Formation, Kaybob and Kaybob South fields area, west-central Alberta." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0019/MQ47088.pdf.

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22

Metcalf, Sara J. "The palaeoenvironment and palaeoecology of a Middle Jurassic vertebrate-bearing fen-type paleosol in a coastal carbonate regime." Thesis, University of Bristol, 1995. http://hdl.handle.net/1983/955beb87-8c25-4857-ac91-c3451390ff62.

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23

Dendievel, André-Marie. "Paléoenvironnements holocènes du plateau du Béage (massif du Mézenc, Massif Central, France). Les variations climatiques et les activités anthropiques révélées par l'étude des macro-restes dans les sédiments tourbeux et la gyttja." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSES004/document.

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Cette thèse propose de reconstituer l'histoire environnementale holocène du plateau du Béage en Ardèche (massif duMézenc, Massif Central, France). Ce travail repose sur l'étude des sédiments issus des tourbières de La Narce du Béage et de Pialeloup, mais aussi du marais de Pré-du-Bois et des séquences de la moyenne vallée du Gage. Notre approche vise (1) à caractériser le contenu paléoécologique des sédiments (macro-restes et palynologie), (2) à appréhender les évolutions du bassin versant via une analyse multi-proxies (susceptibilité magnétique, granulométrie,taux de matière organique, géochimie) et (3) à confronter ces éléments aux données locales et régionales disponibles.Durant !'Holocène ancien et moyen, des fluctuations locales d'humidité paraissent concomitantes de changements climatiques majeurs dans l'hémisphère nord (épisodes humides: 10400-10000, 9600-9100, 7900-7400, 6400-6000,5400-5000 cal. BP; secs: 10900-10500, 9900-9600 cal. BP; contrasté: 8500-8150 cal. BP). Cette analyse montre des impacts agro-pastoraux entre 6900 et 6450 cal. BP (Néolithique ancien), entre 5700 et 5200cal. BP (Néolithique moyen 2/récent) puis vers 4800 - 4100 cal. BP (Néolithique final). La pression anthropique s'intensifie entre 2400 et 1250 cal. BP (IVème s. av. J.-C.-Vlème s. apr. J.-C.). Le développement agricole médiéval s'opère à partir de 1050 cal. BP (Xème s.) : culture du seigle, cheptel ovin et bovin, productions de noix et de châtaignes à partir des XIIIème et XIVème s. L'érosion des versants semble aussi stimulée par la péjoration du Petit Âge Glaciaire (Xlllème-XVIIIème s.).Aux XIXème et XXème siècles, les activités d'élevage bovin perdurent mais la céréaliculture finit par disparaître
This PhD thesis has resulted in the reconstruction of the holocene environmental history of the Béage plateau in Ardèche (massif du Mézenc, Massif Central, France). It focussed on the study of organic sediments from the La Narce du Béage and Pialeloup peatlands. Two complementary sites were also considered: the Pré-du-Bois swamp and the alluvial stratigraphies from the middle Gage valley. Our approach aimed (1) to perform a palaeoecological study of these sites (macrofossils and palynology); (2) to better understand watershed evolution thanks to multi-proxies analyses (magnetic susceptibility, grain size, organic matter content, geochemistry); (3) to compare these results with other local to regional data. During the Barly and the Middle Holocene, local humidity variations occuned concurrently with rapid climate changes(RCCs) recorded in the Northern Hemisphere (dry episodes: 10,900-10,500; 9,900-9,600; moist: 10,400-10,000;9,600-9,100; 7,900-7,400; 6,400-6,000 and 5,400-5,000 cal. BP; contrasted: 8,500-8,150 cal. BP). This study also allowed to identify agro-pastoral impacts around 6,900-6,450 cal. BP (Barly Neolithic), around 5, 700-5,000 cal. BP (Middle to Recent Neolithic) and close to 4,800-4,100 cal. BP (Final Neolithic). Anthropogenic impact got stronger between 2,400 and 1,250 cal. BP (IV'h century BC-Vlth century AD). A new stage of landscape management was recorded after 1,050 cal. BP (Xth century AD), involving rye cultivation, extensive livestock grazing(sheep and cattle) and fruit tree farming (walnut and chestnut: XIIIth-XIV'h centuries). Severe soil erosion occurred, alsodriven by the Little Ice Age deterioration (from the XIIlth to the XVth century AD). Finally, during the X!Xth and theXXth centuries cattle grazing remained strong, but cultivation ended due to demographic exodus during the xxth century

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Kourela, Genofeva Eva. "Stratigraphic and palaeoenvironmental observations in the deposits of a postglacial kettle hole, in the county of Västernorrland." Thesis, Umeå universitet, Institutionen för idé- och samhällsstudier, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171994.

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The increased human impact on the environment and climate after the retreat of the Last Glacial has strengthened its importance in the region of Västernorrland where Mesolithic sites are evident. This study focuses on a multiproxy analysis, where archaeological and natural science methods are combined to test several techniques in a peat sample. The origin of the peat sample is coming from the formation of a postglacial kettle hole situated near to Mesolithic sites. The aim of this thesis is twofold. Firstly, to estimate the value and the weakness of each method as also the combination of multiple results. Secondly, to reconstruct the palaeoenvironment including the detection of possible indications from past cultures. To begin with, the peat sample was collected from a kettle hole near Lillsjön lake, see (fig. 1) in 2010. The total depth of the peat sample was 80 cm and after its sampling, it was placed in a cold storage room until the spring of 2019, when analysis was conducted. Initially, a theoretical background will be presented as well as information for the area of study in the section of Scientific background. Moreover, a short theory is going to be given for the formation of the landscapes in cold environments as also the validity of beetle fossils with examples from previous case studies. After the theory part, all the methods are specified with results and appropriate diagrams and tables. After the analysis, the discussion will follow by combining all the methods and give potential theories for the reconstruction of the palaeoenvironment. The discussion part is divided into smaller chapters and after the conclusion an appendix is given with fossil photographs that were taken during the identification, see (fig.15,16,17).

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Du, Plessis Nadia. "4000 years of environmental and climate change at Eilandvlei : a palynological investigation into the late Holocene palaeoenvironment of the Wilderness Embayment." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/15527.

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It is a well-known fact that the South African palaeoenvironmental record is fairly limited, mainly because the environmental conditions here do not lend themselves to the preservation of proxy data sources. This being said, new evidence is emerging from the Wilderness Embayment along the Southern Cape coast of South Africa. This area is of particular interest from a palaeoclimate perspective due to its location within the small year round rainfall zone of South Africa, while the presence of both Fynbos and Afrotemperate forest within this region further highlights the importance of studies in the area. This study presents a new high resolution late Holocene pollen and charcoal record from Eilandvlei, extending from c. 3 800 cal yr BP to present. The record is marked by several significant periods -- largely corresponding to the timing of the three events that typify the late Holocene: the Neoglacial, the Medieval Climate Anomaly and the Little Ice Age. The record also encompasses the arrival of European colonists in the region ca. 1800 AD, marked by the appearance of Pinus, with subsequent notable fluctuations in other taxa, e.g. Podocarpus and Stoebe-type, possibly the expression of the anthropogenic effect on the landscape. This high resolution record thus highlights significant, albeit short term, fluctuations in climate and vegetation patterns along the Southern coast of South Africa and adds to the inadequate records available for the region thus far.

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Écochard, Émilie. "Approche géoarchéologique et valorisation du patrimoine géomorphologique autour du Létôon (plaine de Xanthos, Turquie)." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1022.

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Ce travail propose une reconstitution de l'évolution de l'environnement de la plaine terminale de l'Eşen Çayı depuis le milieu de l'Holocène, avec une attention particulière pour l'environnement proche du sanctuaire du Létôon et de la cité de Xanthos, durant leur période d'occupation (du viie siècle av. J.-C. jusqu'à la période byzantine). La démarche retenue déploie trois approches. L'approche historique, d'abord, confronte les sources archéologiques, historiques, littéraires et géomorphologiques pour définir les enjeux de cette recherche et cerner les questions auxquelles elle doit répondre : l'objectif est de mieux comprendre les sociétés qui ont occupé cet espace et leur relation avec leur environnement. L'approche géo archéologique, ensuite, y répond en s'appuyant sur les données géophysiques (résistivité électrique) et l'analyse des séquences carottées (étude des sédiments, datations). Il apparaît qu'à l'époque de l'occupation des sites, les lagunes qui occupaient auparavant cet espace avaient laissé place à des marais. Un changement dans le tracé de l'Eşen Çayı (un bras du fleuve s'installe temporairement devant le Létôon) facilite l'accessibilité du site depuis la mer, mais l'alluvionnement et la mobilité fluviale qui en résultent mettent aussi en danger les édifices, dès le iiie siècle ap. J.-C. C'est seulement avec la mise en culture systématique de la plaine, durant la deuxième moitié du xxe siècle, que les marais disparaissent et que la plaine est assainie et drainée. L'approche patrimoniale, enfin, permet une réflexion épistémologique et empirique sur la communication des résultats en direction des archéologues commanditaires, du public de visiteurs des sites et des habitants de la plaine. Le concept de géomorphosite, qui fournit une profondeur temporelle à un site aux caractères géomorphologiques remarquables est sollicité pour définir la plaine de Xanthos comme un archéo-géomorphosite
This work reconstructs the changing environment of the plain of the Eşen Çayı from the mid-Holocene period, paying particular attention to the environment around the shrine of Letoon and the city of Xanthos, at the time of their occupation (from the seventh century BC until the Byzantine period). The subject is examined using three different approaches. First, the historical approach compares the archaeological, historical, literary and geomorphological sources to define the boundaries of this research and identify relevant issues : the aim is to better understand the societies which occupied this space and their relationship with the surrounding environment. The geoarchaeological approach then answers these questions, relying on geophysical data (electrical resistivity) and cored sequence analysis (study of sediments, dating). It seems that when the sites were inhabited, lagoons which formerly occupied this area had been replaced by swamps. A change in the flow of the Eşen Çayı (an arm of the river which moved temporarily towards the Letoon) allowed access to the site from the sea, but the buildings were threatened by the river's silting and consequent changes of course (around the third century AD). It is only with the systematic agricultural use of the plain, in the second half of the twentieth century, that the marshes disappeared and the plain was drained and reclaimed. Finally, the heritage approach allows an epistemological and empirical discussion of the communication of results to archaeologists, site visitors and inhabitants of the plain. The concept of geomorphosite, which provides time depth to a site with remarkable geomorphological character, is used to define the plain of Xanthos as an archaeo-geomorphosite

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Brysch, Sven [Verfasser], and Wolfgang [Akademischer Betreuer] Stinnesbeck. "Changes in climate and palaeoenvironment during the Late Jurassic–Early Cretaceous in southern South America and western Antarctica / Sven Brysch ; Betreuer: Wolfgang Stinnesbeck." Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177044064/34.

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Galimberti, Mariagrazia. "Investigation the use of oxygen and carbon isotopes and sclerochronology on Turbo sarmaticus and Donax serra for palaeoenvironment reconstruction at Pinnacle Point, South Africa." Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/10516.

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Includes bibliographical references (p. 241-272).
This thesis investigates the validity of oxygen isotope analysis for the gastropod Turbo sarmaticus (operculum and shell) and the bivalve Donax serra to reconstruct sea surface temperatures. These are the species most commonly retrieved from archaeological assemblages of the South Coast of South Africa. The material analysed for this thesis includes modern and archaeological shells from Pinnacle Point, Mossel Bay. Evidence of human occupation of coastal caves here dates as far back as 164 kya. Specimens analysed for this study date between 114 and 91 ky. Analysis of edge increments shows that all the archaeological specimens were collected in winter and/or in spring and autumn, pointing to seasonal exploitation; the first documentation of this kind of seasonal scheduling of activities in Middle Stone Age sites in South Africa.

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Expósito, Barea Isabel. "Aproximaciones metodológicas desde la arqueopalinología a contextos antropogénicos de la Sierra de Atapuerca (Burgos) y a secuencias naturales del litoral mediterráneo." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/668790.

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Aquest treball es basa en l’anàlisi palinològica des de la perspectiva de l’antropització pel que fa a la reconstrucció de l’entorn vegetal en el que es van desenvolupar les activitats de les comunitats humanes durant el Plistocè i l’Holocè a la Península Ibèrica. Amb la intensificació de les seves activitats, les comunitats humanes alteren el medi afavorint la desforestació i la degradació de les comunitats vegetals. Així, a través de l’anàlisi de pol·len i dels palinomorfes no pol·línics (NPPs) de la seqüència de la Cueva de El Mirador (Sierra de Atapuerca, Burgos), s’ha reconstruït la vegetació i el clima durant el Neolític i l’Edat del Bronze. L’anàlisi ha evidenciat la intensitat de la pressió antròpica contribuint al coneixement de la formació d’un dipòsit en fumier. En aquest mateix sentit, la particularitat del reompliment ha motivat la realització de l’anàlisi tafonòmic de l’espectre palinològic del nivell Mir4, enquadrat en l’Edat del Bronze. L’aportació fonamental d’aquest estudi és la descripció de la relació del conjunt de palinomorfes identificat amb les característiques descrites per a les facies sedimentàries de procedència, el que ha contribuït al coneixement dels processos de formació del dipòsit. L’escassa resolució pol·línica que caracteritza els dipòsits sedimentaris Plistocens ha motivat la realització de l’anàlisi dels NPPs de les seqüències de Sima del Elefante, Gran Dolina i Galería (Sierra de Atapuerca, Burgos) ratificant la idoneïtat dels NPPs com indicadors paleoecològics. Per la seva part, els resultats pol·línics i de microcarbons obtinguts de l’estudi de seqüències sedimentàries holocenes de l’àmbit mediterrani de la Península Ibèrica i les Illes Balears han ratificat la importància dels incendis i l’antropització en la formació de la vegetació mediterrània. Finalment, les incògnites generades pels treballs realitzats, han motivat la posta en marxa d’un programa d’experimentació destinat a contrastar les hipòtesis plantejades.
Este trabajo parte del análisis palinológico desde la perspectiva de la antropización para la reconstrucción del entorno vegetal en el que se desarrollaron las actividades humanas durante el Pleistoceno y Holoceno en la Península Ibérica. Con la intensificación de sus actividades, las comunidades humanas alteran el medio favoreciendo la deforestación y la degradación de las comunidades vegetales. Así, a través del análisis del polen y los palinomorfos no polínicos (NPPs) de la secuencia de la Cueva de El Mirador (Sierra de Atapuerca, Burgos), se ha reconstruido la vegetación y el clima durante el Neolítico y la Edad del Bronce. El análisis ha evidenciado la intensidad de la presión antrópica contribuyendo al conocimiento de la formación de un depósito en fumier. En este mismo sentido, la particularidad del relleno ha motivado la realización del análisis tafonómico del espectro palinológico del nivel Mir4, encuadrado en la Edad del Bronce. La aportación fundamental de este estudio es la descripción del conjunto de palinomorfos identificado con respecto a las características descritas para las facies sedimentarias de procedencia, lo que ha contribuido al conocimiento de los procesos de formación del depósito. La escasa resolución polínica que caracteriza los depósitos sedimentarios Pleistocenos ha motivado la realización del análisis de los NPPs de las secuencias de Sima del Elefante, Gran Dolina y Galería (Sierra de Atapuerca, Burgos) ratificando la idoneidad de los NPPs como indicadores paleoecológicos. Por su parte, los resultados polínicos y de microcarbones obtenidos a partir del estudio de secuencias sedimentarias holocenas del ámbito mediterráneo de la Península Ibérica y las Islas Baleares han ratificado la importancia de los incendios y la antropización en la formación de la vegetación mediterránea. Finalmente, las incógnitas generadas por los trabajos realizados, han motivado la puesta en marcha de un programa de experimentación destinado a contrastar las hipótesis planteadas.
This work considers the palynological analysis from the perspective of anthropization for the reconstruction of the plant environment in which human activities were developed during the Pleistocene and Holocene in the Iberian Peninsula. With the intensification of human activities, human communities alter the environment, favoring deforestation and degradation of plant communities. Thus, through the analysis of pollen and non-pollen palynomorphs (NPPs) of the Holocene sequence of the El Mirador Cave (Sierra de Atapuerca, Burgos), vegetation and climate of Neolithic and the Bronze Age have been reconstructed. The analysis has evidenced the intensity of anthropic pressure and has contributed to the knowledge of the formation of a fumier deposit. The particularity of this infilling has led to the taphonomic analysis of the palynological ensemble of the Mir4 level, framed in the Bronze Age. The main contribution of this study is the description of the relationship of the set of palynomorphs identified with the characteristics described for the sedimentary facies, and has contributed significantly to the knowledge of the deposit formation processes. The low pollen resolution that characterizes the Pleistocene deposits has motivated the analysis of the NPPs of the Sima del Elefante, Gran Dolina and Galería sequences (Sierra de Atapuerca, Burgos) and has ratified the suitability of NPPs as paleoecological indicators. On the other hand, pollen and microcharcoal results obtained from some Holocene sedimentary sequences in the Mediterranean area of the Iberian Peninsula and the Balearic Islands have confirmed the importance of fires and anthropization in the formation of Mediterranean vegetation. Finally, the questions generated by the works carried out, have motivated the implementation of an experimental program aimed at contrasting some of the hypotheses.

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Martin, Emmanuel Laurent Olivier. "Communautés animales du début de l'Ordovicien (en. 480Ma) : études qualitatives et quantitatives à partir des sites à préservation exceptionnelle des Fezouata, Maroc." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1115/document.

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Jusqu'à récemment, l'essentiel de l'information sur les premiers ecosystèmes marins complexes provenait de gisements dits à préservation exceptionnelle, d'âge Cambrien, répartis à travers le globe. Leur caractéristique est de préserver des organismes faiblement sclérotisés, reflétant ainsi fidèlement les faunes de l'époque. Cependant, la découverte de tels sites dans l'Ordovicien inférieur du Maroc permet non seulement d'évaluer pour la première fois avec précision la biodiversité marine de cette époque mais aussi, à qualité de préservation égale, de comparer la vie marine cambrienne et ordovicienne. L'établissement d'un cadre biostratigraphique et envrionnemental précis des niveaux fossilifères a montré que la préservation exceptionnelle était restreinte au sein de deux intervalles stratigraphiquesresserrés datant du Trémadocien supérieur et du Floien moyen. Les donnéessédimentologiques ont mis en évidence un environnement de plateforme peu profond. Ces résultats étaient un prérequis à l'ouverture de fouilles systématiques permettant des analyses paléoécologiques qualitatives et quantitatives à haute résolution. Les résultats préliminairesindiquent l'existence probable de conditions environnementales inhospitalières, du moins temporairement, associées aux niveaux à préservation exceptionnelle. Elles ont également distingué des assemblages in situ (biocénoses) et des associations d'éléments transportés (taphocénoses). Parallèlement, de nouvelles données importantes sur la morphologie, l'écologie, et le mode de vie présumé chez certains groupes ont pu être acquises
Until recently, most of the information on the first complexe marine ecosystems came from Cambrian Konservat-Lagerstätten, distributed all over the world. Their particularity is to preserve a wide array of soft-bodied and lightly sklerotized organisms, accurately reflecting past communities. However, the discovery of such Lagerstätten in the Lower Ordovician ofMorocco offers unique insights into the first animal biodiversifications. Indeed, the Fezouata Shale does not only allow for the time to document Lower Ordovician marine communities, but also to draw comparisons between Cambrian and Ordovician marine realms with the same precision. The establishment of a sound biostratigraphic and palaeoenvironmentalframework for the fossiliferous localities demonstrated that exceptional preservation was restricted to two relatively narrow intervals: a 60-meter-thick late Tremadocian lower interval and a 15-meter-thick middle Floian one. Sedimentological data suggest relatively shallow offshore conditions. These results were a prerequistie to the opening of systematic excavation in order to perform high-resolution quantitative and qualitative palaeocological analyses. Preliminary results point to the likely occurrence of -at least temporarily- unhospitable environmental conditions associated with exceptional preservation. They also enabled the recognition of original in situ communities (biocoenoses) and time-averaged associations including transported elements (taphocoenoses). Simultaneously, important new data on the morphology, ecology and presumed mode of life of fossil groups have been collected

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Perner, Melissa Josephine [Verfasser], and Wolfgang [Akademischer Betreuer] Stinnesbeck. "Evolution of Palaeoenvironment, Kerogen Composition and Thermal History in the Cenozoic of the Northern Upper Rhine Graben,SW-Germany / Melissa Josephine Perner ; Betreuer: Wolfgang Stinnesbeck." Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177385805/34.

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Choa, Omar. "A geochemical history of Tabon Cave (Palawan, Philippines) : environment, climate, and early modern humans in the Philippine archipelago." Thesis, Paris, Muséum national d'histoire naturelle, 2018. http://www.theses.fr/2018MNHN0002/document.

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La grotte de Tabon (Palawan, Philippines) est un site préhistorique majeur en Asie du Sud-Est. Elle a livré des fossiles d’Homo sapiens datant du Pléistocène supérieur, rares dans la région. Pourtant, son histoire demeure mal connue : d’importantes altérations physiques et chimiques compliquent la lecture de sa stratigraphie, tandis que des objets archéologiques sans contexte clair entravent l’élaboration d’une chronologie fiable. Cette étude jette un nouveau regard sur la grotte de Tabon à travers une approche pluridisciplinaire des sciences de la Terre. Elle explore notamment l’environnement et le climat des premiers hommes anatomiquement modernes dans la région. Les résultats mettent en lumière une période clef entre 40 et 33 ka BP, caractérisée par des climats plus secs, des paysages plus ouverts et une empreinte humaine marquée dans la grotte. Cette période a également été ponctuée par un court épisode d’humidité qui a laissé un spéléothème gypsifère étendu en guise de témoin. Dans l’avenir, de nouvelles approches, prenant en compte les contraintes particulières du site, pourraient permettre de souligner davantage la valeur scientifique et patrimoniale unique de la grotte de Tabon, une fenêtre sur les premiers périples de notre espèce à travers les archipels d’Asie du Sud-Est
Tabon Cave (Palawan, Philippines) is a key prehistoric site in Southeast Asia, one of the few to have yielded Homo sapiens fossils from the Late Pleistocene. Its history remains poorly understood: heavy physical and chemical alterations have greatly complicated its stratigraphy, and contextually isolated archaeological finds hamper the construction of a clear chronology. This study reexamines Tabon Cave using a multi-pronged geosciences approach to explore environment, climate, and early modern human presence in the region. The results reveal a major period in the cave’s history between 40 and 33 ka BP, when drier climates, more open landscapes, and active human use of the cave were briefly spaced by a wet episode that left an extensive, gypsiferous speleothem. Future innovative research approaches spurred by the unique constraints of the site will undoubtedly further highlight the unique scientific and heritage value of Tabon Cave, a window into the earliest odysseys of our species across the archipelagos of Southeast Asia

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Qvarnström, Martin. "Palaeoenvironments of the Earliest (Middle Devonian) Tetrapod Trackways from the Holy Cross Mountains, Poland; Locomotion in a Terrestrial Setting?" Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-319968.

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The palaeoenvironment from which early tetrapods emerged is crucial to comprehend in order to understand the mechanisms that drove and allowed the terrestrialization of vertebrates; one of the most important evolutionary ‘events’ in the history of animals. Nevertheless, much of the terrestrialization is shrouded in obscurity, inter alia, due to scarcity of early tetrapods in the fossil record. Each new discovery of anything linked to vertebrate terrestrialization is therefore of great importance. Here, I present new detailed analyses of the palaeoenvironmental conditions at the time of formation of the earliest (early Middle Devonian) tetrapod trackways found in the Zachełmie Quarry in the Holy Cross Mountains of southern Poland. The trackways are found in three horizons in a clay-rich dolomitic succession represented by the Lower Complex of the Wojciechowice Formation. This Lower Complex is composed of short shallowing upward sequences that often terminate with desiccation cracks and/or paleosols. Vertically fluctuating δ18O values in the complex suggest multiple episodes of closed hydrological systems. A model of ephemeral to perennial lakes in a terrestrial setting is therefore proposed. Such environment is in concordance with evidence of scarce bioturbation and a flourish of microbial communities that, in contrast to a normal marine setting, most likely represent an ecologically stressed ecosystem. Furthermore: non-marine rare earth element (REE) signals, desiccation events, fossils of green algae (charophytes), paleosol development, low energy cyclic deposits and general lack of marine taxa in the body and trace fossil records in this complex firmly establishes the interpretation of palustrine carbonates formed in a lacustrine-like setting. However, in the lower part of the complex, some highly fractioned marine fossils occur. These are suggested to have been transported during wash-up events which temporally places the setting in marine proximity. Seasons of monsoonal rainfall resulted in erosion and influx of detrital grains which is evidenced by fine planar lamination (of seasonal cyclicity) in most of the sediments and occasional occurrence of blackened clasts (and rain-drop imprints).Thus, none of the pre-existing palaeoenvironmental hypotheses of tetrapod emergence are in full concordance with the data from the Zachełmie Quarry. Instead, a new palaeoenvironment is proposed for the earliest tetrapods: schizohaline ephermal to perennial lakes with periodic desiccation. This infers that already in the early Middle Devonian, tetrapods had conquered the terrestrial realm and were perhaps already capable of terrestrial locomotion over quite substantial distances.
Däggdjur, reptiler, fåglar och amfibier utgör tillsammans en besläktad djurgrupp som kallas för tetrapoder (fyrfotingar). Deras gemensamma förfader härstammade från de lobfenade fiskarna men skiljde sig från dem genom att inneha utvecklade ben med tår istället för de ”köttiga” fenor som de lobfeniga fiskarna karaktäriseras av. Denna evolutionära nyhet tillät, tillsammans med en rad andra egenskaper (lungor, skydd för uttorkning av dermis etc.), att vertebrater helt och hållet kunde koloni-sera land. I och med att vår egen existens är en direkt följd av denna evolutionära händelse är detta ett hett forskningsämne inom evolutionsbiologin. Ändå är mycket fortfarande höljt i dunkel beträffande hur koloniseringen av land gick till och vad det var som drev denna utveckling eftersom övergången skedde under en, i geologisk mått, snabb tidsrymd. Dock har de sista årtiondena resulterat i flertalet nya fossilfynd av primitiva tetrapoder. Ett fynd som är speciellt spektakulärt eftersom det är den hittills äldsta efterlämningen av tetrapoder, är fotspår som uppenbart är gjorda av ett djur som hade ben och tår istället för fenor. Detta förvånade hela det vetenskapliga samfundet eftersom det innebar att vi (tetrapoderna) utvecklades tidigare än vad som var dittills trott och att vertebrat-koloniseringen av land förmodligen skedde flertalet miljoner år tidigare. Vad som också skiljer ett spårfossil från andra fossil är att de är spår av djuren från när och där de levde till skillnad från bara deras skelettdelar som oftast transporterats från där de dog och bara preserveras i speciella miljöer. Detta har jag utnyttjat i detta arbete för att försöka avgöra i vilken miljö de är avsatta i. Jag har analyserat de sedimentära bergarterna i stenbrottet i södra Polen med skärningen som innehåller de lagren i vilka fotspåren finns. Analyser av sällsynta jordartsmetaller från de tre lager där fotspår är tydliga, antyder en speciell avsättningsmiljö som inte liknar en typisk havsmiljö. I den undre delen av lagerföljden där de spårbärande lagren påträffats finns återkristalliserade saltkristaller, torkningssprickor och fossila jordar som indikerar korta respektive långvariga perioder av uttorkning. Andra fossil som i en normal marin miljö borde bevaras i en dolomitisk kalksten lyser med sin frånvaro och istället påfinns massiv koloni-sering av cyanobakterier. Detta brukar ske i speciella miljöer som avviker från vanlig marin komposi-tion, så som äldre sötvattensmiljöer eller laguner med hög salthalt, som därmed är ”svårbebodd” för djur som annars livnär sig på de fotosyntiserande bakterierna. Implikationen av mitt arbete är att tetrapoderna redan i tidig mellan Devon (ca 390 miljoner år sedan) inte bara hade utvecklat ben utan också att de kunde använda dem över landsträckor för att ta sig till, och mellan, kontinentala vatten. Detta är ännu en viktig pusselbit i pusslet som ämnar rekonstruera tetrapodernas (och vår egen) uppkomst.

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Kneip, Andreas. ""O povo da lagoa: uso do SIG para modelamento e simulação na área arqueológica do Camacho"." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/8/8153/tde-13102004-172248/.

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Os dados obtidos da topografia, da geomorfologia, do sensoriamento remoto para a região do Camacho, litoral sul de Santa Catarina, foram reunidos e integrados no SIG GRASS. Durante a ocupação desta região pela população pré-histórica, de aproximadamente 5000 anos Antes do Presente (anos AP) até 1000 anos AP, o nível médio marinho local caiu aproximadamente 2m. Como a região é muito plana, esta regressão implicou em uma grande alteração da extensão da laguna, e, portanto, da área para coleta de moluscos e para pesca. O tipo e o tamanho dos peixes capturados, cujos restos podem ser encontrados nos sítios arquológicos deixados por este povo, permitem concluir que provavelmente os antigos moradores possuiam tecnologia de pesca, como barcos e redes. Ao redor da laguna estão espalhados mais de 50 sambaquis, alguns com centenas de milhares de metros cúbicos de volume. Pesquisa em alguns destes sítios mostram que tinham a função de cemitérios. Alguns destes sambaquis são contemporâneos. Com o tempo, antigos sambaquis eram abandonados e novos começavam a ser construídos. O objetivo deste trabalho é contribuir no entendimento desta ocupação através da relação espacial que os sambaquis mantinham entre si e com a paisagem ao seu redor. Com os dados da topografia foi possível construir o Modelo de Elevação Digital da região. As informações geomorfológicas, geológicas e topográficas, reunidas e integradas no SIG, permitem simular a movimentação do nível médio do mar (NMM) no período desde aproximadamente 5000 anos AP até o momento atual. Modelos desenvolvidos no GRASS mostram a lagoa como espaço principal de circulação deste povo.
Data from the Camacho region, southern coast of the Santa Catarina state, southern Brazil, were collected and combined in the GIS GRASS. This region is a coastal plain, with many lagoons, and was occupied by a prehistoric population at least from c. 5,000 years before present (BP) to 1,000 years BP. In this period, the local mean sea level had fallen c. 2 m. As the region is very flat, this regression implied a reduction in the lagoon area, and consequently a reduction in the catchment area for these people. At the edges of the nowadays lagoons there are more than 50 shell mounds, some with volume greater than 100,000 m${}^3$, where the dead were buried. Some of that shell mounds are contemporary and were in use for thousand of years, but as the time passed, the ancient sites were abandoned and new sites began to be constructed. The objective of this work is to contribute to a better understanding of the spacial relationship between the shell mound and the landscape of the region. For this purpose the information about geology, geomorphology, topography, and datations were gathered and integrated in GRASS. A Digital Elevation Model was constructed and the movement of the mean sea level was simulated. The results are consistent with the occupation of the region. Other models, developed in GRASS, show that the lagoon was the main route of circulation of the prehistoric people.

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CLO', ELEONORA. "Cambiamento climatico e impatto antropico su lunga scala temporale: analisi palinologica di depositi della Pianura Padana centrale a partire dal Tardoglaciale." Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2022. http://hdl.handle.net/11380/1278300.

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La Pianura Padana ha fatto da teatro a complesse relazioni dinamiche tra uomo ed ecosistema fluviale che sono le basi di una vera e propria rivoluzione culturale, sicuramente favorita dalla posizione strategica di questo territorio posto tra il Mediterraneo e l'Europa continentale. Questa ricerca si pone l'ambizioso obiettivo di indagare i cambiamenti ambientali avvenuti nella pianura alluvionale del fiume Po durante l'Olocene, come conseguenza di fattori climatici e azioni antropiche che hanno modificato il territorio a scala locale e regionale. A tal fine, tre carotaggi terrestri sono stati eseguiti a diverse distanze dalla Terramara S. Rosa di Poviglio, indagata da oltre 35 anni grazie a numerose campagne di scavo dirette da M. Bernabò Brea, M. Cremaschi, e negli ultimi anni A. Zerboni. Tutte le autorizzazioni allo scavo e al campionamento sono state concesse dal SABAP-BO (MiC) al Dipartimento di Scienze della Terra “A. Desio” dell'Università degli Studi di Milano. I carotaggi sono stati inclusi nel progetto SUCCESSO-TERRA (PRIN-20158KBLNB; coord. M. Cremaschi, A. Zerboni - Università degli Studi di Milano). I carotaggi sono stati nominati PVG N-S3 (Near-S3), PVG C-S1 (Central-S1) e PVG F-S2 (Far-S2) in accordo con le diverse distanze di campionamento dal sito archeologico. Campioni pollinici sono stati prelevati lungo tutte le carote ma solo la N-S3 è stata analizzata interamente (77 campioni), mentre l'analisi palinologica delle altre sequenze è stata effettuata sui livelli più recenti secondo l’obiettivo di indagare i cambiamenti della vegetazione durante l'Olocene (90 e 28 campioni rispettivamente per C-S1 e F-S2). La cronologia è ancora in una fase preliminare, alcune date al radiocarbonio sono state rifiutate per problemi di sovrastima riferibili all’effetto serbatoio, e presto sarà implementata con luminescenza otticamente stimolata e possibili correlazioni con altre sequenze campionate nell'area di studio. Quattro zone polliniche sono state identificate in accordo con i risultati della cluster analysis e all'analisi visiva delle curve polliniche. Gli spettri pollinici ottenuti forniscono una dettagliata immagine dei cambiamenti della vegetazione su larga scala grazie alla presenza di caratteristiche coerenti e possibili correlazioni lungo tutte le sequenze. Allo stesso tempo, il campionamento dei tre carotaggi a breve distanza l'uno dall'altro permette di indagare evidenze locali, tra cui la principale è la diminuzione della pressione antropica a maggiore distanza dall'insediamento. Diverse elaborazioni statistiche (Principal Component Analysis and Multivariate Curve Resolution-Alternating Least Squares) hanno contribuito positivamente alla discussione delle informazioni ottenute dai dati pollinici. L’analisi multivariata MCR-ALS non è mai stata applicata in Palinologia e i risultati ottenuti rivelano le potenzialità di questo metodo per indagini palinologiche. L'applicazione di metodi statistici per la ricostruzione quantitativa della vegetazione da dati pollinici è stata approfondita presso l'Università di Bergen (Norvegia). In accordo con la stratigrafia e il confronto con le principali sequenze polliniche di riferimento per l'area di studio, i livelli più profondi delle carote intercettano probabilmente la maggior parte del Tardoglaciale. Gli eventi climatici e impronta ecologica dell'influenza umana sull’ecosistema si riflettono sicuramente negli spettri pollinici come parte di un unico complesso sistema dinamico, da tempi in cui le dinamiche climatiche ed ecosistemiche erano i principali fattori dei cambiamenti della vegetazione ad altri in cui l’impatto delle popolazioni umane ha un ruolo sempre più permanente ed esteso sull'ambiente fino alla condizione attuale.
As a floodplain in which complex human–water systems with dynamic behaviors were established, the Po Plain is considered a key area for the interpretation of long-term relationship between human populations and the environment because of the strategic location between the Mediterranean and continental Europe. This research focuses on the ambitious aim of investigating local and regional environmental changes that occurred in the Po River floodplain as a twofold result of climate changes and human actions during the Holocene. To reach the goal, three terrestrial cores were drilled in the Central Po Plain at different distances from the Terramara S. Rosa di Poviglio, which has been investigated for more than 35 years thanks to the archaeological excavation directed by Maria Bernabò Brea, Mauro Cremaschi and, and in recent years, Andrea Zerboni. All authorizations to carry out the excavation and sampling has been released by the SABAP-BO (MiC) to the Dipartimento di Scienze della Terra “A. Desio” of the Università degli Studi di Milano. The cores were included in the SUCCESSO-TERRA Project (PRIN-20158KBLNB; P.I. M. Cremaschi, A. Zerboni – Università degli Studi di Milano). Concerning the different distances from the archaeological site at which the cores were drilled, it has been decided to name the sequences PVG N-S3 (Near-S3), PVG C-S1 (Central-S1) and PVG F-S2 (Far-S2). Pollen samples were taken throughout the depth of the cores but only the N-S3 core was analysed entirely (77 samples), while palynological analysis of the other cores was carried out for more recent levels according to the focus of the detection of vegetation changes during the Holocene (90 and 28 samples were analysed for the C-S1 and the F-S2 core, respectively). Problems with the reliability of radiocarbon dates influenced by the reservoir effect was attested. Chronology is still in a preliminary stage and will be updated soon with Optically Stimulated Luminescence and possible correlations with other cores in the study area. Four main pollen zones describing events and flora and vegetation transformations were identified according to the cluster analysis and visual examination. Pollen spectra show consistent trends and possible correlations throughout the three cores with a long-term picture of large-scale vegetation changes. At the same time, the collection of the three cores at short distances from each other offers the great opportunity to investigate different features and local variations, among which the main evidence is the decrease in anthropogenic pressure at a greater distance from the settlement. Different statistical elaborations (Principal Component Analysis and Multivariate Curve Resolution-Alternating Least Squares) have provided consistent results which contributed positively to the discussion of the detailed information from pollen data. MCR-ALS has never been applied in Palynology and the results obtained reveal the potential of this method for palynological investigations. The application of statistical methods for quantitative reconstruction of vegetation from pollen data have been deepened at the University of Bergen (Norway). According to the stratigraphy and the possible comparison with the main reference pollen records for the study area, the bottom of the cores could be probably intercepted most of the Lateglacial. Climatic events and the human footprint are certainly reflected in the pollen spectra as part of a single complex dynamic system, from times when climate and ecosystem dynamics were the main factors of vegetation changes to others in which human populations play an increasingly important role with a permanent and extensive impact on the environment up to the current condition.

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Lindeque, Ansa [Verfasser], Karsten [Akademischer Betreuer] Gohl, Heinrich [Akademischer Betreuer] Miller, and Cornelia [Akademischer Betreuer] Spiegel. "Palaeoenvironment of the Weddell Sea and Amundsen Sea - eastern Ross Sea basins, Antarctica: Insights from comprehensive seismostratigraphic analysis / Ansa Lindeque. Betreuer: Karsten Gohl. Gutachter: Heinrich Miller ; Cornelia Spiegel." Bremen : Staats- und Universitätsbibliothek Bremen, 2014. http://d-nb.info/109639121X/34.

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Esteban, Lopez Sarah [Verfasser], Hans-Georg [Gutachter] Herbig, and Martin [Gutachter] Melles. "Conodonts, microfacies and palaeoenvironment during the mid-Tournaisian Event - comparison of platform and basin (lower Mississsippian, Germany and Belgium) / Sarah Esteban Lopez ; Gutachter: Hans-Georg Herbig, Martin Melles." Köln : Universitäts- und Stadtbibliothek Köln, 2020. http://d-nb.info/1233783157/34.

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Schneider, Anton Christoph [Verfasser], Jörg [Gutachter] Mutterlose, and Ulrich [Gutachter] Heimhofer. "Stratigraphy, palaeoenvironment, and hydrocarbon potential of a non–marine sedimentary sequence : the Jurassic-cretaceous boundary interval in northern Germany / Anton Christoph Schneider ; Gutachter: Jörg Mutterlose, Ulrich Heimhofer ; Fakultät für Geowissenschaften." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1202608744/34.

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Meszner, Sascha [Verfasser], Dominik [Akademischer Betreuer] Faust, Ludwig [Gutachter] Zöller, and Pierre [Gutachter] Antoine. "Loess from Saxony : A reconstruction of the Late Pleistocene landscape evolution and palaeoenvironment based on loess-palaeosol sequences from Saxony (Germany) / Sascha Meszner ; Gutachter: Ludwig Zöller, Pierre Antoine ; Betreuer: Dominik Faust." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1119362245/34.

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Lim, Sophak. "50,000 years of vegetation and climate change in the Namib Desert." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT150/document.

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Cette thèse présente les données des pollens et micro-charbons fossiles couvrant la période des 50 000 dernières années à partir de sites sélectionnés transversalement nord-sud du désert de Namib. Dans le cadre de cette thèse, on utilise le rock hyrax middens, l’accumulation des boulettes et des urines fossilisés du Procavia capensis, représentant une excellente archive pour archives pour la préservation des pollens et micro-charbons à long-terme. Trois sites des hyrax middens ont été sélectionnés pour l'analyse: au sud du désert de Namib (Pella), la marge est des dunes de sable de Namib (Zizou) et le centre de la Namib (Spitzkoppe). En plus, le régime pluvial de ces sites se caractérise par une forte variabilité annuelle et interannuelle. En conséquence, tous ces sites se situent au long de l’écotone du Désert et du biome Nama-Karoo, ainsi qu'à l’est (biome de Savane). Alors que ces sites sont répertoriés dans des écosystèmes similaires, l’écotone, lui, est considéré comme une zone potentiellement très sensible au changement du système climatique régional. Un intérêt spécifique de ces enregistrements terrestres est pour évaluer s’ils corroborent ou s’opposent avec les résultats provenant ceux des sédiments marins de la côte namibienne, en particulier la conclusion : l’abondance des taxa dominants du Fynbos Biome du Cape peut indiquer significativement une expansion vers le nord de la flore du Cape pendant les périodes plus froides glaciaires. Selon les sites d’études sélectionnées, les conclusions principales de ce travail sont les suivantes:Les hyrax middens de Pella fournissent le premier enregistrement pollinique continué au sud du désert de Namib durant la période des 50 000 dernières années. Ces données polliniques ont permis de reconstruire le changement de la végétation et d'estimer la température et l'aridité. Les résultats indiquent que la période glaciaire se caractérise par une augmentation de la disponibilité de l'eau sur le site par rapport à l'Holocène. Les changements de la température et de l'évapotranspiration potentielle semblent avoir joué un rôle important dans la détermination de l'équilibre hydrologique.L'enregistrement de Zizou hyrax midden met en évidence des changements de la végétation à la marge l'est des dunes de sable depuis 38 000 ans cal BP. La végétation de la période glaciaire se caractérise par les pourcentages relativement élevés des Astéracées pollen, et plus particulièrement par des taxa du climat plus froid: Stoebe et Artemisia¬-type. En accord avec les données de Pella, le réchauffement au début de l'Holocène indiqué par la dominance de pollen des graminées dans l'assemblage pollinique suggère une expansion du biome de Désert.Les hyrax middens de Spitzkoppe enregistrent les changements de la végétation dans le centre du désert de Namib au cours des 32 000 dernières années. Les résultats sont globalement cohérents en comparant aux autres enregistrements terrestres dans la région. L'analyse de ces données n'est cependant pas encore terminée.Dans tous ces sites, une variabilité significative a été observée à la fois dans la dernière période glaciaire et l'Holocène. Les conditions plus froides de l'ère glaciaire semblent être caractérisées par une augmentation de la disponibilité de l'eau le long de la totalité de notre zone d'étude. Au contraire des résultats provenant des carottes marines, nos enregistrements indiquent aucune expansion de la végétation de Fynbos biome, et seulement des traces de Restionaceae pollen dans le site extrêmement au sud à Pella (pas plus de 1%), mais aucun trace de ce pollen n'ayant été observé à Zizou ainsi qu’à Spitzkoppe
This thesis presents fossil pollen and microcharcoal data during the last 50,000 years from a north-south transect of the Namib Desert. The arid environment of the Namib precludes the development of permanent wetlands, and as a result few palaeoenvironmental records exist from the region. In this study, we employ rock hyrax middens – fossilised accumulations of the faecal pellets and urine of the Procavia capensis. Hyrax middens from three sites were selected for analysis: the southern Namib (Pella), the eastern margin of Namib Sand Sea (Zizou), and the central Namib (Spitzkoppe). The results from these terrestrial sites are the extent to which they may corroborate or conflict with findings from pollen records obtained from marine sediments of the Namibian coast.The Pella hyrax middens provide the first continuous pollen record from the southern Namib Desert since the last 50,000 years, and are used to reconstruct vegetation change and quantitative estimates of temperature and aridity. Results indicate that the last glacial period was characterised by increased water availability relative to the Holocene. Changes in temperature and potential evapotranspiration appear to have played a significant role in determining the hydrologic balance. The record can be considered in two sections: 1) the last glacial period, when low temperatures favoured the development of more mesic Nama-Karoo vegetation at the site, with periods of increased humidity concurrent with increased coastal upwelling, both responding to lower global/regional temperatures; and 2) the Holocene, high temperatures and potential evapotranspiration resulted in increased aridity and an expansion of the Desert Biome.Considered in the context of discussions of forcing mechanisms of regional climate change and environmental dynamics, the results from Pella stand in clear contrast with many inferences of terrestrial environmental change derived from regional marine records. Observations of a strong precessional signal and interpretations of increased humidity during phases of high local summer insolation in the marine records are not consistent with the data from Pella. Similarly, while high percentages of Restionaceae pollen has been observed in marine sediments during the last glacial period, they do not exceed 1% of the assemblage from Pella, indicating that no significant expansion of the Fynbos Biome has occurred during the last 50,000 years.The Zizou hyrax midden highlights vegetation changes on the eastern margin of the Namib Sand Sea since 38,000 cal BP. Results show the different vegetation compositions between the last glacial period and the Holocene. Glacial vegetation characterised with relatively high percentages of Asteraceae pollen, particularly cool climate taxa such as Stoebe and Artemisia types. Similar to the data from Pella, with the onset of Holocene warming grass pollen comes to dominate the assemblage, suggesting an expansion of the Desert Biome. We suggest that the climate during the last glacial period was more humid, and supported the development of shrubs/small trees. Arid conditions during the Holocene saw the depletion of this resource, and the development of grasslands that could exploit the rare rains that the region experiences today. In common with the Pella record, no elements of the Cape flora are found in the Zizou middens.The Spitzkoppe hyrax middens record vegetation changes in the central Namib during the last 32,000 years. The last glacial vegetation compositions composed of Olea, Artemisia¬-type, Stoebe¬-type and grasses. In the Holocene, the arboreal taxa such as Olea was replaced by others like Eculea, Dombeya, Commiphora, and Croton¬-type with relative higher percentage of grasses at early Holocene

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Cantuel, Jean. "Les apports de l'archéozoologie à notre connaissance du Néolithique égéen." Thesis, Clermont-Ferrand 2, 2010. http://www.theses.fr/2010CLF20023.

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Ce travail a pour objectif de mieux comprendre l’économie animale dans le monde égéen néolithique. Il s’appuie d’une part sur l’étude archéozoologique de trois sites localisés dans le Péloponnèse et en Macédoine : Kouphovouno, Pigi Athinas et Kryoneri. D’autre part, des analyses de micro-usures ont été réalisées sur les dents d’animaux des assemblages ostéologiques de Kouphovouno, Lerne, Kitsos, Pigi Athinas, Kryoneri et Sitagroi afin de restituer les conditions d’élevage et l’environnement passé. Ces données ont ensuite été intégrées dans une perspective géographique et chronologique plus large, ce qui nous a permis de révéler une adaptation optimale de l’homme au milieu et aux contraintes socio-économiques tant dans les choix d’élevage que dans l’exploitation de la faune elle-même
The objective of this work is to increase our knowledge of animal economy during the Neolithic in the Aegean. This study is uses archaeozoological studies of three settlements located in Peloponnese (Kouphovouno) and Macedonia (Pigi Athinas and Kryoneri) as well as, dental microwear on the animal teeth from six assemblages, Kouphovouno, Lerna, Kitsos, Pigi Athinas, Kryoneri and Sitagroi in order to reconstruct conditions of breeding and the paleoenvironment. These data are then placed in the context of a wider geographical and chronological perspective, what allows us to reveal an optimal adaptation of man to his environment and to socio-economic constraints both in choices of breeding and in exploitation of the fauna itself

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Bento, Da Costa Laura. "Paléobiologie et paléoenvironnements au Miocène inférieur : apport des rongeurs aux corrélations inter-régionales en Afrique sub-saharienne." Electronic Thesis or Diss., Sorbonne université, 2020. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2020SORUS182.pdf.

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Depuis des années, les rongeurs sont étudiés pour la diversité de leurs adaptations locomotrices. Cette dernière est représentée dans le registre fossile des gisements du Miocène inférieur de Napak (Karamoja, Ouganda) et de Grillental, Elisabethfeld et Langental (Sperrgebiet, Namibie). Plusieurs espèces ont été étudiées : Paranomalurus bishopi, Paranomalurus walkeri, Nonanomalurus soniae, Renefossor songhorensis (Napak), Bathyergoides neotertiarius (Namibie) et Diamantomys luederitzi (représentée dans les deux régions). Après avoir actualisé leur systématique, les analyses morphométriques ont permis la prédiction de leur locomotion via leur crâne, humérus, ulna et fémur. Ces adaptations sont liées à la stabilisation et mobilité des membres, les arboricoles privilégiant une mobilité plus accrue, tandis que les terrestres et fouisseurs favorisent la stabilisation. Ainsi, les espèces du genre Paranomalurus sont prédites comme planeuses, N. soniae arboricole, et B. neotertiarius fouisseuse. D. luederitzi est considérée comme une espèce généraliste. La variabilité de ces comportements souligne une hétérogénéité des environnements Miocène, démontrée par les analyses isotopiques des δ13C et δ18O des carbonates de leur émail dentaire. En effet, l’analyse indique un milieu ouvert à plantes C3 dominantes avec la présence d’îlots boisés (savane arborée), confirmé par les locomotions de ces espèces. Ces rapports isotopiques couplés avec ceux des grands mammifères indiquent un environnement plus humide et/ou à température moins élevée qu’aujourd’hui dans ces localités, la région namibienne étant moins humide et potentiellement plus chaude que l’Afrique de l’Est à cette époque
For several years, rodents have been studied because of their various locomotor adaptations. This diversity is represented in the fossil record of the lower Miocene sites of Napak (Karamoja, Uganda) and Grillental, Elisabethfeld and Langental (Sperrgebiet, Namibia). This study focusses on several species: Paranomalurus bishopi, Paranomalurus walkeri, Nonanomalurus soniae and Renefossor songhorensis (Napak), Bathyergoides neotertiarius (Namibia) and Diamantomys luederitzi (represented in both areas). After updating their systematics, morphometric analyses allowed prediction of their locomotion via the skull, humerus, ulna and femur ensuring stabilisation or increase of mobility of the limbs: the arboreals privilege the mobility of the limbs, while the terrestrials and fossorials favour stabilization. Thus, these analyses highlight specialist species, such as those of the genus Paranomalurus predicted as gliders, N. soniae arboreal and B. neotertiarius fossorial. In contrast, D. luederitzi is considered to be a generalist. The locomotor variability indicates environmental heterogeneity in Uganda and Namibia, highlighted also by the δ13C and δ18O analyses carried out on the carbonates of their dental enamel. The analysis shows an open environment with a C3-plant dominated vegetation, with the presence of woodland patches (wooded savannah) in both areas. These isotopic ratios, when coupled with those of large mammals, indicate a more humid and/or cooler environment in the Ugandan and Namibian sites than occurs in these countries today, with the Namibian being less humid and/or having a higher temperature than the East African during this period

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Sherwin, Dean. "Loessite : its occurrence, recognition and interpretation." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294930.

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Powell, Clare Lorna. "The palaeoenvironments of the Rhynie Cherts." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=186707.

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With a radiometric age of 396 ± 12 ma, the Rhynie Cherts, Grampian Region, Scotland, are the oldest unequivocal surface expression of an epithermal system in the world. Data is presented from 8 cored boreholes drilled within 100m of the Rhynie Cherts subcrop. The cherts are present in the upper part of the Lower Devonian basin infill which forms the Rhynie outlier. The basin is a half-graben structure, with a northeast/southwest trending western boundary, following the regional stress trend. In the area of the Rhynie Cherts, the western boundary is complicated by a series of cross faults. The eastern boundary is unconformable. The basin infill, in the area of Rhynie village, is a fining upwards sequence, produced locally from the newly formed Caledonide mountains. The basal Pre-Lava Sandstones Unit is an alluvial fan deposit. This is overlain by a series of basaltic andesite lavas with associated agglomerates and lapillistones. The Tuffaceous Sandstones Unit, containing both airfall and fluvially reworked tuffaceous material was deposited at the close of volcanic activity. The next unit in the series is the Shales with Thin Sandstones Unit, which contains the Rhynie and Windyfield Cherts. These two units of the post-lava sequence represent alluvial plain deposition, with evidence for sub-aerial exposure. The uppermost unit in the outlier is the Quarry Hill Sandstones unit, comprising fluvial channel sandstones. Hot spring activity occurred during the deposition of the Shales with Thin Sandstones Unit, resulting in the deposition of the Rhynie and Windyfield Cherts. A 35m cored borehole permits study of a vertical section through the chert bearing strata.

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Lewis, Mary Gwendolyn. "Diatoms as indicators of estuarine palaeoenvironments." Thesis, University of Newcastle Upon Tyne, 2001. http://hdl.handle.net/10443/565.

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The increasing interest in the use of palacoenvironmental indicators and in particular diatoms to reconstruct past changes in sea level has highlighted the need for a more precise methodology that (a) provides quantitative reconstructions, and (b) is applicable to a wide range of sedimentary environments. Despite the widespread and increasing recent interest in the use of diatoms as indicators of estuarinep alaeoenvironmentsa nd sea-levelc hange,e xisting interpretative models, basedo n simple classification of taxa into freshwater, brackish or marine forms, provide only _qualitative estimates of past conditions. Resulting palaeoenvironmental reconstructions are at best crude, offering some indication of past mean sea level height, and at worst erroneous, as they fail to consider the effect of post-mortem transport and other taphonomic processes. This study aims to address these problems for the coast of Britain by developing a more robust quantitative method for using diatoms as indicators of estuarine palaeoenvironments and sea-level change. More specifically, it aims to develop a quantitative predictive model (transfer function) that relatesd iatom assemblagec omposition to salinity, habitat, depositional environment and tidal level around the coast of Britain. This is done through the collection and analysis of a training data set of diatom assemblagesa nd environmental variables (salinity class, elevation, grain size, habitat type and sediment organic content) from 25 sites around the coast of Britain. Qualitative and quantitative relationships within the diatom assemblagesa nd between the diatom assemblagesa nd coastale nvironmentalv ariables are explored using TWINSPAN and canonical correspondencea nalysisr espectively. The key environmental variables driving diatom assemblagesin the intertidal environment are shown to be elevation, salinity and sediment particle size. Habitat type and site location also explain a significant amount of variation in the diatom data, suggestingr egional differences in diatom assemblagesn ot accounted for by geornorphological and sedimentological differences between sites. The final transfer function for inferring normalised tidal height has a root mean squared error (RMSE) of 0.26, and a squared correlation (1-2) between observed and diatom-inferred normalised tidal height of 0.61. Corresponding error estimates under cross-validation by leave-one-out are 0.34 and 0.35 for RMSEjack and rjack 2 respectively. The poor performance of the model in comparison to published regional transfer functions is concluded to be due to the mergt:i In g of data from a large number of sites over a large geographical area. Such merging - has apparently introduced a large amount of noise into the diatom / elevation relationship, and is probably related to the increased heterogeneity and interaction of sediment typeý and elevation, and to the observed regional overprint in the diatom assemblages. Analogue matching to infer Sample habitats from the diatom data performs with a success Z): rate of 59%. Further merging of the habitat types based on ecologically similarities increases the success rate to 82%. The correct scale of trade off between coverage of palaeoenvironments, fossil diatom species 4): and reduction of regionality in the modem training dataset is an issue that needs further research before this model may be applied to core material to assist in palaeoenvironmental reconstructions.

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Blondel, François. "Approvisionnement et usages du bois en Auvergne, du Second âge du Fer au Moyen Âge." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCH021/document.

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Les bois gorgés d’eau sont des découvertes rares en archéologie, du fait des conditions inhérentes à leur conservation. Quand ils nous parviennent, ils livrent de nombreuses données sur la place de ce matériau pour les populations anciennes.L’Auvergne est un contexte privilégié pour leur conservation. Des milliers de bois issus de découvertes fortuites ou de fouilles archéologiques sont datés du Néolithique à l’époque moderne, mais le corpus couvre surtout le Second âge du Fer jusqu’au Moyen Âge.La diversité des bois permet d’appréhender les différents usages selon leur destination respective. Le bon état de nombreux éléments renseigne de différentes étapes de façonnage de l’abattage de l’arbre à sa mise en œuvre.Chaque bois est détaillé spécifiquement par domaine et catégorie pour être comparé aux vestiges d’autres régions. L’approche technologique et typologique est traitée le plus exhaustivement possible.Le spectre taxonomique renseigne les pratiques de collecte et leur évolution sur un espace forestier impacté par l’homme.L’apport de la dendrochronologie renseigne les évolutions des approvisionnements, principalement pour la construction, et dégage certains traits des pratiques sylvicoles sur les peuplements forestiers exploités
Waterlogged woods are rare discoveries in archeology because of the conditions inherent in their conservation. When they reach us, they give a lot of data on the importance of this material for past populations.Auvergne is a privileged context for their conservation. Thousands of woods from fortuitous discoveries or archaeological excavations are dated from the Neolithic to the modern era, however the corpus covers mostly the Second Iron Age until the Middle Ages.The diversity of the woods enables a better understanding of different uses according to their respective destination.The state of conservation of many elements gives information about the different stages of shaping, from the felling of the tree to its implementation.Each wood is detailed specifically by field and category to be compared with the remains of other regions. The technological and typological approach is treated as exhaustively as possible.Taxonomic diversity documents collection practices and their evolution in a forest area impacted by humans.The contribution of dendrochronology informs the evolutions of supplies, mainly for the construction, and releases certain features of the silvicultural practices in the exploited forest stands

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Mitchell, Ria Louise. "Palaeoenvironmental implications of 1.1 gapaleosols." Thesis, Royal Holloway, University of London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.530782.

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Saia, Soraya Elaine Marques Gouveia. ""Reconstrução paleoambiental (vegetação e clima) no Quaternário tardio com base em estudo multi/interdisciplinar no Vale do Ribeira (sul do Estado de São Paulo)"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/64/64134/tde-04092006-151920/.

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Os locais de estudo estão situados no PETAR Parque Estadual Turístico do Alto Ribeira e PEI Parque Estadual Intervales, na região do sudeste do Brasil. A área é caracterizada pela presença de vegetação nativa de Floresta Atlântica e dois lagos naturais conhecidos por Lagoa Grande E Lagoa Vermelha, onde foram coletados três testemunhos sedimentares. Análises químicas (C, N, mineralogia), isotópicas (12C, 13C e 14C) e biológicas (palinologia) foram usadas nesse estudo para entender a história da paleovegetação da região durante o Pleistoceno tardio e o Holoceno, assim como suas relações com as mudanças climáticas. Amostras de solo foram coletadas a partir de trincheiras e tradagens em dez locais sob vegetação de floresta natural no PETAR e no PEI. Os dados isotópicos (δ13C) da matéria orgânica do solo em dois pontos do PETAR mostraram valores de δ13C mais enriquecidos ( -17,1%0 e -20,1%0) nas camadas mais profundas, indicando a presença de uma vegetação menos densa que a atual, com uma provável mistura de plantas C3, e C4, no período de ~30.000 a 16.000 anos AP, sugerindo a presença de um clima mais seco. De ~16.000 anos AP até o presente um empobrecimento isotópico significativo (até -28,3 %0) foi observado em todos os locais, indicativo de expansão da floresta, provavelmente associada à presença de um clima mais úmido que no período anterior. Os dados isotópicos (δ13C) dos solos de PEI indicam a presença de vegetação de floresta desde ~14.000 anos AP, exceto em um local (SAI) onde valores de δ13C mais enriquecidos (-21,8 %0) foram observados, relacionados provavelmente à mistura de plantas C3 e C4 e/ou à presença de uma vegetação de floresta menos densa em ~14.000 anos AP. A partir dos resultados da matéria orgânica sedimentar do testemunho da Lagoa Grande foi verificado que as condições ambientais foram relativamente estáveis durante os últimos 1000 anos, caracterizados pela presença de plantas C3, e fitoplâncton, sugerindo condições climáticas úmidas e que o lago provavelmente não se apresentou seco durante o último milênio. Condições ambientais para a Lagoa Vermelha também foram relativamente estáveis durante os últimos 4500 anos, caracterizadas pela presença significativa de plantas C3 na matéria orgânica sedimentar indicando condições climáticas úmidas. Mudanças na composição da vegetação foram registradas pela palinologia durante o período de ~1400 a 1100 anos AP, relacionadas a presença de um provável clima frio que o atual.
The study sites are in the PETAR - Parque Estadual Turístico do Alto Ribeira and PEI - Parque Estadual Intervales, in the southeastern region of Brazil. The area is characterized by the presence of the native vegetation of Atlantic forest and two natural lakes called LAgoa Grande and Lagoa Vermelha, where three sediment cores were collected. Chemical (C, N and mineralogy), isotope (12C, 13C and 14C), and biological (pollen analyses) tools were used in the study to understand the palaeovegetation history of the region during the late Pleistocene and Holocene and its relation to climate changes. Soils samples were collected from trenches and by drilling at five locations under natural forest vegetation in the PETAR and PEI study sites.The isotope data (δ13C)collected in soil at two locations in the PETAR area showed much more enriched δ13C values ( -17,1%0 and -20,1%0)in the deeper horizons, indicating the presence of a less dense vegetation than the present modern day, with a probable mixture of C3 and C4 plants, in the period of ~30.000 to ~16.000 years BP. This pattern suggested the presence of a drier climate. From ~16.000 years BP to the present, a significant isotopic depletion (up to -28,3 %0)was observed in all sites indicating an expansion of the forest, probable associated to the presence of a more humid climate than the previous period. The isotope results (δ13C) collected at the PEI soils indicated the presence of forest vegetation since ~14.000 years BP, except in one location (SAI), where more enriched δ13C values (-21,8 %0) were observed probable related to mixture of C3 e C4 plants, and/or a presence of a less dense forest vegetation around ~14.000 years BP. From the results of the sediment organic matter compositions of LAgoa Grande, it was verified that the environmental conditions were relatively stable during the last 1000 years, characterized by the presence of C3 plants and phytoplankton, suggesting humid climaticconditions and the lake probable wasn't dry during the last millennium. Environmental conditions for the Lagoa Vermelha were also relatively stable during the last 4500 years, characterized by the significant presence of C3 plants in the sediment organic matter indicating humid climatic conditions. The changes in vegetation composition recorded by palynology during the period of ~1400 to 1100 years BP can be related to existence of a probable colder climate than today.

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Mehrshahi, Daryoush. "Late Quaternary palaeoenvironments, Ardakan Playa, central Iran." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301016.

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Hill, Alan Frederick Mark. "The sulphur geochemistry of Jurassic source rocks." Thesis, University of Aberdeen, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283752.

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In immature Jurassic shales of differing depositional environment from Great Britain (Ro<0.5) the C₃₂ hopane and C₂₉ sterane isomerisation provide an accurate indication of relative maturities. For mature Viking Graben samples (Ro>0.7) a reliable indication of relative maturity is gained if Tmax, Ts(Ts+Tm), C₂₉ββ/(ββ+αα) steranes and the Triaromatic Index are considered together. The most reliable parameters for the determination of depositional redox are pristane/phytane and the C₃₅/C₃₄ homohopane ratio, together with the concentrations of V, Cu, Ni and Mo. In the brackish lagoon of the Brora Coal Formation (BCF) low sulphate availability does not appear to have limited the pyritisation of iron relative to the open marine facies of the Brora Argillaceous Formation (BAF). Despite this δ³⁴Spyrite for BCF samples indicates that sulphate reduction took place in a closed system due to the rapid depletion of available sulphate. Only low concentrations of excess H₂S were available for incorporation within the organic matter, organic sulphur abundances in the BCF being much lower than for the BAF. In open-marine sequences an increase in TOC is associated with an increase in anoxia, the preservation of hydrogen-rich organic matter and the abundance of organic sulphur. A generally correlated increase in pyrite sulphur suggests both these modes of sulphur are associated with increasing concentrations of diagenetic sulphides (H₂S and its partial oxidation products) generated through bacterial sulphate reduction. The greatest abundances of organic sulphur are formed when sulphide concentrations are high whilst sub-oxic surficial sediments are maintained so that polysulphides are generated within the sediment (by partial oxidation of H₂S) for rapid sulphur incorporation. Improved preservation of labile organic matter leads to a increase in the abundance of organic compounds (e.g. sterenes and phytol derivatives) in which suitable functionalities exist for sulphur incorporation.

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Dissertations / Theses on the topic 'Palaeoenvironment'

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