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1
Vanbuskirk, Stephanie. "Alluvial stratigraphy and soil formation at Cox Ranch Pueblo, New Mexico". Online access for everyone, 2004. http://www.dissertations.wsu.edu/Thesis/Fall2004/s%5Fvanbuskirk%5F120904.pdf.
Testo completo
2
Metcalfe, Elisabet Joan. "Late-glacial through Holocene Stratigraphy and Lake-level Record of Rangely Lake, Western Maine". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/MetcalfeEJ2007.pdf.
Testo completo
3
Robinson, Stuart Alan. "Carbon-cycling, palaeo-atmospheres and isotope stratigraphy of marginal and non-marine Mesozoic sediments". Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269481.
Testo completo
4
Jansson, Anna. "Stratigraphy, Landscape Evolution, and Past Environments at the Billy Big Spring Site, Montana". Thesis, The University of Arizona, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10643050.
Testo completoAbstract (sommario):
This thesis reconstructs the landscape evolution of the Billy Big Spring site (24GL304, Glacier County, north-central Montana) from the last glacial maximum to present through the analysis of sediment and soil samples collected from a transect of auger tests that bisected the site and surrounding landforms. Interpretations were drawn from stratigraphy, pedologic data, sedimentologic analysis and radiocarbon dating. The site landscape came into being in the late-Pleistocene, after Wisconsin-age glaciers retreated. Glacial retreat left a meltdown depression on the land that filled with water to form a pond, which persisted through the early-Holocene. The onset of the mid-Holocene (Altithermal) occurred before ~8,415 cal. yrs. BP, when increasingly arid conditions caused the water level to drop. The first radiocarbon dated human occupation of this site occurred during the Altithermal, ~7,030 cal. yrs. BP, after the eruption of Mount Mazama (~7,633 cal. yrs. BP). Arid conditions continued until ~7,000 cal. yrs. BP, when pond water re-expanded across the basin, marking the transition to the cooler late-Holocene. Sometime before 2,100 cal. yrs. BP, dry conditions returned, and the extent of the pond water decreased again. Since this time, overland alluvial processes have deposited sediments in the basin. Many hypotheses on how the Altithermal impacted the people of the Northwestern Plains have been proposed since the 1950s, but little agreement has been reached. This is due to the fact that there was great variation in how the Altithermal expressed itself throughout the Northwestern Plains. The human reactions to this phenomena cannot be explained simplistically for the region as a whole. This study shows that the Billy Big Spring site experienced drying during the Altithermal, but despite this, people continued to occupy this site. This evidence adds to the argument that the Altithermal climate of the Northwestern Plains did not have severe enough impacts to impose much hardship on its occupants.
5
Chu, Lap-man Raymond. "Material identification and subsurface stratigraphy of Penny's Bay reclamation site : by the method of subsurface exploration : piezocone penetration test and drilling /". Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576660.
Testo completo
6
Davis, Karen Melissa. "Using Apparent Electrical Conductivity (ECa) via Electromagnetic Induction (EMI) to Characterize Soils and the Stratigraphy for Wetland Restoration". NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-04302007-204731/.
Testo completoAbstract (sommario):
Wetland restoration can be difficult due to the time consuming efforts it requires to evaluate the soils and vegetation within the area being considered. The objective of this study was to determine whether apparent soil electrical conductivity (ECa) measured via electromagnetic induction (EMI) (a non-contact method) could be used to identify soil particle size distribution, map units, and selected chemical properties at a Carolina bay wetland restoration site, Juniper Bay. Surveys of ECa were performed at Juniper Bay in December 2000, June 2001, October 2005, and December 2005 using the EM38, GEM-2, and GEM-300 in the horizontal and vertical dipole positions. Cores were dug to depths of 6.1 and 15.2 m based on an equilateral triangle grid and adequate representative sampling of soil map units. Pits were dug to 1- and 1.5-m depths. Core and pit samples were analyzed for particle size distribution and soil chemical properties. Surficial samples were collected from 0- to 15-cm and 15- to 30-cm depths; chemical properties were evaluated on these samples. Correlations of ECa with soil particle size distribution and chemical properties were determined. Linear models were derived relating soil clay content and ECa. Soil ECa was compared with soil organic C and water table depth to determine if either property could be detected using EMI. Also, ECa from different survey dates were compared to determine whether there were short-term (within a day) and long-term (months to years) temporal changes in ECa. The ECa from the initial overall December 2000 survey was strongly correlated with soil core clay content at depths from 0.61 to 1.22 m and 2.74 to 3.96 m. The reason for this is unknown. Initial overall December 2000 ECa was also strongly correlated with pit clay content. No other soil core or pit particle size analysis properties had strong significant and consistent correlations with ECa for the December 2000 survey or for any of the other surveys. Few chemical properties were correlated with ECa; however, ECa was weakly correlated with pit organic C. Results showed that ECa could not be used to delineate soil map unit, but the map unit ECa means were different. However, ECa could not detect water table depth at Juniper Bay. Soil ECa was found to be temporally variable, and ECa surveyors should be conscious of potentially varying conditions from survey to survey. Along with ground-truthing, ECa modeling could be used to estimate clay content at certain depths and locations within Juniper Bay. This could aid wetland restoration by identifying locations of aquitards, which might have been penetrated by drainage ditches. Filling the ditches in the correct places could allow restoration to progress faster and more efficiently.
7
Arey, Jordan Vincent. "Stratigraphy and Soils of Fluvial Terraces on the Catawba River, NC and SC| Landscape Evolution of the Southeastern US". Thesis, The University of North Carolina at Charlotte, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10814283.
Testo completoAbstract (sommario):
Few studies provide data that can document the long-term landscape evolution of the Piedmont of the southeastern United States. Here we present the results of field mapping and a soil chronosequence for fluvial terraces along a ~46 km reach of the Catawba River, NC and SC. Five terrace units (Qt1–5) have been mapped along the reach, and in certain regions a sixth surface (Qt0) was mapped. Observations of bedrock surfaces on Qt3–Qt0 confirmed that these units are strath terraces. Longitudinal profiles of terrace units constructed from mapping data revealed static channel convexities in Qt5–Qt1 in the lower reach of the study area at Landsford Canal State Park, and a lack of an obvious influence on terraces profiles within the Gold and Silver Hill shear zones in the middle reach. Age dating of terraces in this study included deriving ages based on surface height above the channel (Mills, 2000) and IRSL samples obtained from Qt3 exposures. Ages, reported in ka, are as follows: Qt0—4591 ± 404 ka, Qt1—1852 ± 365 ka, Qt2—1181 ± 194 ka, Qt3 (average of two IRSL ages)—142 ± 32 ka, Qt4—50 ± 8 ka, and Qt5—5 ± 2 ka. Up to 3 soil pits were dug on each terrace unit Qt5—Qt2, and soils described as per Birkeland (1999). Chronofunction trends of soil morphological properties include soil colors in the most developed B horizons reddening and clay films increasing in amount and prominence with surface age. Soil samples were analyzed for particle size, pedogenic iron (AAS), bulk density and major elements (XRF). Some of these analyses show expected trends with respect increasing surface age for terraces of the Catawba River, such as increases in clay content (%) and decreases in iron activity ratios in most weathered B horizons with increasing surface age. Overall the history Catawba River is one of five distinct periods of lateral planation of the valley, possibly driven by transitions to interglacial periods, punctuated by periods of incision, whose cause is currently unknown. The soil chronosequence, ages, and data derived from mapping, however, provide a strong foundation that can be used in further studies of the long-term landscape evolution of the SE Piedmont of the SE United States.
8
Chu, Lap-man Raymond, e 朱立民. "Material identification and subsurface stratigraphy of Penny's Bay reclamation site: by the method of subsurfaceexploration : piezocone penetration test and drilling". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42576660.
Testo completo
9
Mayer, James H. "Late Quaternary Landscape Evolution, Environmental Change, and Paleoindian Geoarchaeology in Middle Park, Colorado". Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/193994.
Testo completoAbstract (sommario):
Stratigraphic records in Middle Park in north-central Colorado provide evidence for the late Quaternary geomorphic and environmental history of a non-glaciated Southern Rocky Mountain basin. Episodes of geomorphic instability apparent in the stratigraphic record coincide with changes in paleoenvironmental records from above 2750 m in north-central Colorado, suggesting that the western Middle Park landscape was sensitive to environmental changes affecting the region over the last ~14,000 years. Tributaries were incised prior to 14.0 ka, but deposits older than 12.0 ka are rare. Upland erosion and incision followed by rapid aggradation in alluvial settings between 12.0 and 11.0 ka coincide with evidence for regional temperatures at or above present, and is interpreted to signal the onset of Holocene summer-wet precipitation. A widespread soil-stratigraphic marker represents a long period of landscape stability between <11.0 and 6.0 ka in upland and alluvial settings. Pedologic evidence from upland settings indicates the expansion of grass and forest cover to lower elevations that today are characterized by sagebrush steppe, probably during a period of increased summer precipitation relative to present. During the late Holocene, episodes of aggradation in alluvial valleys at 6.0-1.0 ka and 0.6-0.2 ka and soil formation in uplands at 5.0-3.5 ka and 2.5-1.0 ka overlap with evidence for cooling at higher elevations. Incision of valley floors documented at 1.0-0.6 ka and during the last few centuries and episodes of erosion in uplands at 3.5-2.5 ka, after 1.0 ka, and within the last few centuries, are roughly synchronous with evidence for warming. Upland and alluvial stratigraphic records are interpreted to indicate that during cool intervals summer precipitation was diminished, resulting in relative hillslope stability and gradual valley bottom aggradation, while pulses in summer precipitation accompanying warmer episodes caused basin-wide geomorphic instability. The recent increasing frequency of geomorphic instability appears to correspond with an increase in sagebrush steppe at the expense of forest and grass cover, interpreted to represent progressive drying during the late Holocene. It stands to reason that future warming, if accompanied by similar patterns in precipitation, will result in continued erosion on a landscape already at a threshold of geomorphic instability.
10
Almond, Peter C. "Soils and geomorphology of a lowland rimu forest managed for sustainable timber production". Lincoln University, 1997. http://hdl.handle.net/10182/1782.
Testo completoAbstract (sommario):
Saltwater Forest is a Dacrydium cupressinum-dominated lowland forest covering 9000 ha in south Westland, South Island, New Zealand. Four thousand hectares is managed for sustainable production of indigenous timber. The aim of this study was to provide an integrated analysis of soils, soil-landform relationships, and soil-vegetation relationships at broad and detailed scales. The broad scale understandings provide a framework in which existing or future studies can be placed and the detailed studies elucidate sources of soil and forest variability. Glacial landforms dominate. They include late Pleistocene lateral, terminal and ablation moraines, and outwash aggradation and degradation terraces. Deposits and landforms from six glacial advances have been recognised ranging from latest Last (Otira) Glaciation to Penultimate (Waimea) Glaciation. The absolute ages of landforms were established by analysis of the thickness and soil stratigraphy of loess coverbeds, augmented with radiocarbon dating and phytolith and pollen analysis. In the prevailing high rainfall of Westland soil formation is rapid. The rate of loess accretion in Saltwater Forest (ca. 30 mm ka⁻¹) has been low enough that soil formation and loess accretion took place contemporaneously. Soils formed in this manner are known as upbuilding soils. The significant difference between upbuilding pedogenesis and pedogenesis in a topdown sense into an existing sediment body is that each subsoil increment of an upbuilding soil has experienced processes of all horizons above. In Saltwater Forest subsoils of upbuilding soils are strongly altered because they have experienced the extremely acid environment of the soil surface at some earlier time. Some soil chronosequence studies in Westland have included upbuilding soils formed in loess as the older members of the sequence. Rates and types of processes inferred from these soils should be reviewed because upbuilding is a different pedogenic pathway to topdown pedogenesis. Landform age and morphology were used as a primary stratification for a study of the soil pattern and nature of soil variability in the 4000 ha production area of Saltwater Forest. The age of landforms (> 14 ka) and rapid soil formation mean that soils are uniformly strongly weathered and leached. Soils include Humic Organic Soils, Perch-gley Podzols, Acid Gley Soils, Allophanic Brown Soils, and Orthic or Pan Podzols. The major influence on the nature of soils is site hydrology which is determined by macroscale features of landforms (slope, relief, drainage density), mesoscale effects related to position on landforms, and microscale influences determined by microtopography and individual tree effects. Much of the soil variability arises at microscales so that it is not possible to map areas of uniform soils at practical map scales. The distribution of soil variability across spatial scales, in relation to the intensity of forest management, dictates that it is most appropriate to map soil complexes with boundaries coinciding with landforms. Disturbance of canopy trees is an important agent in forest dynamics. The frequency of forest disturbance in the production area of Saltwater Forest varies in a systematic way among landforms in accord with changes in abundance of different soils. The frequency of forest turnover is highest on landforms with the greatest abundance of extremely poorly-drained Organic Soils. As the abundance of better-drained soils increases the frequency of forest turnover declines. Changes in turnover frequency are reflected in the mean size and density of canopy trees (Dacrydium cupressinum) among landforms. Terrace and ablation moraine landforms with the greatest abundance of extremely poorly-drained soils have on average the smallest trees growing most densely. The steep lateral moraines, characterised by well drained soils, have fewer, larger trees. The changes manifested at the landform scale are an integration of processes operating over much shorter range as a result of short-range soil variability. The systematic changes in forest structure and turnover frequency among landforms and soils have important implications for sustainable forest management.
11
Robertson-Rintoul, Melanie S. E. "River planform, soil stratigraphy and the temporal and palaeoenvironmental significance of terraced valley fill deposits in upland Scotland, with specific reference to Glen Feshie, south-west Cairngorms". Thesis, University of Hull, 1986. http://hydra.hull.ac.uk/resources/hull:13132.
Testo completoAbstract (sommario):
River terraces form prominent features of the valley floor morphology of many upland valleys in Scotland. Little is known, however, about valley floor landform development in many of these valleys. Previous studies have generally explained the terraces as the outwash products of meltwaters from the most recent cold periods. Detailed investigation of a major valley in the Scottish Highlands challenges, for at least one site, this well established concept and proposes the occurrence of at least three phases of Holocene terrace development. The correlation of terrace surfaces has traditionally been based upon the construction of height-range diagrams. An alternative approach to terrace correlation and dating is developed in this study using data from Glen Feshie, south-west Cairngorms. Terrace fragments are numerically classified and objectively grouped using quantitative soil-stratigraphic data. Principal Components Analysis and a hierarchical clustering technique numerically define five soil-stratigraphic units and place these on a relative time scale. Various methods of absolute dating control permit association of these units with five phases of terrace development. These are placed at 13,000, 10,000, 3,600, 1,000, 80, radiocarbon years BP. Comparison of palaeochannel networks preserved on the terrace surfaces suggests that these phases of terrace development have been associated with changes in channel pattern morphology. A unified approach to analysis of channel pattern morphology is developed and from this a new technique for palaeohydrological interpretation of gravel-bed streams. A segment density index is developed which allows total sinuosity to be predicted from just a part of the braided channel network. Application of these techniques to the Glen Feshie terraces demonstrates a trend for an overall decrease in discharge from the oldest terrace surfaces to the present day. Assessment of these landform changes within the context of known environmental fluctuations in the Cairngorms suggests that the early-mid Holocene was a period of relative landscape stability while the late Holocene was characterised by increasing instability. These changes may have been associated with the changes in river behaviour. However, spatial variation in the depth of the fill/bedrock interface may produce a discontinuous river response to changing environmental conditions.
12
Papagiannis, Michail. "WIND TURBINE FOUNDATIONS IN CLAY : Technical and economic considerations for proposals for wind turbine foundations". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-353397.
Testo completoAbstract (sommario):
This thesis approaches the problem of the cost-efficient wind turbine foundation on an onshore site of clayey soil characteristics. The given soil stratigraphy includes a layer of clay and two sands of different density. The characteristics of the soil and the water level that were used as input come from a site in Peloponissos, Greece. The applied wind, static and seismic loads on this study were resolved with the German DIN standards, and other related research and European standards. The safety factors were adjusted for wind turbines. For the pile solution, after the bearing and overturning adequacy against the horizontal and vertical loads was proven with the calculation of the DIN equations, then the model was inserted in the Pfahl program using DIN 4017 equations to calculate settlements. Firstly, a shallow foundation of various dimensions in the clay layer over the water level with all the necessary checks was considered. Afterward, a deep foundation solution of a single bored pile, with reinforcement steel casing, of various diameters was investigated. The different foundation solutions were assessed and compared on a technical and economic basis. As a conclusion, the 0.70 meter diameter single pile was chosen as the best solution because it needs only a few days for construction, and it is the most cost-efficient. The chosen circular footing was of a diameter of 10 meters and 1.5 meter raft thickness, but proved unfeasible because of high excavations costs. The checks on the DIN standards and Eurocode that set the boundaries for the design in the two cases were recognised and possible future work goals were discussed.
13
Anne, Cheikh Amadou Tidiane [Verfasser], Jürgen [Akademischer Betreuer] Runge e Jürgen [Akademischer Betreuer] Wunderlich. "Stratigraphy and properties of soil profiles along transects in Burkina Faso and Benin and their influence on phytodiversity / Cheikh Amadou Tidiane Anne. Gutachter: Jürgen Runge ; Jürgen Wunderlich. Betreuer: Jürgen Runge". Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2013. http://d-nb.info/1045005185/34.
Testo completo
14
Hughes, Matthew William. "Late Quaternary Landscape Evolution and Environmental Change in Charwell Basin, South Island, New Zealand". Phd thesis, Lincoln University. Agriculture and Life Sciences Division, 2008. http://theses.lincoln.ac.nz/public/adt-NZLIU20080214.132530/.
Testo completoAbstract (sommario):
Charwell Basin is a 6 km-wide structural depression situated at the boundary between the axial ranges and faulted and folded Marlborough Fault Zone of north-eastern South Island, New Zealand. The basin contains the piedmont reach of the Charwell River, and a series of late Quaternary loess-mantled alluvial terraces and terrace remnants that have been uplifted and translocated from their sediment source due to strike-slip motion along the Hope Fault which bounds the basin to its immediate north. The aim of this study was to provide an interdisciplinary, integrated and holistic analysis of late Quaternary landscape evolution and environmental change in Charwell Basin using terrain analysis, loess stratigraphy, soil chemistry and paleoecological data. The study contributes new understanding of New Zealand landscape and ecosystem responses to regional and global climatic change extending to Marine Isotope Stage (MIS) 6, and shows that climatically-forced shifts in biogeomorphic processes play a significant role in lowland landscape evolution.
Morphometric analysis of alluvial terraces and terrace remnants of increasing age demonstrated geomorphic evolution through time, with a decrease in extent of original planar terrace tread morphology and an increase in frequency of steeper slopes and convexo-concave land elements. Paleotopographic analysis of a >150 ka terrace mantled by up to three loess sheets revealed multiple episodes of alluvial aggradation and degradation and, subsequent to river abandonment, gully incision prior to and coeval with loess accumulation. Spatial heterogeneity in loess sheet preservation showed a complex history of loess accumulation and erosion. A critical profile curvature range of -0.005 to -0.014 (d2z/dx2, m-1) for loess erosion derived from a model parameterised in different ways successfully predicted loess occurrence on adjacent slope elements, but incorrectly predicted loess occurrence on an older terrace remnant from which all loess has been eroded. Future analyses incorporating planform curvature, regolith erosivity and other landform parameters may improve identification of thresholds controlling loess occurrence in Charwell Basin and in other South Island landscapes.
A loess chronostratigraphic framework was developed for, and pedogenic phases identified in, the three loess sheets mantling the >150 ka terrace. Except for one age, infrared-stimulated luminescence dates from both an upbuilding interfluve loess exposure and colluvial gully infill underestimated loess age with respect to the widespread Kawakawa/Oruanui Tephra (KOT; 27,097 ± 957 cal. yr BP), highlighting the need for improvements in the methodology. Onset of loess sheet 1 accumulation started at ca. 50 ka, with a break at ca. 27 ka corresponding to the extended Last Glacial Maximum (eLGM) interstadial identified elsewhere in New Zealand. Loess accumulation through MIS 3 indicates a regional loess flux, and that glaciation was not a necessary condition for loess generation in South Island. Loess accumulation and local alluvial aggradation are decoupled: the youngest aggradation event only covers ~12 kyr of the period of loess sheet 1 accumulation. Older local aggradation episodes could not be the source because their associated terraces are mantled by loess sheet 1. In the absence of numerical ages, the timing of L2 and L3 accumulation is inferred on the basis of an offshore clastic sediment record. The upbuilding phase of loess sheet 2 occurred in late MIS 5a/MIS 4, and loess sheet 3 accumulated in two phases in MIS 5b and late MIS 6.
Biogenic silica data were used to reconstruct broad shifts in vegetation and changes in gully soil saturation status. During interglacial/interstadial periods (MIS 1, early MIS 3, MIS 5) Nothofagus¬-dominated forest covered the area in association with Microlaena spp grasses. Lowering of treeline altitude during glacial/stadial periods (MIS 2, MIS 3, MIS 5b, late MIS 6) led to reduction in forest cover and a mosaic of shrubs and Chionochloa spp, Festuca spp and Poa spp tussock grasses. Comparison of interfluve and gully records showed spatial heterogeneity in vegetation cover possibly related to environmental gradients of exposure or soil moisture. A post-KOT peak in gully tree phytoliths corresponds to the eLGM interstadial, and a shift to grass-dominated vegetation occurred during the LGM sensu stricto. Diatoms indicated the site became considerably wetter from ca. 36 ka, with peak wetness at ca. 30, 25 and 21 ka, possibly due to reduced evapotranspiration and/or increased precipitation from a combination of strengthened westerly winds and increased cloudiness, or strengthened southerly flow and increased precipitation. Human influence after ca. 750 yr BP led to re-establishment of grassland in the area, which deposited phytoliths mixed to 30 cm depth in the soil.
A coupled gully colluvial infilling/vegetation record showed that sediment flux during the late Pleistocene was ~0.0019 m3 m-1 yr-1 under a shrubland/grassland mosaic, and Holocene sediment flux was ~0.0034 m3 m-1 yr-1 under forest. This increase of 60% through the last glacial-interglacial transition resulted from increased bioturbation and down-slope soil transport via root growth and treethrow, which formed a biomantle as evidenced by slope redistribution of the KOT. These results contrast with sediment transport rates and processes hypothesised to occur contemporaneously in adjacent mountain catchments. This suggests that intraregional biogeomorphic processes can differ significantly depending on topography and geological substrate, with different landscapes responding in unique ways to the same climate shifts. Analysis of Quaternary terrestrial landscape evolution in non-glaciated mountainous and lowland areas must therefore consider spatial and temporal heterogeneity in sediment fluxes and underlying transport processes.
15
Hughes, Matthew W. "Late Quaternary landscape evolution and environmental change in Charwell Basin, South Island, New Zealand". Lincoln University, 2008. http://hdl.handle.net/10182/305.
Testo completoAbstract (sommario):
Charwell Basin is a 6 km-wide structural depression situated at the boundary between the axial ranges and faulted and folded Marlborough Fault Zone of north-eastern South Island, New Zealand. The basin contains the piedmont reach of the Charwell River, and a series of late Quaternary loess-mantled alluvial terraces and terrace remnants that have been uplifted and translocated from their sediment source due to strike-slip motion along the Hope Fault which bounds the basin to its immediate north. The aim of this study was to provide an interdisciplinary, integrated and holistic analysis of late Quaternary landscape evolution and environmental change in Charwell Basin using terrain analysis, loess stratigraphy, soil chemistry and paleoecological data. The study contributes new understanding of New Zealand landscape and ecosystem responses to regional and global climatic change extending to Marine Isotope Stage (MIS) 6, and shows that climatically-forced shifts in biogeomorphic processes play a significant role in lowland landscape evolution. Morphometric analysis of alluvial terraces and terrace remnants of increasing age demonstrated geomorphic evolution through time, with a decrease in extent of original planar terrace tread morphology and an increase in frequency of steeper slopes and convexo-concave land elements. Paleotopographic analysis of a >150 ka terrace mantled by up to three loess sheets revealed multiple episodes of alluvial aggradation and degradation and, subsequent to river abandonment, gully incision prior to and coeval with loess accumulation. Spatial heterogeneity in loess sheet preservation showed a complex history of loess accumulation and erosion. A critical profile curvature range of -0.005 to -0.014 (d²z/dx², m⁻¹) for loess erosion derived from a model parameterised in different ways successfully predicted loess occurrence on adjacent slope elements, but incorrectly predicted loess occurrence on an older terrace remnant from which all loess has been eroded. Future analyses incorporating planform curvature, regolith erosivity and other landform parameters may improve identification of thresholds controlling loess occurrence in Charwell Basin and in other South Island landscapes. A loess chronostratigraphic framework was developed for, and pedogenic phases identified in, the three loess sheets mantling the >150 ka terrace. Except for one age, infrared-stimulated luminescence dates from both an upbuilding interfluve loess exposure and colluvial gully infill underestimated loess age with respect to the widespread Kawakawa/Oruanui Tephra (KOT; 27,097 ± 957 cal. yr BP), highlighting the need for improvements in the methodology. Onset of loess sheet 1 accumulation started at ca. 50 ka, with a break at ca. 27 ka corresponding to the extended Last Glacial Maximum (eLGM) interstadial identified elsewhere in New Zealand. Loess accumulation through MIS 3 indicates a regional loess flux, and that glaciation was not a necessary condition for loess generation in South Island. Loess accumulation and local alluvial aggradation are decoupled: the youngest aggradation event only covers ~12 kyr of the period of loess sheet 1 accumulation. Older local aggradation episodes could not be the source because their associated terraces are mantled by loess sheet 1. In the absence of numerical ages, the timing of L2 and L3 accumulation is inferred on the basis of an offshore clastic sediment record. The upbuilding phase of loess sheet 2 occurred in late MIS 5a/MIS 4, and loess sheet 3 accumulated in two phases in MIS 5b and late MIS 6. Biogenic silica data were used to reconstruct broad shifts in vegetation and changes in gully soil saturation status. During interglacial/interstadial periods (MIS 1, early MIS 3, MIS 5) Nothofagus-dominated forest covered the area in association with Microlaena spp grasses. Lowering of treeline altitude during glacial/stadial periods (MIS 2, MIS 3, MIS 5b, late MIS 6) led to reduction in forest cover and a mosaic of shrubs and Chionochloa spp, Festuca spp and Poa spp tussock grasses. Comparison of interfluve and gully records showed spatial heterogeneity in vegetation cover possibly related to environmental gradients of exposure or soil moisture. A post-KOT peak in gully tree phytoliths corresponds to the eLGM interstadial, and a shift to grass-dominated vegetation occurred during the LGM sensu stricto. Diatoms indicated the site became considerably wetter from ca. 36 ka, with peak wetness at ca. 30, 25 and 21 ka, possibly due to reduced evapotranspiration and/or increased precipitation from a combination of strengthened westerly winds and increased cloudiness, or strengthened southerly flow and increased precipitation. Human influence after ca. 750 yr BP led to re-establishment of grassland in the area, which deposited phytoliths mixed to 30 cm depth in the soil. A coupled gully colluvial infilling/vegetation record showed that sediment flux during the late Pleistocene was ~0.0019 m³ m⁻¹ yr⁻¹ under a shrubland/grassland mosaic, and Holocene sediment flux was ~0.0034 m³ m⁻¹ yr⁻¹ under forest. This increase of 60% through the last glacial-interglacial transition resulted from increased bioturbation and down-slope soil transport via root growth and treethrow, which formed a biomantle as evidenced by slope redistribution of the KOT. These results contrast with sediment transport rates and processes hypothesised to occur contemporaneously in adjacent mountain catchments. This suggests that intraregional biogeomorphic processes can differ significantly depending on topography and geological substrate, with different landscapes responding in unique ways to the same climate shifts. Analysis of Quaternary terrestrial landscape evolution in non-glaciated mountainous and lowland areas must therefore consider spatial and temporal heterogeneity in sediment fluxes and underlying transport processes.
16
Yang, Chien-Tai. "Boundary condition and inherent stratigraphic effects on microstructure evolution in sand specimens". Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/20213.
Testo completo
17
Abbott, James T. "Late Quaternary alluviation and soil erosion in Southern Italy /". Digital version accessible at:, 1997. http://wwwlib.umi.com/cr/utexas/main.
Testo completo
18
Bélanger, Julie. "Analyse de stabilité des pentes rocheuses de la mine Troilus, Chibougamau, Qc. /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.
Testo completo
19
Webb, Laura D. "Historical changes in the geomorphology of the Ottawa River (NW Ohio, U.S.A.) due to urbanization and land clearance". Bowling Green State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1276534992.
Testo completo
20
Hegazy, Yasser Ali. "Delineating geostratigraphy by cluster analysis of piezocone data". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/20506.
Testo completo
21
Dilley, Thomas Edward 1959. "Late Quaternary loess stratigraphy, soils, and environments of the Shaw Creek Flats Paleoindian sites, Tanana Valley, Alaska". Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282635.
Testo completoAbstract (sommario):
The late Quaternary stratigraphy of three Paleoindian archaeological sites, located on the edge of Shaw Creek Flats in the middle Tanana Valley, Alaska, consist of up to 2 meters of calcareous eolian sand, loess, and buried paleosols. Two Paleoindian occupations at the Broken Mammoth, Swan Point, and Mead sites date from 11,800 to 11,000 yr B.P. and from 10,800 to 9500 yr B.P. Well-preserved faunal remains, worked mammoth ivory, stone and organic tools, and at Swan Point, the early occurrence of microblades dating to 11,700 yr B.P., are associated with buried paleosols at the base of the loess. Stratigraphic and radiocarbon-chronological correlations between the sites, and at similar geological sections, suggest the presence of a regionally-correlative, eolian stratigraphy consisting of three main units: (1) a basal gray eolian sand, overlying a deflated, ventifacted, bedrock surface, was deposited as bluff-top sand sheets probably during the Birch Period transition from periglacial steppe-tundra environments to shrub tundra about 12,000 to 14,000 yr B.P. (2) An overlying lower loess unit contains three paleosol complexes, classified as Typic Cryorthents, which consist of a series of cumulative Abk horizons overlying Ck loess parent material. The lower paleosol complex dates to 11,800 to 11,000 yr B.P. as is associated with the initial occupation of the sites. The middle paleosol complex dates from 10,800 to about 9500 yr B.P. and is associated with the second Paleoindian occupation. The upper paleosol complex is weakly developed, contains no cultural material, and reflects an increase in loess deposition rates. Abundant pedogenic carbonate features indicate dry, warm, alkaline soil conditions. Faunal remains, soil characteristics, and regional palynological studies indicate a warm, dry, open parkland of poplar-willow scrub forest during the deposition of the lower loess, paleosol formation, and Paleoindian occupations. (3) An upper loess unit, up to a meter thick, lacks paleosols, has been leached of carbonate, and has a late Holocene Alfic Cryochrept soil developed on its upper surface. Rapid, coarse-grained loess deposition occurred from about 9000 to 6000 yr B.P. By 4500 yr B.P., slow, fine-grained loess deposition began under boreal forest conditions and continues today.
22
Anderson, Noel P. "The use of soil characterization information in the correlation of Wisconsinan-age glacial drift in Randolph County, Indiana". Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/544001.
Testo completoAbstract (sommario):
The upland soils of Randolph County, Indiana were studied for the following purposes: to provide an additional characterization of these soils, to identify a set of soil parameters that could delineate the extent of Late Wisconsinan glaciation in that county and to determine if there were any geographic trends in silt cap thickness. The study was prompted from observations by the recent Randolph County Soil Survey team that high clay content soils commonly associated with the county's Late Wisconsinan till (Lagro Formation) were found south of its previously mapped boundary.The only soil parameters that were effective in mapping the extent of Late Wisconsinan glaciation were: particle size analyses and some combinations of particle size analysis data with other soil parameters. The data support the previously mapped boundary of the Late Wisconsinan sediments in Randolph County, Indiana.Silt cap thickness was identified to be greatest in three areas of the county. However, the source(s) of these silts could not be determined.Department of Geology
23
Sophady, Heng. "Archaeo-stratigraphy of Laang Spean prehistoric site (Battambang Province) : a contribution to Cambodian Prehistory". Thesis, Paris, Muséum national d'histoire naturelle, 2016. http://www.theses.fr/2016MNHN0025.
Testo completoAbstract (sommario):
Laang Spean est la plus grande grotte préhistorique du nord-ouest du Cambodge, située au sud-ouest de la province de Battambang à environ 330 km de Phnom Penh. Nichée au sommet de la colline calcaire de Phnom Teak Trang, cette grotte a été découverte et fouillée dans les années 1960 par Cécile et Roland Mourer puis reprise en 2009 par la Mission préhistorique franco-cambodgienne (MNHN, Paris et le Ministère de la Culture du Cambodge). Les découvertes obtenues entre 2009 et 2015 constituent le matériel d’étude de cette thèse et ont permis d’enrichir la séquence archéologique connue sur une puissance stratigraphique de 5 mètres de profondeur. Les horizons culturels comprennent des artefacts lithiques (galets et silex), de la poterie, des os d'animaux et des sépultures humaines. Le résultat principal repose sur la mise en évidence de trois couches distinctes d'occupation comprise entre 71000 BP à 3000 BP : Néolithique, Hoabinhien, pré-hoabinhien. Un nouveau cadre chrono-culturel a été obtenu en croisant des méthodes modernes de datation (14C-AMS, OSL, U-Th et fraction minérale). Nous avons pu ainsi discuter de l'occupation Hoabinhienne (derniers chasseurs-cueilleurs du Sud-Est asiatique) et la replacer à la transition pléistocène-holocène. Antérieur au niveau Hoabinhien (11 à 71ka), une autre occupation de chasseurs-cueilleurs a été enregistrée avec des restes de faune et des éclats de silex, qui conduit à nous interroger sur la succession des activités humaines préhistoriques avant l’Holocène dans cette région calcaire du nord- ouest du Cambodge. Les résultats chronologiques et archéo-stratigraphiques nous permettent à présent de mieux comprendre la position du techno-complexe Hoabinhien dans son cadre culturel, environnemental et spatial à des fins de comparaisons futures avec d’autres sites de chasseurs-cueilleurs d’Asie du Sud-Est continentale. Enfin, l’étude du site de Laang Spean met en parallèle deux modèle inédits d’occupation ancienne et d’exploitation du territoire : un campement pour les chasseurs Hoabinhiens et une nécropole pour les gens du NéolithiqueLaang Spean is the biggest prehistoric cave situated near the top of the limestone mountain known as Phnom Teak Treang, southwest of Battambang province, northwest of Cambodia, and approximately 330 km from Phnom Penh. The cave was discovered and initially excavated by Cécile and Roland Mourer in the 1960s. Since 2009, the site has been re-excavated by the Franco-Cambodian Prehistoric Mission (MNHN-Ministry of Culture and Fine Arts, Cambodia). The abundant archaeological remains collected between 2009 and 2015 represent the database of this Ph.D. and have now been complemented the archaeological occupations on 5 meters of a long sequence. The cultural layers included lithic artefacts (pebbles and flint), pottery, animal bones, and human burials. The new results from seven years of excavation campaigns reveal three main occupation layers ranging from 71 000 BP to 3000 BP: Neolithic, Hoabinhian, and Pre- Hoabinhian levels. A new chronological framework was obtained using modern complementary methods (14C, OSL, U-Th dating and mineral fraction). We were able to discuss the Hoabinhian occupation (last hunter-gatherers of Southeast Asia) and replace the Pleistocene - Holocene transition. Previous Hoabinhian level (11 to 71ka), another hunter-gatherers occupation was registered with animal remains and flint flakes, which lead to question about the succession of prehistoric human activities before the Holocene in this limestone region of Northwestern Cambodia. The chronological and archaeo-stratigraphic results allow us now to better understanding the position of the Hoabinhian techno-complex in its cultural, environmental and spatial framework for the purpose of future comparisons with other hunter-gatherer sites in Mainland Southeast Asia. Finally, the Laang Spean study case shows an association of two kinds of occupation and territory exploitation: a living camp for Hoabinhian hunters and a burial site during the Neolithic period
24
Ettinger, Susanne. "Geomorphological impact of lahars on the southwestern flank of Cotopaxi volcano, Ecuador : drainage system and alluvial fan". Thesis, Clermont-Ferrand 2, 2012. http://www.theses.fr/2012CLF20017.
Testo completoAbstract (sommario):
Pendant une éruption volcanique sur des sommets englacés, des coulées de débris syn-eruptifs,dénommées lahars, peuvent être générées par la fonte partiale de glaciers. Ce phénomène estbien connu sur le volcan Cotopaxi, Equateur. La présente étude concerne trois vallées et un cônede déjection sur le flanc sud-ouest de ce volcan. Une première analyse a été conduite par relevésde formes géomorphologiques dans ces vallées qui témoignent des processus d’érosion et desédimentation lors du passage de lahars dans le passé, notamment ceux du dernier événementéruptif datant de 1877 AD. Bien que les types des formes géomorphologiques déterminées sontles mêmes, leur distribution spatiale varie d’une vallée à l’autre en fonction d’une interaction deparamètres morphologiques locaux. Les conditions environnementales individuelles déterminentégalement le volume de l’écoulement, paramètre crucial dans la délimitation de zones de risques delahars dans les plaines adjacentes. Pour cela, une deuxième étude a été menée à grande échelle surle cône de déjection à l’exutoire de la vallée la plus au Sud des trois. Une analyse intégrale de la morphologiede surface et des affleurements naturels a été complétée par des données stratigraphiquesde subsurface obtenues via un sondage avec un Géoradar. Reconstituer l’architecture sédimentairede ce cône permet de visualiser la distribution spatiale de formes érosives et de dépôts. L’étude àrévélé que différentes parties du cône sont actives à des moments distincts et les épaisseurs dedépôts de lahars sont variables en fonction du type d’écoulement et de son volume. Ceci permetde relier les dynamiques géomorphologiques des plaines alluviales aux zones d’initiation de laharssur les flancs du volcan. Enfin, cette étude a débouché sur la mise en place d’une nouvelle fonctiondans le logiciel de modélisation de lahars LAHARZ prenant en compte l’incorporation progressive desédiment dans un contexte érosif dans les vallées, ce qui permet une meilleure délimitation de zonesde risque de lahars sur le côneDuring a volcanic eruption at ice capped volcanoes, syn-eruptive volcanic debris flows, lahars, canbe triggered through the partial melting of the glaciers. This phenomenon is well known to have happenedat Cotopaxi volcano, Ecuador, where the present study has been realized. The latter concernsthree drainages on the southwestern flank of the volcano and one alluvial fan. A first analysis hasbeen conducted assessing geomorphologic features in the drainages testifying from erosional anddepositional processes during past lahars, in particular of those generated during the last eruptiveevent dating back to 1877 AD. Although the types of determined geomorphologic features are thesame, their spatial distribution varies among the three valleys as a function of an interplay of localmorphologic parameters. The individual environmental conditions determine also the flow volumeof such lahars, a critical parameter when to delineating hazard zones in the adjacent lowlands. Thesecond analysis has therefore be performed at large scale on the alluvial fan forming at the mouthof the southernmost of the three drainages. An integral study of the surface morphology and naturalexposures was enriched with subsurface stratigraphic information obtained through a ground penetratingradar survey. The sediment architecture of the fan provides valuable insights on the distributionof erosional features and deposits. Different fan parts appear to be active at different times andlahar deposit thicknesses are highly variable as a function of flow type and volume. This allows torelate floodplain dynamics to the initiation zone of lahars on the upper flanks of the volcano. At last,this research led to integrate a new bulking function acknowledging for erosional processes in thevalleys into the lahar-modeling software LAHARZ allowing to better delineate lahar hazard zones onthe fan
25
Pereira, Camila Tavares 1988. "Paleossolos da Formação Marília no município de Campina Verde, oeste de Minas Gerais". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/286629.
Testo completoAbstract (sommario):
Orientador: Alessandro BatezelliDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
Made available in DSpace on 2018-08-25T01:50:06Z (GMT). No. of bitstreams: 1 Pereira_CamilaTavares_M.pdf: 6719830 bytes, checksum: c010edfeb787dd0ffb56ed12b5a56676 (MD5) Previous issue date: 2014
Resumo: A Formação Marília, que aflora no sudeste do Brasil, é uma sucessão sedimentar caracterizada por estratos sedimentares alternados com paleossolos. As feições pedogenéticas podem ser relacionadas com os fatores climáticos e são utilizadas como ferramenta na interpretação de paleoambientes. Através da descrição macro e microscópica, associada a análise mineralógica e fluorescência de raios-X, foram identificados e caracterizados 20 de perfis de paleossolos da Formação Marília, Maastrichtiano da Bacia Bauru. A intercalação de horizontes C, Ck, Bt, Btk e Gley, possibilitaram a elaboração de um modelo de evolução paleoambiental, onde os dados geoquímicas permitiram tecer considerações paleoclimáticas. As mudanças nos processos de formação destes paleossolos foram impulsionadas principalmente pelas variações de umidade disponível. As estimativas de paleoprecipitação (MAP) obtidas por meio do CIA-K em horizontes Bt e Btk, indicam que a pluviosidade variou de 20-1000 mm/ano. Estas condições climáticas contrastantes resultaram na sobreposição de perfis distintos, sugerindo oscilação entre condições áridas a semiáridas. Estes resultados contribuem para um melhor entendimento paleoambiental do Cretáceo Tardio para a porção sudeste brasileira
Abstract: The Marília Formation is the Maastrichtian sequence of the Bauru Basin and crops out in southeastern Brazil. It is a sedimentary succession characterized by alternating sedimentary strata and paleosols. The pedogenic features can be related to climatic factors and are used as a tool in the interpretation of paleoenvironments. By means of a macro- and microscopic description, associated with mineralogical and x-ray fluorescence analyses, twenty paleosol sections were identified and characterized in the Marília Formation. The characterization of C, Ck, Bt, Btk and Gley horizons and the corresponding geochemical data helped define a paleoenvironmental evolutionary model and make some paleoclimatic considerations. Changes in the processes of formation of these paleosols were mainly triggered by moisture variations. Paleoprecipitation estimates (MAP) obtained by means of CIA-K in Bt and Btk horizons indicate that precipitation varied 20-1000 mm/year. These contrasting climatic conditions caused overlapping of distinct profiles, suggesting oscillation between arid to semi-arid conditions. These results contribute to a better understanding of the Upper Cretaceous paleoenvironment in southeastern Brazil
Mestrado
Geologia e Recursos Naturais
Mestra em Geociências
26
Woodfine, Richard Gareth. "Chemostratigraphy of Jurassic-cretaceous Italian carbonate platforms". Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:03c84d34-a27d-46fd-89b0-d69a1501d888.
Testo completoAbstract (sommario):
Samples of shallow-water carbonates were collected from Jurassic and Cretaceous Italian carbonate platforms and subjected to petrographic, diagenetic and chemostratigraphic analyses (87Sr/86Sr, δ13Ccarb, δ13Corg, δ18O). In general, the new chemostratigraphic data generated reflect trends established by previous work, some of which has been carried out on biostratigraphically calibrated reference sections. Consequently, chemostratigraphic correlations (87Sr/86Sr, δ13Ccarb) of isotope profiles taken from platform carbonates with well-dated reference sections have allowed the application of high-resolution dating frameworks to the biostratigraphically poorly constrained carbonate platforms. The increased resolution in dating of the Italian carbonate platforms has, furthermore allowed a detailed investigation into the facies response of these carbonate platforms to major geological events. In particular, platform responses to oceanic anoxic events and other periods of major perturbation in the global carbon cycle are analysed (early Toarcian, Aalenian-Bajocian, Oxfordian-Tithonian, Valanginian-Hauterivian, Aptian-Albian, Cenomanian-Turonian, Coniacian-Santonian). Lower Jurassic levels of the Trento Platform record platform devastation in the early Toarcian synchronous with a major negative δ13Ccarb excursion, followed by platform recovery synchronous with a pronounced δ13Ccarb positive excursion and return to background values. The Campania-Lucania Platform shows negligible response to the oceanographic events of the early Toarcian even though the characteristic carbon-isotope profile is readily identifiable. The Trento Platform drowned at approximately the Aalenian-Bajocian Stage boundary, synchronously with a reproducible negative followed by positive δ13Ccarb excursion, whereas the Campania-Lucania Platform underwent a facies transition from oolite to cyclically bedded micrite. The Friuli Platform showed negligible depositional response to the carbon-cycle perturbations of the Kimmeridgian-Tithonian, Valanginian-Hauterivian, Aptian-Albian and Cenomanian- Santonian (as registered in the δ13Ccarb record). The Campania-Lucania Platform registered flooding and increased levels of organic-matter preservation coincident with pronounced positive δ13Ccarb excursions at Cenomanian-Turonian and Coniacian-Santonian levels. Observations on the responses of carbonate platforms to oceanographic conditions during periods of global carbon burial lead to the conclusion that temperature excess is a hitherto neglected control on global carbonate accumulation rates.
27
Fondrillon, Mélanie. "La formation du sol urbain : étude archéologique des terres noires à Tours (4e-12e siècle)". Phd thesis, Université François Rabelais - Tours, 2007. http://tel.archives-ouvertes.fr/tel-00256362.
Testo completoAbstract (sommario):
Cette étude s'inscrit dans le courant des études archéologiques et géoarchéologiques qui, depuis une trentaine d'années en Europe du Nord-Ouest, ont permis de renouveler une partie des connaissances sur la ville du haut Moyen Âge par l'analyse des terres noires urbaines. Encore trop peu considérées aujourd'hui, ces dernières représentent pourtant une archive de l'histoire des villes d'origine antique.L'étude présente un intérêt méthodologique et analytique. Elle propose une méthode d'acquisition et de traitement des données spécifique aux stratifications archéologiques en contexte historique. L'expérience a été menée sur cinq sites archéologiques à Tours (Indre-et-Loire), en considérant la composition sédimentaire, grossière et fine, des dépôts mis au jour. Cette analyse repose sur le postulat que les traces des activités humaines sont enregistrées dans la composition sédimentaire des couches archéologiques. Par l'application des principes de formation des stratifications, développés initialement par les préhistoriens et les géologues, l'étude permet de caractériser les usages anthropiques à l'origine de ces séquences urbaines, après avoir mis en place un référentiel fonctionnel de couches archéologiques fondé sur des critères discriminants.
À l'échelle du site, les séquences de terres noires étudiées témoignent d'activités spécifiques et variées : ont ainsi été mis en lumière des parcelles cultivées, des zones d'habitat et de rejets domestiques, des espaces extérieurs occupés ou encore des activités de récupération de matériaux de construction. Les résultats montrent que ces séquences, en apparence non stratifiées, ont été produites par des activités humaines diversifiées, que les processus post-dépositionnels ont le plus souvent oblitérées.
À l'échelle de la ville, les terres noires attestent les changements progressifs qui affectent les rapports des habitants à la ville. Ainsi cette étude, intégrée aux recherches urbaines développées depuis les années 1990, contribue à la reconnaissance de nouvelles pratiques sociales de l'espace urbain à partir du Bas-Empire, témoignant de nouveaux modes d'occuper, d'habiter, de construire.
28
Zanella, Sandra. "Bâtiments privés sur sol public ? : les maisons en terrasse de Pompéi entre le forum et les murailles". Thesis, Paris 1, 2015. http://www.theses.fr/2015PA010707.
Testo completoAbstract (sommario):
Les maisons de Pompéi sujets de cette recherche (Casa di Championnet I et II : Casa dei Mosaici geometrici), nous ont permis d’analyser un point privilégié de Pompéi. Bâties dans la zone au sud du forum, en partie en utilisant les remparts de la ville, ces édifices se caractérisant pour se développer sur plusieurs niveaux de terrasses qui échelonnent vers la plaine du fleuve Sarno et les horrea de Pompéi. Cette conformation particulière fait de ces édifices un point de première importance pour observer l’évolution urbanistique de Pompéi entre IIIe siècle avant notre ère et sa destruction en 79. En appliquant les principes de la stratigraphie du bâti, nous avons pu identifier les phases de développement de celle qui est aujourd’hui la plus grande maison connue à Pompéi, fruit de l’union de plusieurs édifices indépendants. Ce travail, au-delà de permettre une étude de détail d’un monument particulier, permet de poser un regard nouveau sur l’intégralité du tissu urbain de Pompéi. L’analyse de ces édifices en lien avec les résultats venant des récentes recherches stratigraphiques pratiquées dans de multiples points de la ville, permet de recevoir l’évolution du site samnite et romainThe houses of Pompeii subjects of this research (Casa dui Championet I and II ; Casa dei Mosaici geometrici), allowed us to analyze a privileged point of Pompeii. Built in the area south of the forum, in part by using and destroying the city walls, these buildings are characterized to develop multi-level terraces that range to the plains of the Sarno River and horrea of Pompeii. This particular structure of these buildings is a point a great importance to observe the urban development of Pompeii between the third century of BC and its destruction in 79. In applying the principles of stratigraphy of the frame, we were able to identify the phases development which is now the largest known house in Pompeii, fruit of the union of several independant buildings. This work, in addition to allow a detailed study of a particular monument, allows a new perspective on the entire urban fabric of Pompeii. Analysis of these buldings in line with the results from recent stratigraphic investigations undertaken in many parts of the city, allows you to review the evolution of the Samnite and Roman site
29
Aunay, Bertrand. "Apport de la stratigraphie séquentielle à la gestion et à la modélisation des ressources en eau des aquifères côtiers". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2007. http://tel.archives-ouvertes.fr/tel-00275467.
Testo completoAbstract (sommario):
Lieu de développement économique et démographique intense, les zones littorales font l'objet de pressions importantes sur l'environnement et, en particulier, sur les ressources en eau. Bien que la gestion des eaux souterraines côtières bénéficie de nombreux résultats issus de la recherche scientifique, une des problématiques majeures reste la connaissance de la géométrie des aquifères. Des interprétations géologiques de la genèse du bassin Plio-Quaternaire du Roussillon, issues de la stratigraphie séquentielle, sont confrontées, par l'intermédiaire d'une base données, à l'hydrogéologie de cet hydrosystème complexe localisé sur la partie littorale des Pyrénées-Orientales. L'étude statistique des points de prélèvement (distribution des crépines, productivité des forages...), l'analyse fonctionnelle (traitement du signal des chroniques piézométriques), l'hydrochimie et la géophysique électrique ont été utilisées afin d'élaborer un modèle conceptuel hydrogéologique des écoulements à l'échelle du bassin et de son prolongement vers le domaine offshore. La présence de la mer, de zones à salinité résiduelle et de cours d'eaux littoraux contribue à augmenter la salinité d'un aquifère libre supérieur (Quaternaire) sus-jacent aux différents aquifères captifs (Pliocène) exploités pour l'eau potable dans la zone littorale. La vulnérabilité face aux intrusions salines de cette ressource de bonne qualité, tant sur le point de vue quantitatif que qualitatif est appréhendée par modélisation. Dans le domaine offshore, le rôle protecteur des formations géologiques à faible et moyenne perméabilité est mis en évidence vis-à-vis de la préservation de la qualité de l'eau potable.
30
Barles, Sabine. "La pédosphère urbaine : le sol de Paris XVIIIe-XXe siècles". Phd thesis, Ecole Nationale des Ponts et Chaussées, 1993. http://tel.archives-ouvertes.fr/tel-00523028.
Testo completoAbstract (sommario):
Ce travail traite d'une partie souvent oubliée de la ville, le sous-sol peu profond qui accueille les réseaux, les racines de la végétation, les déchets urbains, à travers le cas français, parisien en particulier. Dans une première partie, on met en exergue les dysfonctionnements actuels de la pédosphère urbaine : dégradations des réseaux, de la végétation, perturbation des nappes, etc. Dans la seconde partie, on recherche les racines historiques de la perte de connaissance sur le sol urbain en analysant les doctrines scientifiques et techniques qui se succèdent du XVIIIe au XXe siècles chez les médecins, géographes et ingénieurs. On montre comment les premiers ont analysé le rôle du sol dans l'épidémiologie urbaine au XVIIIe siècle puis ont perdu cette sensibilité dès la restauration en substituant la statistique à l'observation, avant de se tourner vers le milieu intérieur à la fin du XIXe siècle. Les géographes ont permis, malgré de nombreuses difficultés, la reconnaissance de la topographie urbaine en élaborant les outils cartographiques de représentation du relief, qui sont repris par les ingénieurs des Ponts et Chaussées auxquels est confiée au XIXe siècle la rectification de la ville. On insiste sur les difficultés que rencontrent ces derniers à saisir la nature du sol, qui se traduit par la mathématisation de la poussée des terres et l'empirisme dans les techniques de fondation. Les transformations de la ville, ébauchées sous le Premier Empire, entraînent dès la Monarchie de Juillet une série de dysfonctionnements dans la gestion du sol urbain : revêtement des rues, apparition du déchet liquide. Le sol industriel n'est plus considéré pour sa valeur artisanale ou son rôle délétère mais accueille parfois les eaux usées et est ravalé au rang de filtre. Si l'automobilisme permet l'accomplissement de la ville abiotique, on souligne le désintérêt des urbanistes, des hygiénistes (rarement médecins), des mécaniciens des sols du premier XXe siècle pour le milieu urbain. Un regain d'intérêt pour le sol urbain se manifeste dans l'Entre-deux-guerres, mais dans une nouvelle perspective, celle de l'urbanisme souterrain. Ces deux siècles et demi conduisent au chaos actuel du sous-sol et traduisent non seulement la complexité de l'industrialisation du sol mais aussi le désintérêt progressif de certaines disciplines scientifiques pour la ville dans laquelle elles ont vu le jour.
31
Sastre, Jurado Carlos. "Exploitation du signal pénétrométrique pour l'aide à l'obtention d'un modèle de terrain". Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC003/document.
Testo completoAbstract (sommario):
Ce travail porte sur la reconnaissance de sols à faible profondeur grâce aux données de résistance de pointe recueillies à l'aide de l'essai de pénétration dynamique à énergie variable, Panda®. L'objectif principal est d'étudier et de proposer un ensemble d'approches dans le cadre d'une méthode globale permettant d'exploiter les mesures issues d'une campagne de sondages Panda afin de bâtir un modèle géotechnique du terrain.Ce manuscrit est structuré en quatre parties, chacune abordant un objectif spécifique :dans un premier temps, on rappelle les principaux moyens de reconnaissance des sols, notamment l'essai de pénétration dynamique Panda. Ensuite on réalise un bref aperçu sur le modèle géotechnique et les techniques mathématiques pour décrire l'incertitude dans la caractérisation des propriétés du sol;la deuxième partie porte sur l'identification automatique des unités homogènes du terrain, à partir du signal pénétrométrique Panda. Suite à l'étude réalisée sur l'identification "experte" des couches à partir du signal Panda, des approches statistiques basées sur une fenêtre glissante ont été proposées. Ces techniques ont été étudiées et validées sur la base d'un protocole d'essais en laboratoire et sur des essais effectués en sites naturels et en conditions réelles;la troisième partie porte sur l'identification automatique des matériaux composant les unités homogènes détectées dans le signal Panda à partir des méthodes proposées en partie II. Une méthode de classification automatique basée sur des réseaux de neurones artificiels a été proposée et appliquée aux deux cas d'étude : la caractérisation de sols naturels et la classification d'un matériau granulaire argileux industrialisé (bentonite) ; enfin, la dernière partie est consacrée à la production d'un modèle de terrain basé sur la modélisation et la simulation de la résistance de pointe dynamique au moyen de fonctions aléatoires de l'espace. Cette modélisation est basée sur une approche par champs aléatoires conditionnés par les sondages Panda du terrain. Sa mise en œuvre a été étudiée pour un terrain expérimental situé dans la plaine deltaïque méditerranéenne en Espagne. Des études complémentaires en vue de raffiner cette démarche ont été réalisées pour un deuxième site expérimental dans la plaine de la Limagne en FranceThis research focuses on the site characterization of shallow soils using the dynamic cone penetrometer Panda® which uses variable energy. The main purpose is to study and propose several techniques as part of an overall method in order to obtain a ground model through a geotechnical campaign based on the Panda test.This work is divided into four parts, each of them it is focused on a specific topic :first of all, we introduce the main site characterization techniques, including the dynamic penetrometer Panda. Then, we present a brief overview of the geotechnical model and the mathematical methods for the characterization of uncertainties in soil properties;the second part deals with the automatic identification of physical homogeneous soil units based on penetration's mechanical response of the soil using the Panda test. Following a study about the soil layers identification based only on expert's judgment, we have proposed statistical moving window procedures for an objective assessment. The application of these statistical methods have been studied for the laboratory and in situ Panda test;the third part focuses on the automatic classification of the penetrations curves in the homogeneous soil units identified using the statistical techniques proposed in part II. An automatic methodology to predict the soil grading from the dynamic cone resistance using artificial neural networks has been proposed. The framework has been studied for two different research problems: the classification of natural soils and the classification of several crushed aggregate-bentonite mixtures;finally, the last chapter was devoted to model the spatial variability of the dynamic cone resistance qd based on random field theory and geostatistics. In order to reduce uncertainty in the field where Panda measurements are carried out, we have proposed the use of conditional simulation in a three dimensional space. This approach has been applied and studied to a real site investigation carried out in an alluvial mediterranean deltaic environment in Spain. Complementary studies in order to improve the proposed framework have been explored based on another geotechnical campaign conducted on a second experimental site in France
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Verble, Kathy K. "Investigations of soil morphology, hydrology, reduction-oxidation potentials, and stratigraphy on a selected hillslope in western Oregon". Thesis, 1998. http://hdl.handle.net/1957/33591.
Testo completo
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Jacobs, P. M. "Stratigraphy, landscape evolution, and a Pleistocene buried soil lithosequence in the Flatwoods region of Owen and Monroe Counties, Indiana". 1994. http://catalog.hathitrust.org/api/volumes/oclc/31315931.html.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of Wisconsin--Madison, 1994.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 158-171).
34
Adewumi, Opeyemi Lateef. "Soil micromorphology of the sedimentary samples from Anta 1 de Vale da Lage, Tomar, Portugal". Master's thesis, 2019. http://hdl.handle.net/10400.26/31618.
Testo completoAbstract (sommario):
This master thesis is based on the soil micromorphological study of the sedimentary samples from Anta 1 de Vale da Laje site, located in Tomar, Portugal. The site of Anta 1 de Vale da Laje is one of the sites currently under study within the research framework of the projects Landscape occupation strategies during the Holocene in the Middle Tagus (Es.Ter.Tejo) and Moving tasks across shapes: the agro-pastoralists spread from and into the Alto Ribatejo (MTAS). Asides the stratigraphic problems of the site, it remained unclear the modification successions in time, of the monument and the processes that can be attributed to their sequencing, which were scopes of the abovementioned projects.
Micromorphological study of human impact and natural processes on the environment has been reliant on the interpretation from the study of the undisturbed palaeosols. This study applied the methodological approach of soil micromorphological analyses to understand both the stratigraphic sequence and the evolution of the megalithic tomb of Anta 1 de Vale da Laje site where stratigraphic continuity and discontinuity were observed.
The result of the analyses recognized six (6) periods of activities and three (3) phases of site evolution, as well as identification of human activities relating to agricultural practices, constructions and natural processes such as weathering, leaching, and erosion resulting from impact of rainfall.
35
Zomeni, Zomenia. "Quaternary marine terraces on Cyprus : constraints on uplift and pedogenesis, and the geoarchaeology of Palaipafos". Thesis, 2012. http://hdl.handle.net/1957/30355.
Testo completoAbstract (sommario):
Numerous flights of Quaternary marine terraces are present around the island of Cyprus, in the Eastern Mediterranean. These terraces are a result of the global eustatic sea-level curve and local tectonism. Marine Isotope Stage (MIS) 5 through MIS 13 terraces are identified, mapped and dated. Palaeoshoreline elevation, an excellent indicator for a past sea–level, and new numerical geochronology are used to calculate an Upper Pleistocene uplift rate for various coastal sectors. Southwestern Cyprus presents the highest uplift rates of 0.35-0.65 mm/year with other sections suggesting uplift of 0.07-0.15 mm/year. This Upper Pleistocene tectonic signal is attributed to an active offshore subduction/collision system to the southwest of Cyprus, evidenced from the seismic activity offshore and the surface expression of a blind thrust fault in the Pafos region.
Soil chronosequences and geology in southwestern Cyprus are studied in order to understand the Quaternary development on this uplifting landscape. Soil profile properties are used to calculate a profile development index (PDI), a method often applied to geomorphic surfaces as a relative dating method. Well-developed red and clayey soils occur in the coastal sector, on broad and low-angle surfaces, specifically on marine terraces and alluvial fans. Higher elevations of steep slopes consisting of carbonate and ophiolite lithologies host poorly developed soils. Results show variable PDI's on uplifted terraces, obscured by transported materials, active alluvial fan buildup and hillslope erosion. Calcium carbonate build-up in soil profiles in the form of nodular and laminar accumulations are used as another relative dating method. Geochronology of marine terraces is used as an age range approximation for carbonate stages.
Geomorphologic mapping focuses on the southeastern part of the Pafos thrust fault, the only point on the landscape where this otherwise blind fault is exposed on the surface. This is the location of Palaipafos, an important Ancient polity, today the site of the village of Kouklia. Geoarchaeological study suggests little landscape change over the last 4000 years in the vicinity of the urban core of Palaipafos, this being attributed to bedrock and landscape resistance of its location, a plateau at 80 m amsl. Copper deposits in the Palaipafos hinterland had provided a valuable resource at one time. Soil and water resources continue to sustain agriculture.Tectonic uplift in this part of the Pafos thrust fault is estimated to be 2.1mm/year, considered, together with Late Holocene sea-level change responsible for the shifting locations and eventual abandonment of the Palaipafos harbor in the coastal lowlands.Graduation date: 2013
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D'Amore, David V. "The stratigraphy, hydrology, and redoximorphic character of the Jackson-Frazier wetland". Thesis, 1994. http://hdl.handle.net/1957/35207.
Testo completoAbstract (sommario):
Transitional areas between upland and aquatic habitats, commonly known as
wetland, were once viewed as unproductive areas and were drained for farming or
pasture. Wetlands are now accepted as significant ecological resources, and their
protection is a mandate of federal, state, and local land managers. Due to the
diversity of wetland areas, the appropriate assessment of wetland resources cannot
be accomplished without long term monitoring of wetland functions. Knowledge of
the duration of saturation and associated anaerobic conditions of soils in wetlands is
critical to correctly classify and assess wetland areas.
Soil, hydrological, and biogeochemical characteristics of the soils of the
Jackson-Frazier wetland were observed from October 1992 through March 1994.
Weekly observations of water levels and redox potential at depths of 25, 50, and 100
cm were made in order to characterize the degree and duration of saturation and the
anaerobic conditions in the soil over time.
Permanently installed piezometers measured free water in the soil and
indicated the presence of two separated water tables from the onset of the rainy
season in October until February when the entire soil profile became saturated with
free water. Platinum electrodes measured redox potential in the soil and indicated
anaerobic conditions for ten months during the first season of observation and through March of the second season. Anaerobic conditions were considered to be achieved when Fe����� was reduced to Fe����� at a potential of 200 millivolts. The highly reducing conditions correspond to periods of soil saturation indicated by piezometers. Concentrations of iron and manganese observed in soil profiles correspond to conditions of prolonged saturation and reduction confirmed by monitoring.
A soil stratigraphic study done with auger holes revealed a recent alluvial deposit of montmorrillonitic clay overlying lacustrine silts identified as the Irish Bend Member of the Willamette Formation. The clay deposit overlying the surface of the wetland acts as an aquitard and creates extensive surface ponding, which maintains the saturated habitat required for wetland vegetation. The subsurface hydrology is controlled by water flowing through the Irish Bend silts which results in saturation of the soils from below. Biogeochemical transformations of iron and manganese due to suboxic and anaerobic conditions are controlled by this type of soil saturation in the Jackson-Frazier wetland.Graduation date: 1995