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Lundquist, Jason James. "Foraminiferal biostratigraphic and paleoceanographic analysis of the Eagle Ford, Austin, and Lower Taylor groups (Middle Cenomanian through Lower Campanian) of central Texas /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Buchan, Olivia Claire Lewis Ronald D. "Relationships between large benthic foraminifera and their seagrass habitats, San Salvador, Bahamas." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Spring/master's/BUCHAN_OLIVIA_31.pdf.
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Caromel, Aude Genevieve Marcelle. "Form and function in planktic foraminifera." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.628998.
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Planktic foraminiferal tests and their morphology have been the subject of extensive study for biostratigraphy and palaeoenvironmental reconstructions. Iterative evolution of morphological designs and correlations between morphology and environmental parameters suggest either fundamental intrinsic constraints on form , or a functional control, or both. Yet the adaptive significance of the test morphologies in terms of these constraints has never been rigorously explored, and is the focus of this thesis. The developmental and growth constraints delimiting the scope of action for evolution were determined through ontogenetic reconstructions based on SRXTM scans. Differences in growth patterns between the globigerinid and globorotalid groups imply a different potential for diversification. Different metabolic processes dominate growth at different stages of ontogeny due to changes in surface area-to-volume ratios, so mechanisms of evolution responding to environmental factors may change depending on when they occur in ontogeny. Imposed on these are constructional considerations, which were gauged through estimation of coiling patterns through ontogeny from the reconstructions. Coiling in early ontogeny is constrained across all species to maximise lateral growth. From the neanic stage, changes in coiling occur to accommodate new chamber shapes, and are modulated by the migration of the aperture. Developmental processes of evolution must therefore operate within this framework. Computational fluid dynamic simulations were used to assess the functional role of the test in adjusting settling velocity, by varying morphological and water parameters independently. The range of evolutionary options open to foraminifera is a result of trade-offs between changes in size, shape and density, and environmentally required fluctuations can easily be accommodated by the natural within-population variability. The findings of this thesis imply that, in the compromise between function and constraints acting with the environment to define adult morphology and diversification, intrinsic factors are likely to play a more important role than function in plank tic foraminifera.
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Pearson, Paul Nicholas. "Evolution and phylogeny of Palaeogene planktonic foraminifera." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386154.
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Seears, Heidi. "Biogeography and phylogenetics of the planktonic foraminifera." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/11879/.
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The planktonic foraminifera are a highly abundant and diverse group of marine pelagic protists that are ubiquitously distributed throughout the worlds’ oceans. These unicellular eukaryotes are encased in a calcareous (CaCO3) shell or ‘test’, the morphology of which is used to identify individual ‘morphospecies’. The foraminifera have an exceptional fossil record, spanning over 180 million years, and as microfossils provide a highly successful paleoproxy for dating sedimentary rocks and archiving past climate. Molecular studies, using the small subunit (SSU) ribosomal (r) RNA gene are used here to investigate the biogeographical distributions and phylogenetic relationships of the planktonic foraminifera. Biogeographical surveys of two markedly different areas of the global ocean, the tropical Arabian Sea, and the transitional/sub-polar North Atlantic Ocean, revealed significant genotypic variation within the planktonic foraminifera, with some genetic types being sequenced here for the first time. The foraminiferal genotypes displayed non-random geographical distributions, suggestive of distinct ecologies, giving insight into the possible mechanisms of diversification in these marine organisms. The ecological segregation of genetically divergent but morphologically cryptic genetic types could, however, have serious repercussions on their use as paleoproxies of past climate change. Phylogenetic analyses of the foraminifera based firstly on a partial ~1,000 bp terminal 3´ fragment of the SSU rRNA gene, and secondly on the ~3,000 bp almost complete gene supported the hypothesis of the polyphyletic origins of the planktonic foraminifera, which appear to be derived from up to 5 separate benthic ancestral lineages. The almost complete gene is sequenced here in the planktonic taxa for the first time, though amplification was problematic. In a first step to addressing a pressing need for new genetic markers to support data gained from the SSU rRNA gene, a culture system was established for the benthic foraminifera, in order to provide a reliable source of DNA for EST library construction or full genome sequencing. Finally, to overcome difficulties associated with the PCR amplification of the foraminifera, a new lysis buffer and DNA extraction procedure was developed. A highly successful buffer was created, allowing high quality DNA to be extracted from foraminiferal specimens, whilst leaving the delicate calcitic shell intact for morphological reference.
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Ward, Juliette Natalie. "Foraminifera as proxiles for monitoring organic pollution." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398830.
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Al-Sayigh, Abdul Razak Siddiq. "Lower Tertiary Foraminifera from south east Oman." Thesis, Aberystwyth University, 1999. http://hdl.handle.net/2160/1a8d5b93-df4b-412e-aecb-38c02de78e03.
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Over 250 samples were collected over three field seasons from the SE Oman Mountains. Fortyone species of planktonic Foraminifera (belonging to 7 genera) and twenty-eight species of larger benthonic Foraminifera, (belonging to 13 genera) are figured (both by SEM and optical photography) from the Wadi Musawa and Wadi Suq sections. Nine planktonic foraminiferal zones are formally recognised between the Upper Palaeocene(P 4) and upper Middle Eocene (P14). The known stratigraphic distribution of these species was used to recognise the zones P 5, P8-P9 as equivalentt o standard zones of Blow, 1969,1979, whilst strata considered generally equivalent to P4 and PIO-PI4 in the Wadi Musawa section are zoned on the basis of the local range. Younger sediments can only be dated on larger Foraminifera. A possible hiatus representing the planktonic zones P 6/P7 is tentatively identified. Fifteen lithostratigraphic units are recognised and formally described from three formations: the Abat Formation( units A-D), the Musawa Formation (units E-L) and the Tahwah Formation (units M-0). The ages of the Abat and Musawa formations are redefined and are shown to be significantly older than previously published. Biostratigraphical and palaeoenvironmental data from both the planktonic and the larger Foraminifera has been used in conjuction with the lithostratigraphy to construct a sequence stratigraphy, in which several cycles have been recognised. Some of these cycles may correlate with the global sea-level cycles of Haq et al. (1987) and include TA2.3 and TAM, Whilst others are local due to tectonically induced regressive and transgressive events. Information not only from the Foraminifera but also from radiolaria, ostracods and molluscs has been used to reconstruct the palaeoenvironment for the Omani Palaeogene. Parts of the Lower and Middle Eocene contain in-situ larger Foraminifera indicating deposition in a shelf (dominantly mid to outer) setting. During the late Palaeocene, most of the early Eocene, part of the middle Eocene, and the entire late Eocene/early Oligocene mixed assemblages of planktonics and shallow water benthonics were the dominant Foraminifera. The occurrence of the these two assemblages in deepwater sediments indicates a substantial period of time in which penecontemporaneous uplift and resedimentation of carbonate shelf deposits into deeperwater occurred. A number of new larger and smaller benthonic Foraminifera are described and one planktonic foraminifer renamed.
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Coxall, Helen Katherine. "Hantkeninid planktonic foraminifera and Eocene palaeoceanographic change." Thesis, University of Bristol, 2000. http://hdl.handle.net/1983/8efa1d22-0ff8-45a3-9a5c-bd5ea90e266f.
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The morphological and ecologicalevolution of middle-upper Eocene planktonic foraminiferal family Hantkeninidae is investigated in the context of the dramatic palaeoceanographic and climatic changes that marked the transition from Paleogene "greenhouse" to Neogene "icehouse" climatic conditions. Morphometric analysis proves that evolution in family Hantkeninidae was gradual but complex in detail with periods of relative stasis. Multiple lines of evidence demonstrate that Hantkenina evolved from planispiral clavate genus Clavigerinella and not, as was previously believed, from Pseudohastigerina micra. The ancestor of Clavigerinella was probably a low trochospiral form Paragloborotalia sp., which has been recognized for the first time in this study at a number of sites. Trends in chamber inflation, tubulospine angle and the position of the tubulospine on each chamber show the most dramatic evolutionary changes, indicating that these are the most useful characters for taxonomy. These morphological changes correlate well with known palaeoceanographic changes as well as the shift in hantkeninid ecology from a deep to a surface water habitat. Hantkeninids underwent pronounced adaptive evolution in depth habitats during the initial phase of the climatic transition. Lower middle Eocene forms lived in a cool deep-water environment within or below the oceanic thermocline and shifted to warmer surface waters in the late middle Eocene. They evolved in the low latitudes and were primarily. a tropical-subtropical group. The occurrence of Hantkenma australis at relatively high northerly and southerly latitudes during the middle Eocene may record a temporary expansion of warmer water conditions into these regions, possibly representing a hitherto unknown "hyperthermal" event. Clavigerinella is rare in middle Eocene open-ocean sequences but occasionally occurs in relative abundance in other localities (such as on continental margins and oceanic seamounts), suggesting that it was specialized for living in upwelling regions. A revised taxonomy of family Hantkeninidae is presented that reflects new understanding ofhantkeninid evolution. The reconstructed phylogeny demonstrates that the tubulospine-bearing genera Hantkenina and Cribrohantkenina represent a monophyletic clade. Multivariate analysis suggests that more than one morphological population existed at several times and that these may represent biological species. The results demonstrate that the hantkeninids are not merely passive recorders of ocean conditions but have instead evolved morphology and changed habitat in response to climate change.
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Licari, Laetitia. "Ecological preferences of Benthic Foraminifera in the Eastern South Atlantic : distribution patterns, stable carbon isotopic composition, and paleoceanographic implications = Ökologische Ansprüche benthischer Foraminiferen im östlichen Südatlantik /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 2006. http://www.gbv.de/dms/bs/toc/514912308.pdf.
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Hudson, Wendy. "The evolution and palaeobiogeography of Mesozoic planktonic foraminifera." Thesis, University of Plymouth, 2007. http://hdl.handle.net/10026.1/719.
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In the 1960s Oberhauser and Fuchs (palaeontologists working at the Geologische Bundesanstalt in Vienna) described a range of new taxa from the Triassic of Austria that were thought to be the earliest planktonic foraminifera. The first reactions of the palaeontological community were negative but in the subsequent forty years our knowledge of Jurassic planktonic foraminifera has expanded considerably. A thorough re-evaluation of the Oberhauser and Fuchs collections in Vienna has shown that these species are probably not planktonic and that the first planktonic taxa appeared in the Toarcian. This origination in the centre of Western Tethys was followed by a rapid expansion of planktonic foraminifera throughout Peri-Tethys. This expansion is dominated by the genera Conoglobigerina and Globuligerina and while some believe that their separation is straightforward (based on apertural characters) analysis of large assemblages shows that this differentiation is not reliable and requires further analysis not only of holotypes, paratypes and topotypes but of large assemblages. In Southern Poland, Middle Jurassic limestones in the Pieniny Klippen Belt are described as foraminiferal packstones and represent the first evidence of a foraminiferal ooze on the ocean floor. This indicates that, by the mid-Jurassic, there was an oceanic stratification of the Aragonite and Carbonate Compensation Depths and that the modem ocean system had developed, although the depths of these various layers may have been different to those of the present day. By the Oxfordian a relatively diverse planktonic fauna had expanded throughout Peri- Tethys and, probably, around the globe in the tropics. The fauna expanded further in the early Cretaceous as Gondwana fragmented but data across the important Jurassic to Cretaceous transition is extremely limited and requires further investigation.
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Chapman, Mark Robert. "Late Pliocene planktonic foraminifera : palaeoceanography and faunal evolution." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332388.
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Khanna, Nikki. "The biological response of foraminifera to ocean acidification." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/8089.
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Elevated atmospheric concentrations of carbon dioxide (CO₂), partly driven by anthropogenic activity, are decreasing the pH of the oceans. This thesis aimed to assess the biological response of foraminifera to ocean acidification. Foraminifera are single-celled organisms that form the dominant component of many marine communities. A series of laboratory experiments were carried out on benthic intertidal foraminifera from the Eden and Ythan estuaries, NE Scotland, to assess the impacts of ocean acidification. The responses of two dominant intertidal species of foraminifera (Haynesina germanica and Elphidium williamsoni) to ocean acidification were initially investigated in a short-term (6 week) experiment. Multiple species and multiple stressors (seasonal temperature regime and elevated CO₂) were then incorporated in a long-term (18 month) mesocosm study to investigate the physiological consequences (e.g. survival, growth) of ocean acidification. Survival of both Haynesina germanica and Elphidium williamsoni was significantly reduced under low pH conditions. Live specimens of both these calcareous species were however recorded at low pH, in reduced numbers. Following long-term exposure to ocean acidification, foraminiferal populations were still dominated by calcareous forms. Agglutinated foraminifera were recorded throughout the long-term incubations but their numbers were not high enough in the initial sediment collections to allow them to contribute significantly to the populations. Overall, survival of all foraminifera was greatly reduced in elevated CO₂ treatments. Temperature effects were observed on foraminiferal survival and diversity with the largest CO₂ effects recorded under the seasonally varying temperature regime. Foraminiferal test damage for all live species was also highest under elevated CO₂ conditions. Test dissolution was particularly evident in Haynesina germanica with important morphological features, such as functional ornamentation, becoming reduced or completely absent under elevated CO₂ conditions. A reduction in functionally important ornamentation could lead to a reduction in feeding efficiency with consequent impacts on this organism's survival and fitness. In addition, changes in the relative abundance and activities of these important species could affect biological interactions (e.g. food web function) and habitat quality.
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Dos, Santos Francisco Kelmo Oliveira. "Ecological consequences of the 1997-98 El Niño Southern Oscillation on the major coral reef communities from northern Bahia, Brazil." Thesis, University of Plymouth, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246378.
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Speed, Craig Duncan. "High-resolution palaeoceanography of extreme early Pliocene carbonate-opal cycles in the eastern equatorial Pacific." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274423.
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Bordelon, Laura Anne. "AUSTRAL AUTUMN AND WINTER SEASONAL AFFECTS ON BENTHIC FORAMINIFERAL COMMUNITIES: BRANSFIELD AND NORTHERN GERLACHE STRAITS." OpenSIUC, 2009. https://opensiuc.lib.siu.edu/theses/150.
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The Southern Ocean has unique seasonal qualities due to the Antarctic Circumpolar Current (ACC) thermo-isolating the Antarctic continent. During summer months, surface primary productivity from algal blooms is very high. In the winter months, limited daylight hours (4 in winter) and formation of sea ice prevents sun light from reaching surface waters, therefore limiting productivity. The short seasons of productivity and long winters in Antarctica combined with seasonal changes in deep ocean temperatures, salinity, and fluxes of organic matter impact foraminiferal population dynamics. Fluctuations in surface primary productivity, as well as living foraminiferal assemblages have been documented around the Antarctica Peninsula, but the impact on benthic foraminiferal assemblages is poorly understood. This is a study of seasonal affects on benthic foraminiferal assemblages in the southern Bransfield-northern Gerlache Straits of the Southern Ocean. Surface sediment samples from 600 meters and 1200 meters water depth were collected during two seasonal cruises: early April to record the productivity of the end-of-summer bloom and late June to sample the less-productive winter period. Three hundred and sixty samples were collected from 7 sites and processed using standard techniques. To identify living foraminifera, samples were treated with Rose Bengal, and CellTracker Green on a select set of samples for comparison. Ninety total species were identified; seventy species from June and seventy-one from April, fifteen species of foraminifera unique to April, thirteen to June and two unique species in the CellTracker Green samples. The abundance of total living (stained tests) opportunistic benthic foraminiferal species from the 7 sampled sites show distinct temporal differences related to seasonality. An assemblage of deep water species was also found, as well as an assemblage of shallow water species. ANOVA and post hoc Tukey tests showed that the full cores must be analyzed to determine seasonal species assemblage changes. Cluster analysis and species abundances in CellTracker Green samples showed a marked difference from the Rose Bengal samples, consistent with literature that suggests the two methods differ. Fluctuating populations of foraminifera in fossil samples can be interpreted as changes in local or global climate. This study stands as a modern analog for fossil foraminiferal assemblages, and provides important information to help interpret paleoenvironmental conditions related to seasonality by defining seasonally and geographically distinct species assemblages.
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Hurley, John Vincent. "Late-middle Eocene glacioeustacy : evidence from stable isotopes and foraminifera of the the [sic] Planktonic foraminiferan zone P14 (Truncorotaloides rohri zone), Mossy Grove Core, Hinds County, Mississippi." Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1117851.
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Glacioeustatic control of a late-middle Eocene oxygen isotope record is evident from the comparison of such a record with an independent proxy for sea-level. The data, δ18O and planktonic:benthic foraminifera ratios, were determined from samples of the Mossy Grove Core, Hinds County, Mississippi. The temporal order of magnitude for the glacioeustatic cycles, while smaller than two other orders of sea level change identified from this sedimentary package, is comparable to those associated with Milankovitch cycles. Refinement of the sample interval’s sequence statigraphy recognizes a Healing Phase Unit and allowed for identification of the time stratigraphic condensed section. Identification of the condensed section allows for the correlation of this sequence to other sections in the Gulf Coast.<br>Department of Geology
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Vicedo, Vicedo Vicent. "Morfoestructura de los géneros cretácicos de los Rhapydioninidae (Foraminifera)." Doctoral thesis, Universitat Autònoma de Barcelona, 2008. http://hdl.handle.net/10803/3447.
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Los rapidionínidos representan un elemento importante, diverso y abundante en las comunidades de macroforaminíferos porcelanados de aguas poco profundas del Cretácico medio y superior. Su morfología general es muy similar, por lo que es necesario un estudio morfológico detallado para distinguir los géneros y especies en el interior de los diferentes grupos implicados. La revisión de los taxones aquí estudiados ha permitido eliminar ciertas contradicciones e inconsistencias que se han dado en la literatura del grupo, incrementar su potencial valor como fósiles guía y entender mejor el significado de su distribución paleogeográfica. En particular, el uso del nombre genérico de Pseudedomia Henson, 1948, (especie tipo P. multistriata, Maastrichtian) para designar especies del Ciclo de Maduración de la Comunidad (Global Community Maturation cycle, Hottinger 2001) previo, como "P." drorimensis Reiss et al., 1964, (Cenomaniense) o la supuesta sinonimia entre el género caribeño Raadshoovenia guatemalensis Van den Bold, 1946, (de edad supuestamente Paleoceno) y el género tetisiano Cuvillierinella salentina Papetti y Tedeschi, 1965, (Cretácico superior) han sido la causa de las dificultades en la comprensión de la evolución de la familia Rhapydioninidae en el tiempo y el espacio. <br/>Para llevar a cabo la revisión de los taxones, se han muestreado las localidades tipo o, cuando ha sido imposible, las localidades equivalentes siempre lo más cercanamente posible a las localidades tipo. En México, para el muestreo se han seguido las indicaciones y descripciones estratigráficas de Pêcheux (1984) y Michaud (1987). En España, se han considerado los trabajos de Martín-Chivelet (1993) para la Cordillera Bética y Calonge (1989) para la Cordillera Ibérica. En Grecia se han seguido los trabajos de Fleury (1974), mientras que el material de Italia fue recolectado por Mariano Parente en los Apeninos. Todos los rapidionínidos proceden de sedimentos extraordinariamente poco profundos. Por consiguiente, su restringido nicho ecológico dificulta una correlación precisa con la escala cronoestratigráfica en general y con la escala biostratigráfica basada en biozonaciones de orbitoídidos en particular. En consecuencia, algunas de las conclusiones taxonómicas dadas a nivel específico se deben considerar provisionales o tentativas. Los resultados de este trabajo confirman en gran medida las observaciones realizadas por Fleury y Fourcade en su trabajo de 1990, el único trabajo publicado en el que se da una visión general del grupo de los rapidionínidos desde que Henson publicara, en 1948, su monografía.<br>The rhapydioninids represent an important, diverse and abundant element in the shallow-water communities of porcelaneous foraminifera of the Middle and Late Cretaceous. Their general morphology is very similar and called for a careful morphological analysis in order to distinguish the genera and the species within the different groups involved. The revision of the relevant taxa given here permits to eliminate contradictions and inconsistencies in the current literature, to enhance their potential as biostratigraphic index fossils and to understand the significance of their paleogeographic distribution. In particular, the use of the generic name Pseudedomia Henson, 1948, (type species: P. multistriata, Maastrichtian) for species belonging to the previous Global Community Maturation cycle (Hottinger, 2001), such as "P." drorimensis Reiss et al., 1964, (Cenomanian) or the supposed synonymy of the Caribbean Raadshoovenia guatemalensis van den Bold, 1946, (said to be of Paleocene age) with the Tethyan Cuvillierinella salentina Papetti and Tedeschi, 1965, (Late Cretaceous) have produced considerable difficulties to understand the evolution of the rhapydioninid family in time and space. <br/>In order to revise the various taxa involved, their type localities or as close equivalents as possible where sampled. In Mexico the stratigraphical descriptions and indications of Pêcheux (1984) and Michaud (1987) were followed. In Spain, we could relay on the work of Martin-Chivelet (1993) for the Betic Cordillera and of Calonge (1989) for the Iberian range. In Greece we founded our sampling on the papers of Fleury (1974), whereas in Italy Mario Parente collected suitable material for our research from the Apennines. All rhapydioninids are found in sediments with an extremely very shallow facies. Thus, their restricted ecological range often hampers a precise correlation with the chronostratigraphic time scale in general and with the ecologically closest biostratigraphic zonation based on orbitoids in particular. Therefore, some of the taxonomic conclusions on the species level must be considered as provisional or tentative. The results of the revisions given here confirm to a large extent the views expressed by Fleury and Fourcade in their paper of 1990, the only comprehensive overview on the group to be found in literature since Henson's monograph in 1948.
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Bryan, Sean Patrick. "Calibration of trace element paleoceanographic proxies in benthic foraminifera." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1446083.
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Aze, Tracy. "Cope's rule and macroevolution of Cenozoic macroperforate planktonic foraminifera." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/22350/.
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Abstract A comprehensive phylogeny of macroperforate planktonic foraminifer species of the Cenozoic Era (~65 million years ago to present) is presented. The phylogeny is developed from a large body of palaeontological work that details the evolutionary relationships and stratigraphic (time) distributions of species-level taxa identified from morphology (‘morphospecies’). Morphospecies are assigned to morphogroups and ecogroups depending on test morphology and inferred habitat, respectively. Because gradual evolution is well documented in this clade, instances of morphospecies intergrading over time have been identified, allowing the elimination ‘pseudospeciation’ and ‘pseudoextinction’ from the record and thereby permit the construction of a more natural phylogeny based on inferred biological lineages. Each cladogenetic event is determined as either budding or bifurcating depending on the pattern of morphological change at the time of branching. This lineage phylogeny provides palaeontologically calibrated ages for each divergence that are entirely independent of molecular data. The tree provides a model system for macroevolutionary studies in the fossil record addressing questions of speciation, extinction, and rates and patterns of evolution. Specifically for this thesis the phylogenies provide a statistically robust framework for testing Cope’s rule (the evolutionary trend towards larger body size along a lineage). Eleven case studies were selected at random from all possible Neogene lineages and the mean areas of ancestor and descendant populations were compared. Over 6000 measurements were taken from 30 lineages and the resulting data show that Neogene macroperforate planktonic foraminifera do not support Cope’s rule with only 48% of the ancestor-descendant population comparisons demonstrating an increase in mean area. The size analysis illustrates that the most robust method for testing Cope’s rule is to compare ancestor-descendant populations from the beginning and end of evolutionary lineages as these are the least affected by temporal sampling biases.
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Kelham, Angela. "Investigation into the post-mortem transport of benthic foraminifera." Thesis, University of Hull, 2011. http://hydra.hull.ac.uk/resources/hull:5473.
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Palaeoenvironmental reconstruction using foraminifera relies on the assumption that assemblages reflect the ecological conditions at the time of deposition. However, the distribution of taxa can be greatly affected by transport and reworking of tests. This is particularly important in high energy environments such as submarine canyon and fan systems, which are major pathways for sediment transported from the continental shelf to the abyssal plain. Traditionally, these assemblages have been abandoned as hopelessly taphonomically corrupted, but it is possible that these assemblages contain useful hydraulic information. This project aims to develop the fundamental concepts needed to extract this information, via a series of classical particle hydraulics experiments on empty tests in static water and unidirectional currents. Hyaline foraminifera have been selected for these experiments, as they are the most abundant tests found in shelf and upper-slope environments and consequently are most likely taxa to be entrained into gravity flows. Static water experiments have shown that settling velocities are significantly different between taxa, meaning that assemblages are likely to fractionate according to species during transportation. Settling velocities range from 0.01 to 0.06 ms-1 with larger specimens falling faster than smaller ones. Elphidium crispum exhibited the fastest average settling velocity of 0.03 ms-1 while Planorbulina mediterranensis fell with the lowest average settling velocity of 0.01 ms-1. The occurrence of spatial separation of taxa within a single flow is directly tested using a flume where a spatially waning turbidity current is simulated by a saline density flow. Results show that the slowly settling tests such as P. mediterranensis and Cibicides lobatulus remain suspended in the current for longer, and are thus transported further than more rapidly settling taxa such as E. cripsum and Ammonia beccarii. The experiments have shown that there are significant statistical differences in settling velocity of foraminiferal species and this does result in significantly distinct travelling distances between species in a turbidite. This information is related to the oceanic environment in the Gulf of Cadiz. The signal of fractionation is then identified in core data from Trinidad supplied by Ichron showing that useful assemblage data can be extracted to interpret the depositional environment.
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Evans, John Rhys. "Late Neogene agglutinated foraminifera from the central Arctic Ocean." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267751.
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Kaminski, Michael Anthony. "Cenozoic deep-water agglutinated foraminifera in the North Atlantic." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/55312.
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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), February 1988.<br>Vita.<br>Includes bibliographical references (p. 243-259).<br>by Michael Anthony Kaminski.<br>Ph.D.
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Rode, Sandra Lee 1955. "FORAMINIFERA AS A TEST OF HERITABILITY OF SPECIATION POTENTIAL." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276479.
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If species selection shapes the history of clades, we should be able to detect its impact within well-established monophyletic descent groups. We should find that high rates of speciation/extinction are heritable. Demonstrating that high speciation/extinction rates have not been transmitted along known lines of descent would prove that species selection had not played an important role with the descent group under study. I have screened speciation rates within the Cenozoic planktonic foraminifera for heritability. Neither modified parent-offspring tests nor rank concordance tests reveal inheritance of this trait.
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Pazio, Magdalena. "The late Ediacaran Agglutinated Foraminifera from Finnmark, Northern Norway." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-183994.
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Stewart, Duncan Ross McIver. "Evolution of Neogene globorotaliid foraminifera and Miocene climate change." Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/2bd17901-2015-41b6-b43a-acb79c9cdf44.
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Pettit, Laura Rachel. "The effects of ocean acidification on modern benthic foraminifera." Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/3465.
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Ocean acidification may cause biodiversity loss, alter ecosystems and impact food security, yet uncertainty over ecological responses to ocean acidification remains considerable. Most work on the impact of ocean acidification on foraminifera has been short-term laboratory experiments on single species. To expand this, benthic foraminiferal assemblages were examined across shallow water CO2 gradients in the Gulf of California, off the islands of Ischia and Vulcano in Italy and off Papua New Guinea. Living assemblages from the Gulf of California did not appear to show a response across a pH range of 7.55 – 7.88, although the species assemblage was impoverished in all locations and the dead assemblage was less diverse at the lowest pH sites where there was evidence of post mortem dissolution. At Vulcano, the small macroalga, Padina pavonica, did not protect calcareous foraminifera from the adverse effects of ocean acidification. Calcareous taxa disappeared from the assemblage and were replaced by agglutinated foraminifera as mean pH reduced from 8.19 to 7.71. Settlement of benthic foraminifera onto artificial collectors off Vulcano was adversely affected in the acidified water, with few species as pCO2 increased and evidence of post-mortem dissolution. The foraminiferal tests, collected off Papua New Guinea, had lower δ11B as mean pH decreased from 7.99 – 7.82 for small (250 – 500 µm) Amphistegina lessonii, but not for A. lessonii or Calcarina spengleri >500 µm. In the larger foraminifera, photosynthetic activity by symbionts may begin to dominate the boron isotopic signature. Overall, the responses of foraminiferal assemblages to ocean acidification are complex, but there was an overall reduction in species diversity in infaunal, epifaunal and epiphytic assemblages as pCO2 increased. This raises serious concerns for the survival of shallow water calcareous benthic foraminifera as the oceans continue to acidify, with implications for benthic ecosystems and inorganic carbon cycling.
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Bowen, Powell Jacqueline. "Larger Foraminiferal Biostratigraphy, Systematics And Paleoenvironments of The Avon Park Formation and Ocala Limestone, Highlands County, Florida." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/288.
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This study investigates the use of larger foraminifera in determining the biostratigraphy of the Avon Park Formation and the Ocala Limestone in central Florida. Sedimentary rocks of the Avon Park Formation are the oldest exposed deposits in the state of Florida, and together with the Ocala Limestone comprise a part of the confining unit of the Floridan Aquifer, a major source of Florida’s water supply. Material from the ROMP 29A core collected by the U. S. Geological Survey was evaluated and compared to previous studies of the biostratigraphy of the formations. The larger foraminifera of the Avon Park Formation were examined in thin section, and those of the Ocala Limestone were free specimens. The larger foraminifera from both units were described and identified, and the biostratigraphy determined. The morphological features of the larger foraminifera of the Ocala Limestone were measured and analyzed at various depths within the ROMP 29A core. The Avon Park Formation contains predominantly the shallow-water, conical foraminifera Fallotella cookei, Fallotella floridana, Pseudochrysalidina floridana, Coleiconus christianaensis, Coleiconus sp. A, Coskinolina sp. A, Coskinolina sp. B, Fallotella sp. A, Fallotella sp. B, Fabularia vaughani and larger miliolids. The Ocala Limestone contains a different, deeper water assemblage that included the larger foraminifera Heterostegina ocalana, Lepidocyclina ocalana varieties, Lepidocyclina chaperi, Lepidocyclina pustulosa, Nummulites willcoxi, Nummulites striatoreticulatus, Nummulites floridensis and Pseudophragmina spp. A, B, and C. The age of the Avon Park Formation was corroborated by the occurrence of the biomarker echinoid Neolaganum dalli as Eocene, and the Ocala Limestone also contained Eocene larger foraminifera with Eocene to possibly Oligocene calcareous nannofossils. The distribution of the larger foraminifera of the Avon Park Formation was correlated with the subtidal and peritidal zones of the continental shelf. Analyses of variance showed that the changes in measurements of the morphology in Heterostegina ocalana, Lepidocyclina spp. and Nummulites spp. were correlated with change in the depositional environments.
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Julian, Meaghan Elizabeth. "Benthic foraminiferal faunal changes during the Eocene/Oligocene climate transition at Ocean Drilling Program (ODP) sites 1209A and 1211A from the Shatsky Rise, central Pacific Ocean." Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1519.
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Edwards, Robin James. "Late Holocene relative sea level change and climate in southern Britain." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/1056/.
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Groves, Daniel James. "HOLOCENE FORAMINIFERAL ASSEMBLAGE AND STABLE ISOTOPE ANALYSIS FOR THE GERLACHE STRAIT, ANTARCTIC PENINSULA." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/theses/1642.
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The Antarctic Peninsula is one of the fastest warming regions on the planet. In the past 50 years, the temperature has increased by more than 2⁰C, leading to the retreat of large areas of the ice shelves fringing the Antarctic Peninsula. Recent environmental changes in the Antarctic Peninsula are well documented by meteorological and remote sensing data, but the behavior of the Holocene atmosphere-ocean-cryosphere system is not well understood. In this study foraminifera are used as a proxy for Holocene oceanographic conditions in the Gerlache Strait, western Antarctic Peninsula. The most abundant foraminifera identified in this study include the agglutinated taxa Miliammina arenacea and Paratrochammina lepida, which are associated with cold, saline water masses and periods of high sea-ice production. The most abundant calcareous species identified is the opportunistic Fursenkoina spp., which is associated with ice-proximal conditions and fresh water input due to glacial melting. Deglaciation of the Gerlache following the Last Glacial Maximum is indicated by the appearance of foraminifera and diatoms at ~7700 years BP. The Post-Deglaciation period is characterized by high frequency variation in foraminiferal assemblages between abundant agglutinated and calcareous taxa, indicating unstable glacial conditions. The beginning of the Mid-Holocene Climactic Optimum (MHCO) is indicated by a substantial decrease in sedimentation rates and a shift to more stable foraminiferal assemblages. A decline in diatom abundance and the absence of calcareous foraminifera indicates a glacial readvance at 6030 years BP. At 4470 years BP the calcareous taxa including Fursenkoina spp. become dominant, indicating glacial retreat and input of fresh water into the water column. After 3240 years BP agglutinated taxa are once again dominant and calcareous taxa absent. This marks the beginning of the Neoglacial period and the presence of colder, more saline shelf waters in the Gerlache Strait. Stratification of the water column is apparent during the Post-Deglaciation period and the latter part of the MCHO. A difference in δ18O values of >0.5 per mille between benthic and planktonic foraminifera indicates the presence of a less saline surface water layer which may be the result of freshwater input due to glacial melting and an estuarine circulation regime.
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Arriaga, Cavalieri Maria Eugenia. "Patrones de supervivencia y recuperación de los macroforaminíferos después de la extinción en masa del límite Cenomaniense-Turoniense." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/394041.
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Los macroforaminiferos constituyen un grupo de organismos k-estrategas de abundante presencia en los ambientes de plataformas pocos profundas, tanto en la actualidad como en el registro fósil, siendo a su vez uno de los grupos más susceptible a cambios en el medio am¬biente.
Durante la transición Cenomanience – Turoniense (CTB), la cual coincide con un epi¬sodio global de depositación de sedimentos ricos en materia orgánica (Evento Anóxico 2 o Evento Bonarelli), los macroforaminíferos que poblaban las plataformas carbonatadas fueron dramáticamente afectados por el drástico cambio en las condiciones ambientales. Dicho cam¬bio generó la octaba mayor extinción de organismos marinos que se conoce, acabando con la comunidad de macroforaminíferos correspondiente al Ciclo de Maduración Global del Cretáci¬co medio (GCMC). En esta tesis se discuten los patrones de recuperación de los foraminíferos luego de esta extinción.
El trabajo ha sido realizado en dos paleobioprovincias contiguas: la del Tetis central, que aflora en los Apeninos meridionales, y la Pirenaica, que aflora en los Pirineos meridionales (Unidad Surpirenaica Central). En los Pirineos, al igual que en la mayoría de plataformas a nivel mundial, las aguas que cubrían las plataformas poco profundas del Cenomaniense sufrieron un proceso de eutrofización que condujo a la desaparición de los organismos productores de carbonato, trayendo como consecuencia el cese de la sedimentación carbonatada. Esta falta de sedimentación tiene como consecuencia un hiato sedimentario, el cual que se registra pre¬vio a la inundación de la plataforma (drowning platform). Mientras que la Plataforma Apení¬nica mantuvo una sedimentación carbonatada somera durante el tránsito Cenomaniense-Tu¬roniense, y a pesar haber sido colonizada por organismos cianobacteriales, algunos pequeños foraminíferos bentónicos fueron capaces de sobrevivir.
Este estudio sugiere que, a pesar de las diferencias depositacionales y paleogeográficas entre las dos áreas estudiadas, los patrones de recuperación fueron muy similares, de la si¬guiente manera: 1) la información genética de las formas k-estrategas se perdió en la extinción en masa; sin embargo cierta “herencia” se mantiene en las pequeñas formas oportunistas de los géneros Nezzazatinella, Cuneolina, Dictyopsella y Rotorbinella sobrevivientes a la extin¬ción. 2) la calibración cronoestratigráfica de las secciones de los Apeninos meridionales, reali¬zada mediante datos de estratigrafía isotópica de Carbono y Estroncio, indican que después de la crisis del CTB las primeras formas nuevas aparecen en el Turoniense inferior (parte superior) y Turoniense medio, representadas por las especies Moncharmontia apenninica y Pseudocy¬clammina spharoidea; aunque no es sino hasta el Turoniense medio-superior que aparecen Scandonea samnítica y Reticulinella kaeveri, formas relativamente más complejas. 3) en los
Pirineos, la reaparición de fauna somera de foraminíferos en el registro fósil no ocurre has¬ta el Turoniense medio-superior, luego de la recuperación de la sedimentación carbonatada, con la presencia de las especies Moncharmontia apenninica y Pseudocyclammina spharoidea además de las formas “heredadas” del Cenomaniense, apareciendo luego géneros complejos como Eofallotia. 4) en ambas áreas el inicio del “Ciclo de Maduración Global de la Comunidad de macroforminíferos del Cretácico superior fue aparentemente simultánea. No obstante, a partir del Turoniense medio-superior se manifiesta ya un cierto provincialismo, a través de la presencia de los géneros Scandonea y Reticulinella en la paleobioprovincia del Tethys central y representantes del grupo de los meandropsínidos en la paleobioprovincia pirenaica, provin¬cialismo que se será mucho más acentuado en las etapas posteriores de ciclo de maduración.<br>Larger foraminifera are a k-strategists group extremely abundant in shallow water plat¬form environments, both in the recent and the fossil record. They represent one of the most sensitive marine organisms to environmental perturbations.
During the Cenomanian-Turonian Boundary (CTB) interval, coinciding with a widespread episode of organic-rich sediments deposition (Oceanic Anoxic Event 2 or Bonarelli event), the larger foraminifera inhabiting the shallow environment were dramatically affected by a major paleoenvironmental conditions change. Such event finished with the middle Cretaceous Glo¬bal Community Maturation Cycle (GCMC). In this work we discuss the post-extinction recovery pattern.
This works has been carried out in two neighboring paleoprovinces: Central Tethys, which outcrop at the southern Appenines, and the Pyrenean, outcrop located at the southern Pyrenees (Central Sud-pyrenean Unit). In the Pyrenees, like in most of the platforms, the water layer suffered an eutrophication process that leads demise the carbonate producer organisms, causing a stop on carbonate sedimentation. Such lack on sedimentation generates a sedimen¬tary hiatus perceptible in the stratigraphic record before the drowning episode. While the platform from southern Apennines was able to keep up on shallow carbonate sedimentation, and despite the colonization of cyanobacteria organisms, some small foraminifera were capa¬ble to survive.
Here is suggest that even though the paleogeographic and depositional differences bet¬ween the studied areas, both present similar recovery patterns in the fallowing way: 1) The genetic information necessary for sustaining a k-strategy was lost with the extinction, but the “legacy” of larger foraminifera survived in the small r-strategist forms of Nezzazatinella, Cu¬neolina, Dictyopsella and Rotorbinella survivor genus. 2) chronostratigraphic calibration of Apenninic sections made by Strontium and Carbon Isotopic Stratigraphic data, indicates that the firth “newcomers ” appears during the upper part of lower Turonian with Moncharmontia apenninica and Pseudocyclammina spharoidea new species; but is not until middle-upper Tu¬ronian that more complex forms appears with Scandonea samnítica and Reticulinella kaeveri species. 3) In the Pyrenees, the shallow foraminiferal fauna reenter during the mid-upper Tu¬ronian after the carbonate sedimentation retrieval, represented by Moncharmontia apennini¬ca and Pseudocyclammina spharoidea species together with the “legacy” forms from Cenoma¬nian age; then also appear more complex genus as Eofallotia. 4) It seems like in both areas the Global Community Maduration Cycle of upper Cretaceous began simultaneously. However, from the middle-upper some sort of provincialism is noticeable with the presence of Scando¬nea and Reticulinella genus in the central Tethys, while the firth forms of meandropsinids are
showns up for the Pyrenean realm, such paleoprovincialism considerably emphasizes during the latter stages of upper Cretaceous GCMC.
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Cheng, Jie. "Paleoenvironmental Reconstruction of Florida Bay, South Florida, Using Benthic Foraminifera." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/179.
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Efforts that are underway to rehabilitate the Florida Bay ecosystem to a more natural state are best guided by a comprehensive understanding of the natural versus human-induced variability that has existed within the ecosystem. Benthic foraminifera, which are well-known paleoenvironmental indicators, were identified in 203 sediment samples from six sediment cores taken from Florida Bay, and analyzed to understand the environmental variability through anthropogenically unaltered and altered periods. In this research, taxa serving as indicators of (1) seagrass abundance (which is correlated with water quality), (2) salinity, and (3) general habitat change, were studied in detail over the past 120 years, and more generally over the past ~4000 years. Historical seagrass abundance was reconstructed with the proportions of species that prefer living attached to seagrass blades over other substrates. Historical salinity trends were determined by analyzing brackish versus marine faunas, which were defined based on species’ salinity preferences. Statistical methods including cluster analysis, discriminant analysis, analysis of variance and Fisher’s α were used to analyze trends in the data. The changes in seagrass abundance and salinity over the last ~120 years are attributed to anthropogenic activities such as construction of the Flagler Railroad from the mainland to the Florida Keys, the Tamiami Trail that stretches from the east to west coast, and canals and levees in south Florida, as well as natural events such as droughts and increased rainfall from hurricanes. Longer term changes (over ~4000 years) in seagrass abundance and salinity are mostly related to sea level changes. Since seawater entered the Florida Bay area around ~4000 years ago, only one probable sea level drop occurring around ~3000 years was identified.
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Toomey, Heidi M. "Chlorophyll Fluorescence and Thermal Stress in Archaias angulatus (Class Foraminifera)." Thesis, University of South Florida, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1549223.
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<p> Benthic foraminifers that host algal symbionts are similar to corals in that they rely on their algal endosymbionts for their energy needs, calcify prolifically, and are sensitive to changes in environmental conditions. They are abundant in the benthos of coastal coral-reef areas and are found throughout the tropical and subtropical regions. Pulse Amplitude Modulated (PAM) chlorophyll fluorometry and chlorophyll a extraction techniques were used to quantify and compare the photosynthetic responses of the benthic foraminifera, <i> Archaias angulatus</i> and their isolated endosymbionts, <i>Chlamydomonas hedleyi</i>, to short-term changes in temperature. Maximum quantum efficiency (Fv/Fm) and rapid light curves (RLCs), from which relative electron transport rates (rETR) of photosystem II (PSII) were derived, were investigated over a thermal range from 4.4° to 33.9 °C in three experiments that were 7 to 31 days in duration. Typical mean yields (Fv/Fm) for healthy holobionts (symbionts in hospite) were 0.6 - 0.7, and for isolated symbionts 0.5 - 0.6. Chronic photoinhibition, indicated by significant decreases in Fv/Fm, occurred at temperatures above 31.0°C; there was minimal reduction in efficiency in cooler treatments. The trends between holobiont and symbionts were very similar in all of the photophysiological parameters measured [yield, photoefficiency (á), ETRmax and minimum saturating irradiance (Ek)] and supported the temperature range findings in terms of the tolerance of the specimens in the low temperatures up to 31.0 °C. For all photochemical measurements assessed, the holobiont values tended to be somewhat higher than those for the symbionts, with the exception of Ek, possibly indicating a tight coupling in the host-symbiont response during photosynthesis. Chlorophyll a (ìg/foram) was negatively correlated with temperature (r = -0.37, p < 0.001) in Experiments 1 and 2. However, in all 3 experiments, chlorophyll a was variable, suggesting a high degree of individual variability in <i>A. angulatus</i> and the ability to acclimate. Some differences observed among treatments may be related to differences in seasons when the specimens were collected and in length of time in culture prior to experiments. Holobiont median rETR light curve trends and photophysiological derived parameters recorded median Ek ranges of ~100-150 ìmol photons m<sup>-2</sup> s<sup>-1</sup>, observed ETR<sub>max</sub> light intensities of ~200 ìmol photons m-2 s-1 and photoinhibition, induced by increasing irradiance intensities, which occurred > 500 ìmol photons m<sup>-2</sup> s<sup>-1</sup>. These light curve trends and derived parameters generally supported previous photosynthesis O<sub>2</sub> and CO<sub>2</sub> gas production studies of A. angulatus. The differences in responses associated with acclimation should be considered in design of future experimental studies. This was the first known physiological study of the viable temperature range and photobiology of A. angulatus using chlorophyll fluorometry methods. Though commonly found in Caribbean and Atlantic waters ranging from 14.0 – 31.0 °C, these results indicate a wider thermal-tolerance range for A. angulatus than was previously known.</p>
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Rae, James W. B. "Boron isotopes in benthic foraminifera : measurement, calibration and glacial CO2." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.544334.
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Ross, Benjamin James. "Responses to Chemical Exposure by Foraminifera: Distinguishing Dormancy From Mortality." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4397.
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The Deepwater Horizon blowout in 2010 released an estimated 4.9 million barrels of crude oil into the Gulf of Mexico in the 83 days between the initial explosion and the capping of the well. Response included extensive use of Corexit© oil dispersant. Although South Florida was spared exposure by currents, this event highlights the need for effective bioassay organisms for coral reefs. Amphistegina spp. are benthic foraminifers that host diatom symbionts in a relationship similar to that of coral and their zooxanthellae. Amphistegina spp. occur abundantly in reef communities nearly worldwide, are easily collected and maintained in culture, and are a key component of the FoRAM Index, a indicator of water and sediment quality in coastal waters. The major goals of this project were to develop protocols to test the acute and chronic responses of A. gibbosa to potentially toxic organic chemicals.
Initial objectives were to determine lethal concentrations and effects ranges, as defined by the US Environmental Protection Agency, of two components of the Corexit© dispersants. Preliminary experiments indicated that many specimens exposed to propylene glycol (v/v) at concentrations of 2% or higher appeared to be dead following 48-hour exposure, resulting in apparent LC50 of 3% and an initial effects range of 2-4%. When placed in filtered seawater, after 72-hours the observed LC50 was 6%. All parameters assessed, including sub-lethal chronic effects (differences in growth and visible responses after 40 days), revealed an effects range of 0.5% to 12%, above which there was 100% mortality. For 2-butoxyethanol, the apparent LC50 after 48-hour exposure was 0.2%; after 72-hour recovery the LC50 was 1%. In all experiments, a 72-hour recovery period was sufficient to determine acute effects. A key discovery was the observation of inactivity during exposure to toxic substances, followed by recovery when placed in filtered seawater. This observation indicates the potential for dormancy in adult foraminifers exposed to toxic substances that has not previously been reported.
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Dagher, Marcelle Bou. "Lower Eocene shelf smaller foraminifera a comparative inter-regional study." Thesis, University College London (University of London), 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260930.
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Hathorne, Edmund Charles. "The trace element and lithium isotope composition of planktonic foraminifera." Thesis, Open University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417477.
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Bates, Stephanie. "Barium uptake by foraminifera : understanding past and present ocean processes." Thesis, University of Bristol, 2016. http://hdl.handle.net/1983/c12eed98-50c4-421f-8a79-af2f292fa971.
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Oceanic barium can provide multiple insights into the marine environment, an important facet of the climate system. Dissolved barium is removed from near-surface seawater in association with biological productivity and is returned at depth via remineralisation and barite dissolution, imparting a nutrient-like profile similar to that of carbonate alkalinity and silica. Due to the similarity in their distributions, seawater barium and alkalinity display a positive linear relationship globally and different water masses have distinct barium-alkalinity compositions. Benthic foraminiferal Ba/Ca ratios can thus be used as a proxy for past ocean circulation and alkalinity, but this may be complicated by additional environmental influences, particularly in non-pelagic settings. In addition, a specific barium partition coefficient may be required for each individual species. Glacial-interglacial changes have been successfully measured using benthic Ba/Ca ratios but many possible applications have yet to be explored to the same extent, such as comparisons between interglacial periods. Barium isotope ratios (δ138Ba) can also be used to enhance our understanding of the marine environment, but because this is a relatively new technique there is still much to be learned regarding the oceanic distribution of barium isotopes and the relationship between seawater and foraminifer δ138Ba is not yet known. An essential prerequisite to measuring either Ba/Ca or δ138Ba ratios in foraminifera is the removal of particulate barite from their inner and outer surfaces. Although a cleaning technique has been established, this has sometimes increased foraminiferal Ba/Ca ratios, perhaps due to the preferential dissolution of low-barium calcium carbonate. During this project these topics were investigated using sediment cores from the southeast and southwest Atlantic Ocean dated to the Holocene and Marine Isotope Stage 5e (MIS 5e, part of the last interglacial period), as well as seawater and foraminifer samples of modern age from the tropical North Atlantic. Ba/Ca ratios in a continental shelf sediment core remain approximately constant despite apparent fluctuations in primary productivity, suggesting that the Ba/Ca proxy can reliably be used as a proxy for ocean circulation even in relatively shallow and productive regions. The effect of dissolution on Ba/Ca could not be assessed due to the absence of dissolution effects in this sediment core. New barium partition coefficients are presented for the benthic foraminifer species Melonis barleeanus, Oridorsalis umbonatus and Uvigerina peregrina. These are offset from one another, highlighting the potential importance of using species-specific partition coefficients. In other sediment cores from the southwest Atlantic, MIS 5e Ba/Ca ratios are on average significantly higher than those of the Holocene. This may be due to a ‘stagnation event’ in Antarctic Bottom Water (AABW) formation during MIS 5e which led to a build-up of dissolved barium in AABW. In samples from the tropical North Atlantic Ocean, seawater δ138Ba appears to be controlled by conservative mixing at depths below ~500 m, with additional non-conservative controls in the upper ~500 m. δ138Ba ratios in the planktic foraminifer Orbulina universa are consistently isotopically lighter than seawater, but the magnitude of this offset is variable. This variability may be due to morphotype-specific vital effects on δ138Ba ratios. Although cleaning tests provide indirect evidence for barite removal, the impact of cleaning on Ba/Ca ratios remains variable and the cause of this variability remains an open question. Collectively, the findings presented here have implications for the uses of Ba/Ca and δ138Ba ratios as palaeoceanographic proxies, as well as for the possible mechanisms of climatic variability in MIS 5e and the Holocene.
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Austin, Heather Anne. "The biology and ecology of benthic foraminifera inhabiting intertidal mudflats." Thesis, University of St Andrews, 2003. http://hdl.handle.net/10023/7099.
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Benthic foraminifera inhabiting the mudflats of the Eden Estuary, NE Scotland, exhibited a single annual peak in abundance at both high (270 individuals 10 cm⁻²) and low shore (210 individuals 10 cm⁻²) intertidal sampling stations during June 2000. The increased total abundance coincided with reproduction in the two dominant foraminiferal species Elphidium williamsoni (May) and Haynesina germanica (June) at both sites. Benthic diatom biomass, measured as chlorophyll c, peaked at the high intertidal site during March and April 2001 (36 and 37 mg m cm⁻², respectively) and at the low intertidal site in June2000 (45 mg m cm⁻²). The high intertidal foraminiferal populations appeared to display a lagged response to increases in chlorophyll c. Multivariate statistics suggest that abiotic factors control the abundance of foraminifera at the high intertidal site. At the low intertidal site, total foraminiferal abundance demonstrated an almost immediate response to increased chlorophyll c and multivariate statistics suggested biotic factors are more important in controlling foraminiferal species abundance here. Ingestion rates of ¹³C-Iabelled benthic diatoms over a five-day experimental period were high (e.g. enrichment values for Elphidium were recorded as 687 ± 121 % after 1 day) in intertidal benthic foraminifera. Laboratory observations of E. williamsoni demonstrated rapid asexual reproduction (within 3 days) and growth rates of up to 14 µm day⁻¹ were estimated. Three benthic foraminiferal species E. williamsoni, H germanica and E. oceanensis ingest motile benthic diatoms as a food resource on the intertidal mudflats of the Eden Estuary. Novel application of natural abundance stable isotope (δ¹³C and δ¹⁵N) techniques demonstrated the trophic position of intertidal benthic foraminifera, confirming that they largely ingest and assimilate organic matter derived from benthic diatoms. Foraminifera have largely been overlooked in meiofaunal studies, but play a significant role in the rapid transfer of autotrophic carbon to higher trophic levels within benthic marine food webs.
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Oluyemi, Aturamu Adeyinka. "The palaeontology of Bering Sea foraminifera from the Late Quaternary." Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/33161.
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The taxonomy of benthic foraminifera recovered from 160 core samples over depth 20.59 m and representing the past ~597 Kyr (sedimentary deposit of the Tarantian and Ionian stages) at Bowers Ridge, Bering Sea IODP site U1342, includes some 52 species from 41 genera and 22 families: these species are given formal taxonomic treatment with detailed illustration. A further 16 species are discussed in open nomenclature. Foraminifer assemblages are dominated by species of Takayanagia delicata, Uvigerina bifurcata, Islandiella norcrossi and Alabaminella weddellensis accounting for more than 58 % of all specimens recovered. In addition to their taxonomic identification, this study interrogates the relationship between benthic foraminifera and interpreted changes in oxygen concentration and productivity during a series of late Quaternary glacial– interglacial cycles at site U1342. In particular, the species Bolivina spissa (Cushman) – thought to record changes in seabed oxygen level, shows no correlation between test pore density and interpreted bottom water oxygen level (BW-O2), suggesting that oxygen is not the sole driver influencing the distribution and morphology of this species. Further assessment of the total foraminiferal assemblages at site U1342 - using the sedimentological context and the proportion of deep infaunal species as a proxy for low oxygen conditions at the seabed, and shallow infaunal species as a proxy for a welloxygenated seabed, identify eight broadly defined temporally successive benthic foraminiferal intervals through the sampled core. Three of these intervals, between depths 0 - ~5.40, ~ 6.50 - 9.00 and ~16.90 - 18.67 m-CCSF, signal a well-oxygenated sea bed, whilst the other five intervals suggest increased phytodetritus flux to the seabed, coupled with variations in seabed oxygen level. In general, there is no clear connexion between these intervals and the glacial-interglacial oscillation at the site during the past ~597 ka, suggesting that ecological influences on foraminiferal distribution at Bowers are complex.
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Beer, Christopher James. "Planktic foraminifera, ocean sediments and the palaeo-marine carbonate system." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/208361/.
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Ishman, Scott E. "Quantitative analysis of Antarctic benthic foraminifera : application to paleoenvironmental interpretations /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487683049375259.
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Schmuker, Barbara. "Recent planktic foraminifera in the Caribbean sea : distribution, ecology and taphonomy /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13559.
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Mallon, Jürgen [Verfasser]. "Benthic Foraminifera of the Peruvian and Ecuadorian Continental Margin / Jürgen Mallon." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/1020284048/34.
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Lorenz, Andrea. "Variability of benthic foraminifera north and south of the Denmark Strait." [S.l.] : [s.n.], 2005. http://e-diss.uni-kiel.de/diss_1646/d1646.pdf.
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Marchitto, Thomas Mathew. "Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/55333.
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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), February 2000.<br>Includes bibliographical references.<br>Benthic foraminiferal δ13C, Cd/Ca, and Ba/Ca are important tools for reconstructing nutrient distributions, and thus ocean circulation, on glacial-interglacial timescales. However, each tracer has its own "artifacts" that can complicate paleoceanographic interpretations. It is therefore advantageous to measure multiple nutrient proxies with the aim of separating the various complicating effects. Zn/Ca is introduced as an important aid toward this goal. Benthic (Hoeglundina elegans) Cd/Ca ratios from the Bahama Banks indicate that the North Atlantic subtropical gyre was greatly depleted in nutrients during the last glacial maximum (LGM). A high-resolution Cd/Ca record from 965 m water depth suggests that Glacial North Atlantic Intermediate Water formation was strong during the LGM, weakened during the deglaciation, and strengthened again during the Younger Dryas cold period. Comparison of Cd/Ca and δ13C data reveals apparent short-term changes in carbon isotopic air-sea signatures. Benthic foraminiferal Zn/Ca could be a sensitive paleoceanographic tracer because deep water masses have characteristic Zn concentrations that increase about ten-fold from the deep North Atlantic to the deep North Pacific. A "core top calibration" shows that Zn/Ca is controlled by bottom water dissolved Zn concentration and, like Cd/Ca and BalCa, by bottom water saturation state with respect to calcite Since Zn/Ca responds to a different range of saturation states than Cd/Ca, the two may be used together to evaluate changes in deep water carbonate ion (CO32- ) concentration. Zn/Ca and Cd/Ca ratios in the benthic foraminifer Cibicidoides wuellerstorfi exhibit large fluctuations over the past 100,000 years in a deep (3851 m) eastern equatorial Pacific sediment core. The data imply that bottom water CO32- concentrations were lowest during glacial Marine Isotope Stage 4 and highest during the last deglaciation. LGM CO32- concentrations appear to have been within a few μmol kg-1 of modern values. Deep North Atlantic Cd/Ca ratios imply much higher nutrient concentrations during the LGM. Although such data have usually been explained by a northward penetration of Southern Ocean Water (SOW), it has been suggested that they could result from increased preformed nutrient levels in the high-latitude North Atlantic or by increased aging of lower North Atlantic Deep Water (NADW). Glacial Zn/Ca data, however, require a substantially increased mixing with SOW and thus a reduction in NADW formation. Large changes in carbon isotopic air-sea exchange are invoked to reconcile benthic δ13C and trace metal data.<br>by Thomas Mathew Marchitto, Jr.<br>Ph.D.
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Cotton, Laura. "Paleogene larger benthic foraminifera of Tanzania and the Eocene-Oligocene Transition." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/42726/.
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Mass extinctions are important events for the evolution of life on Earth but often the mechanisms behind them are poorly understood. The Eocene - Oligocene Transition (EOT) had a profound and lasting influence on global climate and, though not one of the “big 5” mass extinction events, widespread extinctions in many fossil groups have been recognised. Larger benthic foraminifera (LBF), one of the most conspicuous and widespread fossil groups during the Eocene, are known to have experienced a rapid global overturning during the EOT, including the extinction of long-ranging families such as the Discocyclinidae, Orbitoclypeidae, Pellatispiridae and a number of species in the Nummulitidae. However, detailed records through the transition are rare, and few complete sections are known; the timing and causes of extinctions therefore remain uncertain. Extensive field samples from the southern Tanzanian coastal region along with Tanzania Drilling Project (TDP) samples are used to give an overview of Eocene to Miocene LBF and to produce high resolution stratigraphic records of LBF events across the EOT. Two further important EOT sites, Fuente Caldera, Spain and Melinau Gorge, Sarawak, both with unresolved questions relating to LBF at the EOT were studied for comparison. The field samples combined with the TDP data cover an area of approximately 200 km from Kilwa to the Mozambique border. Initial comparisons with Tethyan and Indo-Pacific faunas show perhaps an intermediate assemblage in the Eocene and some similarities with the Indo-Pacific in the Miocene. However in both epochs there are features distinctive of an East African or western Indo-Pacific fauna. Additionally, this work identifies many previously unreported localities and provides a solid basis for future work. Three of the TDP sites span the EOT and contain abundant LBF. Extensive calcareous micro-, nannofossil and stable isotope studies of these cores allow the LBF stratigraphy to be tied to global stratigraphy. These records show that the LBF extinction event occurs close to the Eocene/Oligocene boundary (EOB), as defined by the extinction of the planktonic foraminiferal Family Hantkeninidae, rather than at the prominent oxygen isotope excursion in the early Oligocene that signifies maximum ice growth and global sea-level fall. New bulk isotope data from the Melinau Limestone of Sarawak further support this conclusion. In Fuente Caldera, where the extinction level was previously reported to be within the Oligocene, extensive reworking means that an EOB extinction is also likely at this site. This correlation raises new questions about the cause of the extinctions and has important implications for global larger benthic foraminiferal stratigraphy.
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Bergh, Eugene. "Neogene to quaternary foraminifera from the western margin of southern Africa." Doctoral thesis, Faculty of Science, 2019. http://hdl.handle.net/11427/30436.
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The western margin of southern Africa underwent major palaeoceanographic changes since the initiation of the Benguela Upwelling System during the Neogene. Microfossils in marine sediments provide key proxies in our understanding of how the margin evolved. Fossil shells (tests) of foraminifera (singlecelled protists) from twenty cores from the Namibian shelf (199 to 309 m water depth) and three cores from the western slope (874 to 3631 m water depth) of South Africa were studied to determine the middle Miocene to Quaternary stratigraphy, palaeoenvironment and palaeoceanography of the western margin of southern Africa. Cores from the Namibian shelf recovered middle Miocene calcareous mud in erosional contact with overlying Pliocene to Pleistocene phosphatic sediments. Strontium isotope stratigraphy and planktic foraminifera biostratigraphy provide age control of the Namibian shelf sediments. The planktic indicator species Globoquadrina dehsicens and Globigerinoides bisphericus support strontium isotope stratigraphy results for the olive-green mud unit of the northern Namibian shelf indicating an age of 16 to 14 Ma, and the overlying Plio-Pleistocene age of the phosphorite-rich unit supported by planktic indicator species Globorotalia truncatulinoides and Globorotalia (Globoconella) inflata. Middle Miocene foraminifera reflect a warmer, oligotrophic, subtropical, deeper environmental setting in contrast to the shallower depositional environment, cooler conditions and a eutrophic bottom water setting indicated by Pleistocene foraminifera in the phosphatic units. The palaeoenvironment on the Namibian shelf was progressively shoaling during the Pleistocene as sea level amplitudes increased. An Uvigerina spp.- dominated association occurs in deeper shelf deposits dated to the early Pleistocene and the Ammonia beccarii association occurs in shallower shelf deposits of the late Pleistocene to Holocene. The planktic and benthic foraminiferal stable oxygen isotope records, colour reflectance (L*) and non-carbonate mineral counts provide age control on cores from the western slope of South Africa, whose records extend to just beyond Glacial Termination (GT) II. Sediment and benthic foraminiferal accumulation rates were higher during interglacial periods and lower during glacial periods. The major planktic species in the slope cores include Globorotalia (Globoconella) inflata, Globigerina bulloides and Neogloboquadrina incompta. Principal component analysis (PCA) reveals that the major factors influencing planktic foraminiferal abundances are upwelling intensity, the penetration of colder waters during glacial periods and the inflow of subtropical waters from the South Indian Ocean during interglacial periods. The major benthic species in the slope cores include Uvigerina peregrina, Uvigerina hispidocostata and Cibicidoides wuellerstorfi indicating the delivery of organic matter and oxygen availability to have the largest influence on the benthic foraminiferal faunal composition. Uvigerina spp. on the slope show increased relative abundances during periods of lower oxygen conditions. Bottom water masses identified by Nd (neodymium isotopic compositions) values recorded by foraminifera, along with the stable carbon isotope composition and abundance of the benthic foraminifer C. wuellerstorfi indicate shifts from Southern Component Water to North Atlantic Deep Water during GT II and I. Variation in Nd values in an upper slope core (874 m water depth) indicate Antarctic Intermediate Water (AAIW) influence was stronger during glacial periods compared to interglacial periods.
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Ozarko, Diana (Diana Lee) 1968 Carleton University Dissertation Earth Sciences. "Marsh foraminifera from Nanaimo, British Columbia: infaunal habitat and taphonomic implications." Ottawa.:, 1995.
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Eberwein, Astrid. "Holocene and Last Glacial Maximum (paleo-)productivity off Morroco : evidence from benthic foraminifera and stable carbon isotopes = (Paläo-)produktivität im Holozän und Letzten Glazialen Maximum vor Marokko erschlossen aus benthischen Foraminiferen und stabilen Kohlenstoffisotopen /." Bremerhaven : Alfred-Wegener-Institut für Polar- und Meeresforschung, 2007. http://www.loc.gov/catdir/toc/fy0712/2007425451.html.
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