Download or read book Assessing the Viability of Using Foraminifera from Mersey Estuary Saltmarsh Sediments to Reconstruct Former Sea Level written by Hayley Mills and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The viability of using a foraminifera-based transfer function method to reconstruct the local relative sea-level for the Mersey Estuary was assessed in this study, which has not been previously investigated in the UK in the context of application in a strongly macrotidal setting. A total of 105 surface samples were collected across two saltmarshes. Foraminiferal analysis was carried out, along with several environmental variables (organic matter content, salinity, pH, and grain size) to establish the species distribution of foraminifera and their relationship with elevation. Two main zonations were found: a high-to-middle marsh zone occupied by Haplophragmoides spp., J. macrescens and M. fusca; and a low marsh zone composed of increasing numbers of calcareous species including Elphidium spp.; and Haynesina spp. Foraminiferal distributions along each transect were found to be controlled predominantly by elevation and distance from tidal influence, whilst combined datasets reflected intra- and inter-site variability in the assemblages. Elevation was still found to have an important control over the distributions, with a strong relationship between the species zonations and elevation (r2 = 0.8). Therefore, the dataset (82 samples) formed a local training set in which a transfer function for the relationship between foraminifera species and elevation was developed. WAPLS was used as it produced the highest predictive ability (r2 jack = 0.85) and lowest prediction errors (RMSEPjack = 0.11 m). Regional and combined (local plus regional) transfer functions were also developed but the local transfer function produced the most accurate and reliable reconstruction. Reconstructions were carried out for both saltmarshes with reference to a sediment chronology which was established using radionuclides and pollution indicators. The reconstructions demonstrated the vast difference in the saltmarsh development and record of sea level between the sites. Oglet Bay developed as a result of increased accommodation space arising from changing estuary morphology, resulting in rapid accretion (2.34 cm year-1) and was found to be strongly influenced by tidal channel migration. Decoy Marsh accreted at a slower pace (0.32 cm year-1) and was less affected by tidal or morphological changes. Both reconstructions were affected by decalcification resulting in the reconstructions dating back to 1978 at the most. The reconstructed rates of sea-level change were 1.8 cm year-1 for Oglet Bay and 1.1 cm year-1 for Decoy Marsh, both of which over-estimate the trend from the monthly instrumental record (1.04 cm year-1) over the same period. The study highlights the problems which may arise when conducting research in an inner estuary which is strongly macrotidal, including tidal range changes, tidal asymmetry, and decalcification, but also demonstrates that a relatively precise and reliable reconstruction is achievable.
Download or read book Quantifying Holocene Sea level Change Using Intertidal Foraminifera written by Benjamin P. Horton and published by . This book was released on 2006 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Salt-marsh foraminifera have been used to reconstruct Holocene sea-level changes from coastlines around the world. In this work, we compile the results of surface foraminiferal surveys from fifteen study sites located on the east, south and west coasts of Great Britain, and the west coast of Ireland. These data, which comprise 236 samples and 84 species, are used to summarize the contemporary distributions of intertidal foraminifera around the British Isles, and to examine the environmental controls governing them.
Download or read book Salt Marsh Foraminiferal Proxy Record of Late Holocene Sea level Rise South Island New Zealand written by Brigida Orioli Figueira and published by . This book was released on 2012 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative vertical zonation of salt marsh foraminifera for reconstructing former sea level an example from New Jersey USA written by A.C. Kemp and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Foraminifera written by Barun K. Sen Gupta and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: "This is now the definitive, authoritative text on applied foraminiferal micropaleontology and should be in the library of all practicing micropaleontologists." (William A. Berggren, Woods Hole Oceanographic Institution in Micropaleontology, 47:1 (2001)"During the last 20 years there has been an explosion of publications about foraminifera from an amazing variety of disciplines: basic cell biology, algal symbiosis, biomineralization, biogeography, ecology, pollution, chemical oceanography, geochemistry, paleoceanography, and geology. This book summarizes contributions by leading researchers in these diverse fields. It is not just another text on the biology of foraminifera. Rather, Barun Sen Gupta has accomplished his objective to "write an advanced text for university students that would also serve as a reference book for professionals"." (Howard J. Spero, University of California at Davis in Limnology and Oceanography, 45:8 (2000).
Download or read book Application of Intertidal Salt marsh Foraminifera to Reconstruct Late Holocene Sea level Change at Kariega Estuary South Africa written by Kate Leigh Strachan and published by . This book was released on 2013 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reconstructing Historical Sea level Trends for the Croatian Coast of the Adriatic Sea Using Salt marsh Foraminifera written by Timothy Shaw and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Marsh Foraminifera to Construct a Late Holocene Sea Level History of the Raritan Estuary New Jersey written by Steven B. Lomax and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Salt marsh Foraminifera and Their Potential for Sea level Studies in the North Sea Region written by Katharina Müller-Navarra and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Modern Intertidal Zonation of Benthic Foraminifera as a Proxy for Estimating Former Sea level written by Mike Millar and published by . This book was released on 2004 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Modern Distribution of Foraminifera to Reconstruct Environmental Change Offshore Galveston Bay Texas written by Solveig H. Schilling and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sand is an important resource for coastal engineering. In Texas, many offshore sand deposits are found buried in Holocene fluvial sediments or estuarine environments like tidal channels or bayhead, flood, and ebb tide deltas. Exploring for these resources requires a comprehensive understanding of the depositional system in which they are buried. The distribution of benthic foraminifera can be used to reconstruct the paleoenvironment of sand-bearing Holocene estuary deposits. The Gulf of Mexico foraminifera have long been tied to specific environments, and facies in which one genera of benthic foraminifera is most abundant (i.e., the predominance facies) represent a promising technique to reconstruct paleoenvironment in Holocene cores. Although predominance facies have been well documented in Galveston Bay, to date, there are no equivalent records directly offshore for comparison, leaving the inner shelf assemblage unconstrained. Additionally, no direct comparisons have been made between ancient estuary assemblages and the modern living assemblages in Galveston Bay. To address this knowledge gap, this project examines the environmental evolution of the Trinity River estuary using benthic foraminifera and core data. The foraminifera trends offshore Galveston Bay show a greater diversity compared to estuary samples, which is likely driven by increased salinity on the inner shelf compared to Galveston Bay. The increased diversity of inner shelf assemblages compared to those of the bay can be used for recognizing offshore assemblages as distinct from estuarine samples in core data. Additionally, the comparison of living and Holocene estuary populations shows ancient samples with much higher dominance of Elphidium than is observed in the modern bay. This non-analogue population suggests environmental conditions (likely salinity) in the Holocene Trinity River estuary varied significantly from modern conditions implying a recent environmental change in the bay
Download or read book FORAMINIFERAL COMMUNITY DYNAMICS OF THE CHESAPEAKE GROUP CALVERT CLIFFS MARYLAND USA written by Seth Sutton and published by . This book was released on 2020 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-term impact of climate and sea-level change on marine communities can be documented using the fossil record of well-studied, and widely distributed organisms such as benthic foraminifera. The Calvert and Choptank formations of the Calvert Cliffs, MD were deposited during the Middle Miocene Climatic Optimum (MMCO) when global temperatures were ~3-6[degrees]C higher than present and the subsequent Middle Miocene Climatic Transition (MMCT) when global temperature dropped ~6 [degrees]C from peak temperatures of the MMCO. These strata also record five sea-level cycles separated by regionally continuous disconformities during these climate events. Previous studies on the benthic foraminifera of the Calvert Cliffs have been mostly taxonomic in scope. This study investigates the response of benthic foraminiferal communities in shelf sediments of the Calvert and Choptank formations from the Calvert Cliffs, Maryland.to the MMCO, the MMCT, and sea-level cycles. To accomplish these objectives, 21 laterally equivalent samples in each of three vertical, composite transects were collected from beds 4-18 of the Calvert Cliffs, MD for foraminiferal and grain-size analyses. Stratigraphic ranges of the foraminifera in the Calvert Cliffs dataset and relative abundance of all species were documented over the ~4-million-year period represented by the sampling scheme. The majority of abundant species occurred, with little change in relative abundance, over several sea-level cycles. Many rare species, however, occurred intermittently, indicating that these species were either present but not recorded due to their rareness or that these species had populations (a species pool) outside of the study area; that they migrated to and from over time. Cluster analysis of foraminiferal relative abundance data defined two groups, one composed of beds from the MMCO, characterized by assemblages of low energy, inner to mid-shelf environments and the other composed of samples vertically bracketing the first group, from the beginning of the MMCO and from the MMCT, characterizing higher energy, inner shelf environments. The diversity of each group and the taxa present were similar and the two groups and subgroups within them, the latter generally restricted to particular beds, were distinguished based on variations of the relative abundance and rank order of dominant species. Sediment grain-size data were used in conjunction with foraminiferal data to interpret the paleoenvironments of the strata. In summary, the data indicate warmer, deeper mid-shelf environments during the MMCO compared to cooler, shallower, inner shelf environments during the MMCT. The pattern of species distributions over five sea-level cycles indicates the need for a species pool from which species are recruited during transgressions.
Download or read book Sea Suraface Temperature Reconstruction Based on Planktonic Foraminifera of Surface Sediments and Sediment Cores Off Iberia Supplementary Data To Salgueiro Emilia Voelker Antje HL Abrantes Fatima F Meggers Helge Pflaumann Uwe Loncaric Neven Gonz lez lvarez Raquel Oliveira Paulo Bartels Jonsdottir Helga B Moreno Joao Wefer Gerold 2008 Planktonic Foraminifera from Modern Sediments Reflect Upwelling Patterns Off Iberia Insights from a Regional Transfer Function Marine Micropaleontology 66 3 4 135 164 written by Emilia Salgueiro and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative and qualitative analyses of planktonic foraminiferal assemblages from 134 core-top sediment samples collected along the western Iberian margin were used to assess the latitudinal and longitudinal changes in surface water conditions and to calibrate a Sea Surface Temperature (SST) transfer function for this seasonal coastal upwelling region. Q-mode factor analysis performed on relative abundances yielded three factors that explain 96% of the total variance: factor 1 (50%) is exclusively defined by Globigerina bulloides, the most abundant and widespread species, and reflects the modern seasonal (May to September) coastal upwelling areas; factor 2 (32%) is dominated by Neogloboquadrina pachyderma (dextral) and Globorotalia inflata and seems to be associated with the Portugal Current, the descending branch of the North Atlantic Drift; factor 3 (14%) is defined by the tropical-sub-tropical species Globigerinoides ruber (white), Globigerinoides trilobus trilobus, and G. inflata and mirrors the influence of the winter-time eastern branch of the Azores Current. In conjunction with satellite-derived SST for summer and winter seasons integrated over an 18?year period the regional foraminiferal data set is used to calibrate a SST transfer function using Imbrie & Kipp, MAT and SIMMAX(ndw) techniques. Similar predicted errors (RMSEP), correlation coefficients, and residuals' deviation from SST estimated for both techniques were observed for both seasons. All techniques appear to underestimate SST off the southern Iberia margin, an area mainly occupied by warm waters where upwelling occurs only occasionally, and overestimate SST on the northern part of the west coast of the Iberia margin, where cold waters are present nearly all year round. The comparison of these regional calibrations with former Atlantic and North Atlantic calibrations for two cores, one of which is influenced by upwelling, reveals that the regional one attests more robust paleo-SSTs than for the other approaches.
Download or read book Using Foraminiferal Assemblages to Reconstruct Climate Change in the Northwestern Weddell Sea Antarctic Peninsula written by Anastasia Kyrmanidou and published by . This book was released on 2018 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this dissertation was to investigate the benthic foraminiferal assemblage dynamics of the northwestern part of the Weddell Sea and to utilize them as oceanographic proxies. Spatial and temporal patterns of foraminiferal assemblages are correlated with other proxies in order to reconstruct and better understand Antarctic Peninsula (AP) paleoenvironmental changes, particularly those pertaining to bottom-water circulation, glacial fluctuations, and biological productivity on the eastern margin of the AP (EAP). This area in the northeast Antarctic Peninsula has experienced significant environmental change evidenced by the collapse of both Larsen-A and Larsen -B ice shelves, involving various preconditioned and sequential transitions in cryosphere and ecosystem dynamics. The first project (Chapter 3) presents an expanded foraminiferal and diatom record from Perseverance Drift, northeastern AP. Using benthic foraminifera and diatoms as paleoenvironmental proxies for paleoproductivity and sea ice conditions in the area, a record extending back to 3400 yr BP, constrained via radiocarbon dating of biogenic calcite was produced. The variability of the recor was compared with existing paleoenvironmental marine records of the AP, which recognize Holocene hypsithermal and cooling events, such as the Mid-Holocene Climatic Optimum and the Neoglacial period. Overall, Holocene climatic variability is complex, with warm and cool phasing occurring at different rates and at different times across the AP (Bentley et al., 2009). Based on the foraminiferal and diatom record of Perseverance Drift, this study recognizes two main intervals of climatic variability. The basal unit of the composite core, characterized by high abundances of Globocassidulina spp. Foraminiferal Assemblage (FA), indicates incursions of Weddell Sea Transitional Water over the drift site. This interval implies a period of 'freshening' of the water column, coinciding with an open-marine or seasonally open-marine environment during the middle-to-late Holocene Climatic Optimum. The upper unit of the composite core displays characteristics of slightly colder climatic conditions as indicated by the absence of calcareous foraminifera Globocassiulina spp. FA and the pronounced presence of agglutinated FAs that are indicative of the presence of heavy sea ice. Therefore, this interval is interpreted to represent the onset of Neoglaciation at the northeastern tip of the AP. The main objective of the second project (Chapter 4) was to understand modern trends in the foraminiferal-environmental relationship in order to be able to accurately interpret the environmental conditions represented in paleo-records from the eastern part of the AP (EAP), and more specifically the formerly ice shelf-covered Larsen A embayment. This project compared already published data reporting on modern foraminiferal assemblage distributions from the Larsen A embayment (collected in March 2000) with new data reporting on modern foraminiferal assemblage distributions (collected in March 2012) from approximately the same sampling locations that follow an inshore to offshore transect designed to serve as a spatial approximation for temporal differences in ice shelf coverage over the past several decades. Additionally, down-core (2012) samples were analyzed and compared with the modern datasets in an attempt to obtain longer-term information regarding the foraminiferal communities' status pre-collapse. The main difference within the span of 12 years separating the sampling efforts is the removal of the calcareous component from the foraminiferal dataset in stations from the inner part of the embayment, situated closer to the ice shelf edge. The down-core foraminiferal data, seem to be following the same pattern as observed in the modern datasets, therefore, providing proof of the concept that distance from the ice shelf edge, in combination with the effects of taphonomical dissolution and locally increased food availability, is a factor that can structure the benthic foraminiferal community composition in environments characterized by ice shelf collapse, such as the Larsen A embayment. The third project (Chapter 5) provides an analysis of foraminiferal assemblages collected from sediment core GC16B near the northern margin of Larsen C ice shelf. Foraminiferal analysis of samples collected from this core revealed a diverse assemblage of calcareous benthic foraminiferal taxa in the upper 20 cm of the core, with very low contribution from agglutinated forms. Owing to the very low absolute diatom abundance values that characterize the core, the high abundance of planktonic foraminiferal taxa relative to benthic foraminiferal taxa, and the dominance patterns of the benthic foraminiferal taxa, different hypothesis pertaining to the source of productivity in this sub-ice shelf environment have been employed involving the transport of advected food supply from the open Weddell Sea and the response of the foraminiferal fauna to less productive (than labile) organic matter as their food source.
Download or read book Coastal Signals of Environmental Changes Foraminifera as Benthic Monitors written by Inda Brinkmann and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate changes, tightly linked to anthropogenic activities, are significantly altering environments and ecosystems globally, such as by increasing marine and coastal deoxygenation or occurrences of extreme weather events. The significance of paleoenvironmental and -climate reconstructions, as well as monitoring of current conditions, for unravelling baseline natural variation, today's changes and potential future impacts, has been recognised by the Intergovernmental Panel on Climate Change (IPCC) reports. However, to access past records of physical and chemical environmental variables, and comprehensively assess ecosystem reactions, reliable and sensitive proxies are critical. This thesis' focus lies on benthic foraminifera--unicellular protists with mineralised or organic test, abundantly inhabiting ocean and coastal sediments--and their calibration as indicator for a variety of environmental conditions in field-sampling approaches. The research projects follow two general strategic tracks: (I) a biogeochemical assessment of trace-elemental ratios in foraminiferal calcium-carbonate tests using high-resolution, micro-analytical techniques; (II) a molecular approach investigating foraminiferal environmental DNA derived from coastal sediments. Papers I and II concern the calibration of the benthic foraminiferal Mn/Ca proxy for marine oxygenation conditions in modern field studies. Trace-element concentrations and distributions were measured by plasma-, laser- and synchrotron-based analyses in a high-resolution, individual-foraminifera approach, and interpreted in the context of ambient physical and chemical conditions of the water column, pore-waters and sediments (including oxygen and manganese concentrations). Investigating two coastal systems with almost permanently severely oxygen-deficient bottom-waters (Santa Barbara Basin, Paper I), and undergoing a seasonal oxygenation cycle across the low- to well-oxygenated range (Gullmar Fjord, Paper II), respectively, demonstrated the utility of the Mn/Ca proxy for indicating low-oxygen conditions specifically. Continued calibration efforts under consideration of ambient oxygenation and redox regimes may open further possibilities of quantitative oxygen reconstructions. Paper III explores the use of coastal, benthic Ba/Ca records as indicator of riverine runoff and drought on land across the years 2018 and 2019, characterised by severe heat and drought, and warm and wet conditions, respectively. Benthic Ba/Ca correlated significantly with the hydroclimate conditions, as inferred from extensive meteorological and hydrological data sets of the region, highlighting qualitative proxy potential for paleo-drought reconstructions. Based on ambient sediment and pore-water geochemistry, we discuss mediation of water-column transport and pore-water Ba cycling by Fe and Mn oxides. All three investigations of these geochemical proxies (Paper I-III) highlighted the significance of biological controls on foraminiferal TE/Ca, which are species-specific and, thus, should be a deciding factor in choosing proxy candidate species. In particular the influences of micro-habitat distribution and utilised metabolic pathways by foraminifera are discussed in detail. In Paper IV foraminiferal biodiversity and assemblage responses to natural and anthropogenic environmental trends in a fjord system (Swedish west coast) are documented in a metabarcoding approach. Environmental DNA successfully tracked biodiversity and community composition changes associated with contrasting ecosystems but showed damped sensitivity to environmental variability on sub-annual time-scales. Overlaps and discrepancies between molecular and traditional, observation-based assessment techniques, as well as future trajectories to resolve uncertainties are discussed. Overall, this thesis solidifies and expands the currently available proxy toolbox for reconstructions of both coastal low-oxygen, as well as terrestrial hydroclimate conditions. The findings contribute towards filling current knowledge gaps pertaining to biotic impacts on foraminifera-derived biogeochemical signals and methodological uncertainties in metabarcoding approaches and highlight the significance of implementing molecular techniques in conventional foraminiferal assemblage studies.
Download or read book Quaternary Foraminifera of the Caspian Black Sea Mediterranean Corridors Volume 1 written by Valentina Yanko and published by Springer. This book was released on 2023-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook in two volumes offers a heretofore unavailable compilation of detailed information on foraminifera of the Caspian-Black Sea-Mediterranean Corridors (“CORRIDORS”), including their taxonomy, ecology, and applications in the study of Quaternary stratigraphy, paleogeographic reconstruction, and environmental stress. This subject is significant in light of the ongoing debates regarding the Flood Hypotheses because foraminifera can provide more information about many of the disputed questions. Foraminifera are highly reliable paleoenvironmental indicators, ubiquitous in marine environments, and taxonomically diverse, which gives them the potential for a wide range of biological responses to varied environmental factors. Their tests are readily preserved and can record evidence of environmental change through time, thus providing historical baseline data even in the absence of background studies. This book presents taxonomic descriptions for about 500 species and subspecies from the Black Sea, Sea of Azov, Caspian Sea, Aral Sea, Sea of Marmara, and the Eastern Mediterranean. This catalogue is supplemented by ecological remarks, stratigraphic distributions, paleogeography, and environmental/paleoenvironmental applications, including responses to environmental stress, e.g., river discharge, pollution by different contaminants, etc. The book will be useful to specialists in Quaternary history of the “CORRIDORS” as well as those in environmental monitoring and risk assessment. This handbook offers detailed taxonomic descriptions of foraminifera from the Black Sea, Caspian Sea, Sea of Azov, Aral Sea (in Volume 1) and Eastern Mediterranean and Sea of Marmara (in Volume 2).
Download or read book Distributions and Population Dynamics of Marsh Estuarine Foraminifera with Applications to Relocating Holocene Sea Level written by David B. Scott and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
