Showing papers on "Foraminifera published in 1985"
TL;DR: In this article, an analysis of living (stained) benthic foraminifera within the upper 15 cm of deep-sea sediments, which reveals species-specific microhabitat preferences, with distinct morphological features found with epifaunal and infaunal species.
Abstract: Benthic foraminifera are protozoans found throughout the deep-sea environment, secreting a test of calcium carbonate or constructing a test of cemented sediment particles (agglutinated or arenaceous foraminifera). In typical deep-sea sediments, the organic cement of agglutinated taxa degrades upon burial in the sediment and, consequently, few specimens survive in the fossil record. In contrast, calcareous species are well preserved in most oceanic sediments, except at abyssal depths where most carbonate sediment is dissolved because of high levels of carbonate under-saturation of the bottom waters. Although benthic foraminifera have been widely used in studies of Cenozoic palaeoceanography, little is known about the ecology of deep-sea species. I present here an analysis of living (stained) benthic foraminifera within the upper 15 cm of deep-sea sediments, which reveals species-specific microhabitat preferences, with distinct morphological features found with epifaunal and infaunal species. The existence of infaunal habitats suggests that the distribution of certain foraminifera is not directly controlled by overlying bottom-water conditions, but by physicochemical conditions within the sediments. The microhabitat preferences may also explain interspecific carbon isotope differences, as existing data show that infaunal foraminifera generally have lower δ13C isotope values than epifaunal species.
792 citations
TL;DR: In this paper, the authors compared the living and dead foraminiferal assemblages from 45 stations on the Norwegian continental margin and in the Norway Basin, and found that the living assemblage is characterized byCassidulina teretis andPullenia bulloides.
284 citations
184 citations
TL;DR: This article found microtektite-like spherules have been found in almost every core or outcrop with an iridium anomaly, forming a worldwide strewnfield, which is an excellent indicator of the K/T boundary level.
163 citations
140 citations
TL;DR: In this paper, the response of deep ocean circulation to major climatic events of the past 135,000 years is inferred using carbon-13 analyses of benthic foraminifera from the major ocean basins.
Abstract: The response of deep ocean circulation to major climatic events of the past 135,000 years is inferred using carbon-13 analyses of benthic foraminifera from the major ocean basins. The results demonstrate that the circulation of the world ocean deep water is very sensitive to climate and that it changes drastically during climatic transitions.
140 citations
125 citations
TL;DR: It was concluded that shell fluxes through the water column may be calculated with reasonable accuracy using a modified version of the Bishop et al. (1977) settling model and empty shell size distribution data from pump and plankton tow collections.
123 citations
TL;DR: In this article, continuous swamp and lacustrine sequences from the northern edge of the Great Western Erg are dated at 9,300-3,000 yr BP, and the stable isotope composition of carbonates indicates that evaporation of groundwater supplies is responsible for these fluctuations in salt contents.
Abstract: Continuous swamp and lacustrine sequences from the northern edge of the Great Western Erg are dated at 9,300–3,000 yr BP. Diatoms, ostracods, molluscs and foraminifera show great changes in salinity, ranging from freshwater to marine-like environments. The stable isotope composition of carbonates indicates that the evaporation of groundwater supplies is responsible for these fluctuations in salt contents. Until now, evidence for the occurrence of a wet climatic phase of early and middle holocene age in the north-north-west Sahara was based on a restricted number of 14C dates from scattered lacustrine deposits and paleosols1–8. The present study complements this knowledge and highlights the importance of local hydrological factors in interpreting palaeolimnological changes.
120 citations
01 Jan 1985
TL;DR: In this paper, the authors describe the evolution of the world ocean during the Miocene Epoch, that interval of time between about 24 and 5 Ma, that is the time when major polar ice sheets became a permanent feature of the earths surface; it was a transition interval between the Oligocene ocean and the more familiar late Cenozoic ocean.
Abstract: This volume is about the paleoceanography and paleobiogeography of the world ocean during the Miocene Epoch, that interval of time between about 24 and 5 Ma. The sedimentary sequences upon which these studies were based resulted from the highly successful Deep Sea Drilling Project (DSPD). Since 1968, deep-sea drilled sections have been obtained from all ocean basins except the Arctic using D. V. Glomar Challenger. These sections represent an enormously important resource for earth science investigations. All but one of the 14 contributions in this volume are products of research within the Cenozoic Paleoceanography project (CENOP), a multi-institutional project established to generate paleoceanographic reconstructions of the Miocene ocean using stable isotopes and quantitative micropaleontological data. CENOP investigations have generated data related to a wide range of parameters and processes of the Miocene ocean including paleogeography, stratigraphy, circulation, water-mass distributions, temperature, variability, vertical water-mass structure, biogeography, and biotic evolution. Ocean evolution of the Miocene was chosen by CENOP investigators because it was an interval of time of major ice accumulation on Antarctica, with related global paleoclimatic and paleoceanography changes. The Miocene was the interval of time when major polar ice sheets became a permanent feature of the earths surface; it was a transition interval between the still unfamiliar Oligocene ocean and the more familiar late Cenozoic ocean. The base of the Miocene is marked by the beginning of major evolutionary radiations of oceanic microfossils, especially planktonic foraminifera, which lead to distinctive Neogene lineages; the end of the Miocene is marked by the terminal Miocene Event represented by an extraordinary number of global paleoenvironmental changes such as global cooling and the Mediterranean salinity crisis. A number of important changes occurred in the ocean during the Miocene that strongly affected oceanic biogeographic patterns and biotic evolution. Among the changes was a major steepening of thermal gradients of surface waters as the circum-Antarctic Current continued to expand and intensify. Part of this increase in pole to equator surface-water temperature gradient resulted from cooling in high latitudes, but also to warming of low-latitude surface waters.
95 citations
TL;DR: In this paper, the average δNd(0) value from this study agrees well with previous estimates of the average Nd isotopic composition of the Atlantic based on analyses of ferromanganese deposits and seawater samples.
TL;DR: In this article, 13 C/12 C ratios of Miocene benthic foraminifera from 22 Pacific Ocean sites vary with time but are similar at almost all sites in any restricted interval, reflecting the deposition of greater amounts of organic matter on the continental shelves during transgressions.
Abstract: 13 C/ 12 C ratios of Miocene benthic foraminifera from 22 Pacific Ocean sites vary with time but are similar at almost all sites in any restricted interval. δ 13 C values are correlated with sea levels inferred from onlap/offlap curves, reflecting the deposition of greater amounts of organic matter on the continental shelves during transgressions. Differences in δ 13 C between sites are correlated with local differences in biological productivity in the overlying surface waters. 13 C/ 12 C values of benthic foraminifera show promise as indicators of marine paleoproductivity.
TL;DR: Sedimentological study of 20 piston cores from the northwestern Labrador Sea shows that thin bedded distal turbidites are important constituents of the Quaternary strata on the continental slope and rise as mentioned in this paper.
Book•
01 Jan 1985
TL;DR: In this paper, a coarse fraction analysis of five sediment cores from the Eastern Walvis Ridge has been carried out by means of a quantitative coarse-fraction analysis (>40 μm).
Book•
20 May 1985
TL;DR: A review and an update of the Eocene-Oligocene Marine Chronostratigraphy can be found in this paper, along with an overview of the evolution of the Pacific Coast Eichters of the United States.
Abstract: Part I: The Pacific Rim Pacific Coast Eocene-Oligocene Marine Chronostratigraphy: A Review and an Update, by Donald R. Prothero Turnovers in Marine Gastropod Faunas During the Eocene-Oligocene Transition, West Coast of the United States, by Richard L. Squires Biotic Response to the Eocene-Oligocene Transition: Gastropod Assemblages in the High-Latitude North Pacific, by Anton E. Oleinik and Louie Marincovich Jr. Changes in Shallow-Marine Faunas from the Northeastern Pacific Margin Across the Eocene/Oligocene Boundary, by Elizabeth A. Nesbitt Evidence for Abrupt Eocene-Oligocene Molluscun Faunal Change in the Pacific Northwest, by Carole S. Hickman An Overview of Eocene-Oligocene Echinoderm Faunas of the Pacific Northwest, by Casey Burns and Rich Mooi Upper Eocene Greenhouse Deposits in Southern Australia: Paleoclimatology and Paleoceanography, by Paul R. Gammon, Yvonne Bone, Jonathan D.A. Clarke, and Noel P. James The Meiji Drift Body and Late Paleogene-Neogene Paleoceanography of the North Pacific-Bering Sea Region, by David W. Scholl, Andrew J. Stevenson, Marlene A. Noble, and David K. Rea Cetacean Evolution and Eocene-Oligocene Oceans Revisited, by R. Ewan Fordyce Terrestrial Eocene-Oligocene Vegetation and Climate in the Pacific Northewest, by Jeffrey A. Myers Part II: The Atlantic, Gulf, and Caribbean Sequence Stratigraphy of the Eocene/Oligocene Boundary Interval: Southeastern Mississippi, by Ronald J. Echols, John M. Armentrout, Stephan A. Root, Larry B. Fearn, James C. Late Middle Eocene Glacioeustasy: Stable Isotopes and Foraminifera from the Gulf Coastal Plain, by John V. Hurley and Richard H. Fluegeman Paleogene Temperature History of the U.S. Gulf Coastal Plain Inferred from -- of Fossil Otoliths, by Linda C. Ivany, Kyger C. Lohmann, and William P. Patterson The Palynological Record of Late Eocene Climate Change, Northwest Gulf o Mexico, by Thomas E. Yancey, William C. Elsik, and Recep H. Sancay Palynological Patterns in Uppermost Eocene to Lower Oligocene Sedimentary Rocks in the U.S. Gulf Coast, by Francisca E. Oboh-Ikuenobe and Carlos A. Jaramillo Late Eocene-Early Oligocene Benthic Foraminifera in the Gulf Coastal Plain: Regional vs. Global Influences, by Richard H. Fluegeman Upper Paleogene larger Foraminiferal Succession on a Tropical Carbonate Bank, Nicaragua Rise, Caribbean Region, by Edward Robinson Molluscan Faunas Across the Eocene/Oligocene Boundary in the North American Gulf Coastal Plain, with Comparisons to Those of the Eocene and Oligocene of France, by David T. Dockery III and Pierre Lozouet Biotic Patterns in Eocene-Oligocene Echinoids of the Southeastern United States, by Burchard D. Carter The Eocene-Oligocene Transition in Marine Vertabrates of the Gulf Coastal Plain, by Earl M. Manning A Brief Account of the Evolution of the Caribbean Seaway: Jurassic to Present, by Manuel A. Iturralde Vinent The Eocene-Oligocene Transition in the Equatorial Atlantic (ODP Site 925): Paleoproductivity Increase and Positive -- Excursion, by Liselotte Diester-Haass and Jim Zachos Part III: The North Sea and Tethys The Eocene/Oligocene Boundary in the North Sea Area: A Sequence Stratigraphic Approach, by Noel Vandenberghe, Henk Brinkhuis, and Etinne Steurbaut Deep-Water Benthic Foraminiferal Events from the Massignano Eocene/Oligocene Boundary Stratotype, Central Italy, by Rodolfo Coccioni and Simone Galeotti Stratigraphy and Benthic Foraminiferal Events Across the Middle - Late Eocene Transition in Western Negev, Israel, by Roberto Barbieri, Chaim Benjamini, Simonetta Monechi, and Viviana Reale The Development of Facies Patterns of Middle Eocene to Lower Oligocene Circum-Alpine, Shallow-Water Carbonate Environments, by James H. Nebelsick, Michael Rasser, and Davide Bassi Part IV: Causes and Consequences Late Eocene Impacts: Geologic Record, Correlation, and Paleoenvironmental Consequences, by C. Wylie Poag, Edward Mankinen, and Richard D. Norris Boundaries, Turnover, and the Causes of Evolutionary Change: A Perspective from the Cenozoic, by Warren D. Allmon The Marine Eocene-Oligocene Transition: A Synthesis, by Linda C. Ivany, A. Nesbitt, and Donald R. Prothero Contributors Index
TL;DR: In this article, the interglacial deposits at Tattershall castle and at Tatterhall Thorpe, Lincolnshire, are described, which are overlain by between 3 and 8 m of fluvial gravel and sand in which ice-wedge casts are preserved.
Abstract: Interglacial deposits exposed in gravel pits near Tattershall Castle and at Tattershall Thorpe, Lincolnshire, are described. These consist predominantly of detritus muds and silts which fill channels cut into the underlying Wragby Till. The interglacial deposits at both sites are overlain by between 3 and 8 m of fluvial gravel and sand in which ice-wedge casts are preserved. Radiocarbon dates from silt lenses within these gravels confirm a Middle Devensian age for this aggradation. The interglacial deposits from both sites are rich in fossils (pollen, plant macrofossils, Mollusca, Ostracoda) which are described in detail. They also contain some foraminifera and vertebrate fossils in Tattershall Castle pit. The molluscan faunas were unusually rich, with a combined total of 86 taxa recorded including many land snails, two of which (Cochlicopa nitens and Vitrea subrimata) have not previously been reported from the British Pleistocene. The fossil evidence from Tattershall Castle pit indicates that the interglacial sediments were deposited by a slow-flowing, well vegetated stream during substage IIb of the Ipswichian Interglacial. An early Ipswichian age is also suggested for the basal calcareous silts, which contain an open-country molluscan fauna, previously ascribed to the late Wolstonian. The correlation is strengthened by uranium-series disequilibrium dates suggesting an age between 75 and 115 ka B.P., a thermoluminescence date of 114 $\pm$ 16 ka B.P. and by amino acid racemization data from molluscan shells. The occurrence of brackish-water species of Mollusca, Ostracoda and foraminifera indicates mildly brackish conditions occurred during deposition between -1.8 and -0.2 m O.D. Several plants and molluscs occur that are no longer present in Britain and these provide some evidence that summer temperatures may have been slightly warmer than those of today. Winter temperatures also appear to have been mild. The banding polymorphism of the snails Cepaea spp., analysed here for the first time from a British interglacial site, might also give evidence of a warm climate. Evidence of interglacial conditions from Tattershall Thorpe comes from infills of two palaeochannels. The fossiliferous detritus muds in the channel studied in most detail (1979-1982) appear to result from deposition in nearly stagnant water under fully temperate conditions with regional mixed oak forest, during substage II of an interglacial. These deposits are at a higher elevation (5-6 m above O.D.) than those at Tattershall Castle and contain no evidence of brackish conditions. Silty clay from the second channel (studied mainly by other workers, in 1971) yielded pollen spectra referred to substage IV of the Ipswichian Interglacial, and a molluscan assemblage indicative of moving water in a river channel.
TL;DR: In this paper, the authors present the results of a study on the relationship between geology and geophysics, focusing on the geophysical properties of the Earth's magnetic field.
Abstract: •Present address: Department of Geological and Geophysical Science, Princeton University, Princeton, New Jersey 08540.
TL;DR: In this paper, the quantitative distributions of planktonic foraminifera and pteropods were analyzed in seven Red Sea cores and two deep-sea cores from the Gulf of Aden and off Sokotra Island.
TL;DR: In this article, an analysis of middle Eocene through Oligocene samples from the Gay's Cove, Bath Cliffs, and Codrington College sections (Oceanic Formation, Barbados) demonstrates the presence of two major benthic foraminiferal assemblages: Nuttallides truempyi (middle Eocene to earliest late Eocene) and Globocassidulina subglobosa-Cibicidoides ungerianus-Gyroidinoides (late Eocene-Oligocene).
Abstract: Examination of middle Eocene through Oligocene samples from the Gay's Cove, Bath Cliffs, and Codrington College sections (Oceanic Formation, Barbados) demonstrates the presence of two major benthic foraminiferal assemblages: Nuttallides truempyi (middle Eocene to earliest late Eocene) and Globocassidulina subglobosa-Cibicidoides ungerianus-Gyroidinoides (late Eocene through Oligocene). The latter may be subdivided into a C. ungerianus-G. subglobosa assemblage (late Eocene), a G. subglobosa assemblage (early Oligocene), and a C. ungerianus assemblage (late Oligocene). A dramatic decrease in abundance of Nuttallides truempyi marks the most important faunal abundance change in the studied interval. This change occurred in Barbados just above the middle/late Eocene boundary, correlating with a similar event that occurred throughout lower bathyal to abyssal locations in the Atlantic Ocean. Nuttallides truempyi and Abyssamina spp. disappeared at the end of the Eocene in Barbados. Otherwise, no major benthic foraminiferal changes (abundance, appearances or disappearances) occurred across the Eocene/Oligocene boundary here. Comparisons of benthic foraminifera from Barbados with distribution data obtained from "backtracked" Deep Sea Drilling Project (DSDP) sites suggest that the Oceanic Formation was deposited in the upper abyssal zone (2000-3000 m), probably in the lower portion of this zone (ca 2500-3000 m).
TL;DR: The LOREX cores include at least 12 sedimentary subunits differentiated by texture, color, and carbonate content as discussed by the authors, including silty and arenaceous lutites and are principally glacial-marine.
Abstract: Sediments of 16 short cores taken as part of the Lomonosov Ridge Experiment (LOREX) can be organized into the first Pleistocene stratigraphy for the North Polar region. This stratigraphy can be correlated with stratigraphic units described from the Alpha-Chukchi areas, ∼300 km distant. The LOREX cores include at least 12 sedimentary subunits differentiated by texture, color, and carbonate content. The units are silty and arenaceous lutites and are principally glacial-marine. Benthic and planktonic foraminifera, degree of bioturbation, and Fe-Mn micro-nodule abundance generally are positively correlated. Foraminifera in core B-8, from 3,956 m in the Makarov Basin, may have been affected by CCD fluctuations that did not affect fossils in core B-24, from 1,600 m on the crest of the Lomonosov Ridge. The 12 stratigraphic units were deposited during the late Pleistocene and represent the same major sedimentary events as those of stratigraphic units K, L, and M of the Amerasian Basin. This correlation is excellent evidence for the remarkable and widespread uniform depositional style of glacial-marine sediment. Times of major glacial ice transport reflect deglaciation events in the central Arctic Ocean. Surface currents during deglaciation transport glacial ice in a more or less uniform pattern over at least 50% of the Arctic Ocean. Even thin sedimentary units deposited during relatively long time intervals are correlated over >500,000 km 2 .
01 Jul 1985
TL;DR: Gaveshani et al. as discussed by the authors analyzed living planktonic foraminifera from three cruises of the eastern Arabian Sea (R.V. Gaveshani, November 1982, Osiris II-MD-10, July 1976; and Osiris III -MD-13, June 1977) were analyzed in the present study.
Abstract: Living planktonic foraminifera from three cruises of the eastern Arabian Sea (R.V. Gaveshani, November 1982; Osiris II-MD-10, July 1976; and Osiris III-MD-13, June 1977) were analyzed in the present study. Planktonic foraminifera of the eastern Arabian Sea are much more abundant at 0 to 10 than at 0 to 200 m, but species diversity is less. G. ruber and G. sacculifer are the most abundant species in the eastern Arabian Sea water column. G. aequilateralis, G. glutinata, P. obliquiloculata, G. menardii, G. tenelus, G. hexagona, and G. pachyderma dwell preferentially in deeper water. In the November cruise, three assemblages were found: a winter tropical assemblage (southern Arabian Sea), a winter tropical assemblage (middle Arabian Sea), and a winter tropical upwelling assemblage (northern Arabian Sea). Another tropical upwelling assemblage was encountered during the July cruise. The variation of living planktonic foraminifera in the eastern Arabian Sea appears to be governed more by upwelling events, which vary seasonally and spatially, than by seasonal seawater temperature and latitude variations.
TL;DR: In this article, evidence from terrestrial sections, ice cores, and marine cores are reviewed and used to develop a scenario for environmental change in the area of the extreme northwest North Atlantic during marine isotope stages 5 and 4.
TL;DR: In this paper, the authors compared living and dead foraminiferal assemblages in the North Sea and the continental shelf of the UK and found that the northern North Sea is very fertile and has high standing crop values.
Abstract: . The regions studied are all of mid continental shelf depth (70–145 m) and have bottom waters of normal marine salinity. The North Sea has lower bottom water temperatures than those to the west of Scotland. However, the major difference between the two regions is one of tidal and/or wave energy: the northern North Sea is a low energy environment of muddy sand deposition whereas the sampled part of the continental shelf west and north of Scotland is a moderate to high energy environment of medium to coarse biogenic carbonate sedimentation. The physical differences between the two main areas are reflected in the living and dead foraminiferal assemblages. The northern North Sea is a region of free-living species whereas the continental shelf west of Scotland has immobile and mobile attached species living on firm substrates. The northern North Sea is very fertile and has high standing crop values. The dead assemblages are small in size and very abundant. To the west of Scotland the sea is less fertile, standing crop values are low, the dead assemblages are moderate to large in size and reasonably abundant due to the slow rate of dilution by sediment.
Journal Article•
TL;DR: Foraminiferal assemblages in thin sections of lower Miocene cores from the Matinloc 2 and Libro 1 wells off the northwest coast of Palawan, Philippines, revealed similar biofacies in the two wells as mentioned in this paper.
Abstract: Study of the calcareous foraminiferal assemblages in thin sections of lower Miocene cores from the Matinloc 2 and Libro 1 wells off the northwest coast of Palawan, Philippines, revealed similar biofacies in the two wells. Multivariate and morphometric analysis of the fora- miniferal data distinguished three assemblages. These three assemblages helped to define four distinct facies that are found in both wells: 1) small foraminiferal grainstone-packstones charac- terized by small rotaliines and miliolines, 2) coral boundstones with foraminiferal-algal packstones in which a small rotaliine-milioline assemblage is represented along with some larger rotaliine foraminifera, 3) algal-larger foraminiferal packstones characterized by Amphistegina and miogyp- sinids, and 4) larger foraminiferal wackestones in which large, flat, oriented lepidocyclinids and Cycloclypeus dominate in a micrite matrix that bears planktonic foraminifera. These four facies were interpreted to represent, respectively: 1) lagoonal sediments, 2) coral-rubble reef flat or reef margin, 3) algal-stabilized reef flat, and 4) drowned reef or slope sediments. The depositional history of the 104 m of Matinloc 2 core is interpreted as follows: lagoonal infill topped by shallow algal-stabilized reef flat is indicated in the lower 44 m of core. A slight increase in energy on the reef flat allowed for temporary colonization by coral before replacement by vegetated reef flat. Finally, a major transgressional sequence of reef flat to reef to drowned reef is evident in the upper 41 m of the core. The drowned-reef limestones are overlain by shales. The Libro 1 core, though incomplete, shows similar conditions of shallow lagoon and reef flat in the lower portion and progressive drowning of the reef in the upper portion.
TL;DR: In this article, the authors examined the distribution of microfossils in ten turbidites from the western levee of the Monterey Fan to determine how turbidite micro-fossil assemblages differ from those of hemipelagic intervals, and if turbiditic muds can be distinguished from hemipelagales based on fossil content.
Abstract: Recognition of the Pleistocene/Holocene boundary and biohorizons on the continental margin of California is complicated by turbidite deposition. The coiling ratio of Neogloboquadrina pachyderma (Ehrenberg), the relative frequencies of subarctic and transitional planktonic foraminifers, radiolarian number, and the radiolarian-foraminiferal ratio all show variability in upper Quaternary sections that appear related to downslope transport processes, in addition to the environment of surface waters and carbonate dissolution. We examined the distribution of microfossils in ten turbidites from the western levee of the Monterey Fan to determine 1) how turbidite microfossil assemblages differ from those of hemipelagic intervals, 2) if turbiditic muds can be distinguished from hemipelagic muds based on fossil content, and 3) if microfossils used to define biostratigraphic zones are significantly affected by turbiditic processes. Using cluster analysis, samples were successfully divided into hemipelagic and turbiditic groups based on the relationship among five of 16 variables (cluster A): sand content, the relative frequency of shallow-water benthonic Foraminifera, benthonic foraminiferal number, adjusted benthonic foraminiferal number, and the relative frequency of dextral Neogloboquadrina pachyderma (Ehrenberg). The variables jointly characterize a transitional assemblage transported from a bathyal or neritic source. Both Radiolaria and planktonic Foraminifera are used to mark biohorizons on the California continental margin. In this study, it was found that both fossil groups vary significantly in concentration and relative frequency between turbiditic and hemipelagic muds of the Monterey Fan, and microfossil assemblages are measurably different between tops and bases of turbidites. The coiling ratio of Neogloboquadrina pachyderma (Ehrenberg) varies the least and may be most resistant to bias by hydraulic sorting and differential carbonate preservation related to transport processes.
TL;DR: Foraminifera from 15 boreholes put down through Quaternary deposits in North Jutland have been examined as discussed by the authors, and the biostratigraphy of these borings allows a comparison with the biozones N1-N4 already established at Skaerumhede I.
Abstract: Foraminifera from 15 boreholes put down through Quaternary deposits in North Jutland have been examined. The biostratigraphy of these borings allows a comparison with the biozones N1-N4 already established at Skaerumhede I. The most well defined zone over the whole area is the Eemian zone N3, which contains boreal to boreal -lusitanian deep-water faunas. The lowermost boundary of this zone drops from 155 m below sea-level in the southwest of the area to about 205 m in the north, and its thickness normally ranges from 25 to 60 m. Variations in the depth and thickness of zone N3 may suggest that tectonic movements have been active in the area during the Late Quaternary. In the southern part of the region an arctic zone N4 was observed underlying the Eemian. Marine conditions must therefore have inundated the areas at the end of the preceding glacial period the Saalian. The upper two biozones,N2 and Nl, foretell of the onset and development of arctic climatic conditions and are referred to the Early and Middle WeichseUan.
30 Aug 1985
TL;DR: Culver et al. as mentioned in this paper constructed a computer file of all published distributional data (presence or absence) on the living and dead recent benthic foraminifera off the North American Pacific Coast (Oregon to Alaska) from 31 papers published since 1886.
Abstract: Culver, Stephen J., and Martin A. Buzas. Distribution of Recent Benthic Foraminifera off the North American Pacific Coast from Oregon to Alaska. Smithsonian Contributions to the Marine Sciences, number 26, pages 234, 139 figures, 2 tables, 1985.—A computer file of all published distributional data (presence or absence) on the living and dead recent benthic foraminifera off the North American Pacific Coast (Oregon to Alaska) was constructed from 31 papers published since 1886. Manipulation of this file produced 5 catalogs and 139 maps. Catalog 1 lists alphabetically species names with publication and locality information as recorded in the literature (i.e., unsynonymized). Catalog 2 lists synonymized species names with publication and locality information. Catalogs 3 and 4 list alphabetically all unsynonymized and synonymized species names, respectively. Catalog 5 lists synonymized names by increasing latitude and longitude. During the past 100 years, 523 names have been used to record benthic foraminifera in the study area. Through synonymization, this number was reduced to 404, of which 138 occur at 6 or more of the 157 sample localities. Computer-generated maps were drawn for the 138 most commonly recorded species. Species were grouped by depth and geographic (latitudinal) distribution through visual examination of the maps. Eight species are coastal in their distribution, 63 occur mainly at depths of less than 200 m, 27 at depths greater than 200 m, and 40 are ubiquitous with depth. Many species appear to alter their depth distribution with latitude, but this may be due to a poor sampling framework. Latitudinally, the species are grouped into three categories. Forty-two species occur mainly to the north of 52°-55°N, 22 species occur mainly to the south of 52°-55°N, and 74 species are latitudinally ubiquitous within the area of study. This preliminary analysis indicates a possible faunal break in the region of Queen Charlotte Island. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: Seascape along the Atlantic coast of eastern North America. Library of Congress Cataloging in Publication Data Culver, Stephen J. Distribution of recent benthic foraminifera off the North American Pacific coast from Oregon to Alaska. (Smithsonian contributions to the marine sciences ; no. 26) Bibliography: p. Includes index. Supt. of Docs, no.: SI 1.41:26 1. Foraminifera—Pacific Coast (U.S.)—Geographical distribution. 2. Foraminifera—Pacific Coast (B.C.)—Geographical distribution. 3. Protozoa—Geographical distribution. 4. Protozoa—Pacific Coast (U.S.)—Geographical distribution. 5. Protozoa—Pacific Coast (B.C.)—Geographical distribution. I. Buzas, Martin A. II. Title. III. Series. QL368.F6C624 1985 593.1'209795 85-600001