Download or read book Late Paleogene Eocene to Oligocene Paleoceanography of the Northern North Atlantic written by and published by . This book was released on 1910 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I was supported in this work by the United States Navy, Office of Naval Research under contract N00014-79-C-0071 and a graduate fellowship from PHILLIPS Petroleum and the Woods Hole Oceanographic Institution Education Office.

Download or read book Late Paleogene Eocene to Oligocene paleoceanography of the northern North Atlantic written by Kenneth George Miller and published by . This book was released on 1982* with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic stratigraphic evidence indicates that a major change in abyssal circulation occurred in the latest Eocene-earliest Oligocene of the North Atlantic. Reflector R4 reflects a change from weakly (Eocene) to vigorously circulating bottom water (early Oligocene). Sediment distribution studies indicate a northern source for this bottom water, probably from the Arctic via the Norwegian-Greenland Sea/Faeroe-Shetland Channel. Current-controlled sedimentation and erosion continued through the Oligocene; however, above reflector R3 (upper Oligocene), the general intensity of abyssal currents decreased. Above reflector R2 (lower Miocene) a further reduction in abyssal currents resulted in more coherent current-controlled sedimentation and a major phase of sediment drift development. Major deep-sea benthic foraminiferal changes occurred between the middle Eocene and earliest Oligocene: an agglutinated assemblage was replaced by a calcareous assemblage (abyssal Labrador Sea), and an indigenous Eocene calcareious fauna became extinct (abyssal Bay of Biscay). In shallower Atlantic sites (

Download or read book Middle Eocene to Early Oligocene Paleoceanography of the Southern Ocean written by Steven Michael Bohaty and published by . This book was released on 2006 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geology of the Atlantic Ocean written by Kenneth O. Emery and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1063 pages. Available in PDF, EPUB and Kindle. Book excerpt: The explosion of interest, effort, and information about the ocean since about 1950 has produced many thousand scientific articles and many hun dred books. In fact, the outpouring has been so large that authors have been unable to read much of what has been published, so they have tended to concentrate their own work within smaller and smaller subfields of oceanog raphy. Summaries of information published in books have taken two main paths. One is the grouping of separately authored chapters into symposia type books, with their inevitable overlaps and gaps between chapters. The other is production of lightly researched books containing drawings and tables from previous pUblications, with due credit given but showing assem bly-line writing with little penetration of the unknown. Only a few books have combined new and previous data and thoughts into new maps and syntheses that relate the contributions of observed biological, chemical, geological, and physical processes to solve broad problems associated with the shape, composition, and history of the oceans. Such a broad synthesis is the objective of this book, in which we tried to bring together many of the pieces of research that were deemed to be of manageable size by their originators. The composite may form a sort of plateau above which later studies can rise, possibly benefited by our assem bly of data in the form of new maps and figures.

Download or read book Western North Atlantic Palaeogene and Cretaceous Palaeoceanography written by Geological Society of London and published by Geological Society of London. This book was released on 2001 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Palaeogene and Cretaceous palaeoceanography has been the focus of intense international interest in the last few years, spurred by deep ocean drilling at Blake Nose in the North Atlantic as well as the need to use past climate change as input for modelling future climate change. This book brings together a number of review papers that describe ancient oceans and unique events in the Earth's climatic history and evolution of biota. The papers show evidence of periods characterized by exceptional global warmth such as the Late Palaeocene Thermal Maximum and Cretaceous anoxic events. Geochemical records and modelling will make the reader aware that these periods were forced by greenhouse gases.

Download or read book South Atlantic Paleoceanography written by K. J. Hsu and published by Cambridge University Press. This book was released on 1985-11-07 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the findings made in the late 1970s and 80s about the history of the South Atlantic Ocean.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1983 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eocene Oligocene Climatic and Biotic Evolution written by Donald R. Prothero and published by . This book was released on 1992 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transition from the Eocene to the Oligocene epochs was the most significant event in earth history since the extinction of dinosaurs. As the first Antarctic ice sheets appeared, major extinctions and faunal turnovers took place on the land and in the sea, eliminating forms adapted to a tropical world and replacing them with the ancestors of most of our modern animal and plant life. Through a detailed study of climatic conditions and of organisms buried in Eocene-Oligocene sediments, this volume shows that the separation of Antarctica from Australia was a critical factor in changing oceanic circulation and ultimately world climate. In this book forty-eight leading scientists examine the full range of Eocene and Oligocene phenomena. Their articles cover nearly every major group of organisms in the ocean and on land and include evidence from paleontology, stable isotopes, sedimentology, seismology, and computer climatic modeling. The volume concludes with an update of the geochronologic framework of the late Paleogene. Originally published in 1992. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

Download or read book The Eocene Oligocene Transition written by Donald R. Prothero and published by Columbia University Press. This book was released on 1994 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: After a decade of new findings and interpretation based on innovative techniques during the 1980s, archaeologists were pretty sure that 38 million years ago the earth still basked in a subtropical "greenhouse" that had lasted since the age of dinosaurs, but 5 million years later there were glaciers in the Antarctic, signalling the beginning of the "icehouse" state that we know now. Here is a summary of the present understanding of the climatic and biological changes, for nonspecialists who have some familiarity with the terms and concepts of archaeology. Paper edition (08091-3), $24. Annotation copyright by Book News, Inc., Portland, OR

Download or read book The Vegetation of Antarctica through Geological Time written by David J. Cantrill and published by Cambridge University Press. This book was released on 2012-11-22 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fossil history of plant life in Antarctica is central to our understanding of the evolution of vegetation through geological time and also plays a key role in reconstructing past configurations of the continents and associated climatic conditions. This book provides the only detailed overview of the development of Antarctic vegetation from the Devonian period to the present day, presenting Earth scientists with valuable insights into the break up of the ancient supercontinent of Gondwana. Details of specific floras and ecosystems are provided within the context of changing geological, geographical and environmental conditions, alongside comparisons with contemporaneous and modern ecosystems. The authors demonstrate how palaeobotany contributes to our understanding of the paleoenvironmental changes in the southern hemisphere during this period of Earth history. The book is a complete and up-to-date reference for researchers and students in Antarctic paleobotany and terrestrial paleoecology.

Download or read book The Miocene Ocean written by James P. Kennett and published by Geological Society of America. This book was released on 1985 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Greenhouse to Icehouse written by Donald R. Prothero and published by Columbia University Press. This book was released on 2003 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: The marine Eocene-Oligocene transition of 34 million years ago was a critical turning point in Earth's climatic history, when the warm, high-diversity "greenhouse" world of the early Eocene ceded to the glacial, "icehouse" conditions of the early Oligocene. This book surveys the advances in stratigraphic and paleontological research and isotopic analysis made since 1989 in regard to marine deposits around the world. In particular, it summarizes the high-resolution details of the so-called doubthouse interval (roughly 45 to 34 million years ago), which is critical to testing climatic and evolutionary hypotheses about the Eocene deterioration. The authors' goals are to discuss the latest information concerning climatic and oceanographic change associated with this transition and to examine geographic and taxonomic patterns in biotic turnover that provide clues about where, when, and how fast these environmental changes happened. They address a range of topics, including the tectonic and paleogeographic setting of the Paleogene; specific issues related to the stratigraphy of shelf deposits; advances in recognizing and correlating boundary sections; trends in the expression of climate change; and patterns of faunal and floral turnover. In the process, they produce a valuable synthesis of patterns of change by latitude and environment.

Download or read book The Terrestrial Eocene Oligocene Transition in North America written by Donald R. Prothero and published by Cambridge University Press. This book was released on 1996-06-13 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides the latest information in dating and correlation of the strata of late middle Eocene through early Oligocene age in North America.

Download or read book Cenozoic Deep water Agglutinated Foraminifera in the North Atlantic written by Michael Anthony Kaminski and published by . This book was released on 1987 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cenozoic (predominantly Paleogene) "flysch-type" agglutinated foraminiferal assemblages and their modern analogs in the North Atlantic and adjacent areas have been studied to provide an overview of their spatial and temporal distribution and utility for paleoenvironmental analysis. Over 200 species of agglutinated foraminifera have been recognized in Paleogene sediments from North Atlantic and Tethyan basins. This unified taxonomic data base enables the first general synthesis of biostratigraphic, paleobiogeographic and paleobathymetric patterns in flysch-type agglutinated assemblages from upper Cretaceous to Neogene sediments in the North Atlantic. The majority of taxa are cosmopolitan, but latitudinal, temporal and depth-related trends in diversity and species composition are observed among flysch-type assemblages. Modern deep-sea agglutinated foraminiferal faunas provide an analog to fossil flysch-type assemblages and serve as models for paleoecologic studies. Core-top samples from the Panama Basin, Gulf of Mexico and Nova Scotian continental rise were examined in order to determine the habitats of modern species of agglutinated foraminifera. The ecology of modern taxa provides constraints on the paleoenvironmental significance of fossil agglutinated assemblages in the North Atlantic, and their utility for paleoceanography. Towards this end, spade core samples from a 3912 m deep station in the Panama Basin were studied to determine abundance and microhabitat partitioning among living agglutinated foraminiferal populations and the preservation of dead assemblages. The genera Dendrophrya, Cribrostomoides and Ammodiscus have epifaunal habitats and the genus Reophax is predominantly infaunal. Species of Reophax are probably responsible for fine reticulate burrows observed in xradiographs. An experiment using recolonization trays in the Panama Basin was designed to identify opportunistic species of benthic foraminifera, and to assess the rate at which a population can colonize an abiotic substrate. The most successful colonizer at this site is Reophax, while Dendrophrya displays the lowest capability for dispersal. After nine months the abundance of living individuals in sediment trays was one-tenth to one-third that of background abundance, but the faunal diversity did not differ greatly from control samples. Recolonization by benthic foraminifera is more rapid than among macrofaunal invertebrates. Modern agglutinated assemblages from the Louisiana continental slope were examined to determine changes in species composition associated with hydrocarOrganic- bon seeps. rich substrates are characterized by a decrease in astrorhizids and an increase in trochamminids and textulariids. Highly organicenriched substrates with chemosynthetic macrofauna are dominated by Trochammina glabra and Glomospira charoides. The biostratigraphy of fossil agglutinated foraminifera in the North Atlantic is based on detailed analysis of 670 samples from 14 wells and one outcrop section, and examination of additional picked faunal slides from industry wells. Local biostratigraphic schemes are established for Trinidad, Northern Spain, the Labrador Sea, Baffin Bay, and the Norwegian-Greenland Sea. These schemes are compared with existing biostratigraphic frameworks from the Labrador Margin, the North Sea, and the Polish Carpathians. A number of species show utility for biostratigraphy in the North Atlantic. Lineages which contain stratigraphically useful species include the Haplophragmoides cf. glabra - Reticulophragmium group, Hormosina, and Karreriella. Significant faunal turnovers are observed at the Paleocene/Eocene, Ypresian/ Lutetian and Eocene/Oligocene boundaries. A reduction in diversity occurs at the Paleocene/Eocene boundary in all bathyal sections studied, and agglutinated forminifera disappear entirely from abyssal low-latitude DSDP sites. In the Gibraltar Arch, the Labrador Sea and the Norwegian-Greenland Sea, the Ypresian/Lutetian boundary is characterized by a Glomospira-facies. This is attributed to a rise in the lysocline associated with increased paleoproductivity and the NP14 sealevel lowstand. The Eocene/Oligocene boundary is delimited by another major turnover and the last occurrence of a number of important taxa. At Site 647, where recovery across the Eocene/Oligocene boundary was continuous, the change from an Eocene agglutinated assemblage to a predominantly calcareous assemblage in the early Oligocene took place gradually, over a period of about 4 m.y. The rate of change of the faunal turnover accelerated near the boundary. This faunal turnover is attributed to changes in the preservation of agglutinated foraminifera, since delicate species disappeared first. Increasingly poorer preservation of agglutinated foraminifera in the late Eocene to earliest Oligocene reflected the first appearance of cool, nutrient-poor deep water in the southern Labrador Sea. The approximately coeval disappearance of agglutinated assemblages along the Labrador Margin was caused by a regional trend from slope to shelf environments, accentuated by the "mid"--Oligocene sealevel lowstand. Paleobiogeographic patterns in flysch-type foraminifera were examined in the Paleogene of the North Atlantic. In the early Paleogene, general decrease in diversity is observed from low to high latitudes and from the continental slope to the deep ocean basins. The diversity of these microfossils declines in most studied sections throughout the Paleogene. The last common occurrence (LCO) of flysch-type foraminifera in the North Atlantic exhibits a pattern of diachrony with latitude and depth. Extinctions occurred first at abyssal depths and at low latitudes. Agglutinated assemblages disappeared from the northern Atlantic region in the early Oligocene. However, the deep Norwegian-Greenland Sea served as a refuge for many species, and agglutinated assemblages persisted there until the early Pliocene. The LCO of flysch-type foraminifera may have been related to the transition from a warm, sluggish deep sea environment to a cooler, more oxygenated, thermohaline-driven deep circulation pattern caused by bipolar cooling. The paleobathymetry of Paleogene agglutinated assemblages in the North Atlantic differs from Cretaceous patterns. Shallow-water assemblages of Paleogene age contain robust astrorhizids, loftusiids and coarse lituolids, whereas deep assemblages possess delicate tubular forms, ammodiscids, and smooth lituolids. At low latitudes, upper bathyal assemblages contain abundant calcareous ataxophragmiids. Paleocene paleobathymetric patterns in the North Atlantic compare well with patterns observed in the Carpathian troughs. The utility of agglutinated foraminifera in paleoceanography is illustrated by a study of the paleocommunity structure of fossil assemblages in ODP Hole 646B on the Eirik Ridge (Labrador Sea). The synecology of benthic foraminifera in Hole 646B places constraints on the history of Denmark Straits Overflow Water over that site. Below seismic horizon "R3", a Miocene assemblage contains smooth agglutinated species with abundant Nuttalides umbonifera, indicating corrosive bottom water and tranquil conditions. A coarse agglutinated assemblage with "NADW-type" calcareous benthics is observed above the seismic horizon. This faunal turnover at horizon "R3" reflects the onset (or renewal) of significant Denmark Straits overflow at -7.5 Ma. Agglutinated species disappear between reflector "R2", and the base of the sediment drift, indicating a change in deep-water properties associated with the re-opening of the Mediterranean. The onset of drift sedimentation at the Eirik Ridge is dated at -4.5 Ma. Drift formation ceased at -2.5 Ma, concomitant with the appearance of ice-rafted sediments.

Download or read book 1982 Summer Study Program in Geophysical Fluid Dynamics written by Woods Hole Oceanographic Institution and published by . This book was released on 1982 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tracings: 91.40.

Download or read book North Atlantic Palaeoceanography written by C. P. Summerhayes and published by . This book was released on 1986 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Eocene Oligocene paleoceanography in the Antarctic Ocean Atlantic sector Maud Rise ODP Leg 113 Site 689B and 690B written by L. DIESTER-HAASS and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: