A High-resolution Investigation of the Eocene-Oligocene Climate Transition PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A High-resolution Investigation of the Eocene-Oligocene Climate Transition PDF full book. Access full book title A High-resolution Investigation of the Eocene-Oligocene Climate Transition by Max Johan Holmstrom. Download full books in PDF and EPUB format.
Author: Max Johan Holmstrom
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Max Johan Holmstrom
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Donald R. Prothero
Publisher: Columbia University Press
ISBN: 0231127162
Category : Eocene-Oligocene boundary
Languages : en
Pages : 558
Get Book Here
Book Description
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.
Author: Donald R. Prothero
Publisher: Columbia University Press
ISBN: 9780231080910
Category : Science
Languages : en
Pages : 314
Get Book Here
Book Description
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
Author: Robert B. Gillham
Publisher:
ISBN:
Category : Eocene-Oligocene boundary
Languages : en
Pages : 146
Get Book Here
Book Description
Marine records show major cooling during the Eocene-Oligocene Climate Transition (EOCT). Most proxy studies in the White River Group suggest drying across the EOCT, and some suggest cooling. The lower resolution continental record has hindered a direct correlation of the marine climate record to Nebraska. I explore various correlation schemes and what they imply for faunal changes. This study compiles and analyzes data from 4,875 specimens in the University of Nebraska State Museum (UNSM) collection to test the hypothesis that climate change across the Eocene-Oligocene (E-O) boundary caused significant abundance changes in mammals. A series of binning schemes was created. One binning scheme followed previously established lithological zones, two schemes were based on average sediment accumulation rates, and three more were created by applying a cubic spline curve to published 206Pb/238U zircon ash dates. For the purpose of correlating the marine and Toadstool sections, I constructed a high-resolution (±0.5 m) carbon isotope stratigraphy across the E-O boundary using fossil enamel from the oreodont Merycoidodon. Results show that turnover in taxonomic abundance occurs throughout the study interval and is not concentrated across the EOCT. The largest pulse of faunal change and largest abundance changes for the most common taxa, Merycoidodon and the horse Mesohippus, slightly predate the EOCT. This raises the possibility that climate change began earlier in the continental interior than indicated by the marine benthic oxygen isotope record. Chord distance analyses reveal that the faunal composition of Orellan zones are more similar to one another than they are to the faunas of Chadron zones. This similarity is likely caused by the extinction, or near extinction, of Chadron taxa like Megacerops around the EOCT. Despite the lack of significant change in evenness, numerous taxa underwent extended changes in relative abundance through time. Archaeotherium, a water-dependent artiodactyl, decreased in relative abundance through time just as Poebrotherium, a water-independent camelid, increased in abundance through time. Changes in the relative abundances of Poebrotherium and Archaeotherium are consistent with a drier environment beginning in EOCT. The level of water-dependence in other taxa is less clear, and their changes in abundance cannot be confidently explained through diet, dentition, body mass, or locomotion.
Author: Donald R. Prothero
Publisher: Princeton University Press
ISBN: 1400862922
Category : Science
Languages : en
Pages : 583
Get Book Here
Book Description
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 editions preserve the original texts of these important books while presenting them in durable paperback and hardcover 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.
Author: Steven Michael Bohaty
Publisher:
ISBN:
Category :
Languages : en
Pages : 642
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The Eocene-Oligocene transition marks the passage from "greenhouse" conditions to an "icehouse state" with progressive global cooling starting in the early middle Eocene. The late Eocene is also characterized by a high concentration of extraterrestrial impacts, the effects of which, on living organisms and climatic changes, are still not understood. We carried out a high-resolution investigation on planktonic foraminiferal assemblages in an 8-m-thick segment of the Massignano global stratotype section and point for the Eocene-Oligocene boundary with the aim of assessing the effects that the impacts may have had on the environment and this group of organisms. The studied interval is punctuated by three late Eocene iridium-rich layers, several cosmic signatures, and enhanced levels of 3He. The two lower closely spaced iridium anomalies are possibly linked to the Popigai and Chesapeake Bay impact events, respectively, whereas no particular impact event can be assigned to the third anomaly, even if it might be correlated with some large craters. Interpretation of data suggests that all the impacts had no abrupt, dramatic effects on planktonic foraminifera. However, acting as forcing factors, they induced some environmental perturbations and may have contributed to remarkable climate changes superimposed on the general late Eocene cooling trend. The Popigai and Chesapeake Bay impact events triggered significant changes in the water mass structure, in terms of stratification and trophic resources, associated with some climatic excursions that took place within chron C16n.1n and chron C15r and at the transition between planktonic foraminiferal zones P15 and P16. The short-term warming pulse recognized after the Popigai impact might have been due to greenhouse effects produced by injection of CO2 into the atmosphere and/or the release of methane hydrate after the impact itself. The dynamic between hydrological and climate changes across the impactoclastic layers as observed.
Author: Donald R. Prothero
Publisher: Cambridge University Press
ISBN: 9780521021098
Category : Science
Languages : en
Pages : 708
Get Book Here
Book Description
The transition from the Eocene to the Oligocene epoch, occurring approximately 47 to 30 million years ago, was the most dramatic episode of climatic and biotic change since the demise of the dinosaurs. The mild tropical climates of the Paleocene and early Eocene were replaced by modern climatic conditions and extremes, including glacial ice in Antarctica. The first part of this book summarizes the latest information in the dating and correlation of the strata of late middle Eocene through early Oligocene age in North America. The second part reviews almost all the important terrestrial reptiles and mammals found near the Eocene-Oligocene boundary, in the White River Chronofauna--from the turtles, snakes and lizards to the common rodents, carnivores, oreodonts and deer of the Badlands. This is the first comprehensive treatment of these topics in over sixty years, and will be invaluable to vertebrate paleontologists, geologists, mammalogists and evolutionary biologists.
Author: Victoria Emma Taylor
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author:
Publisher:
ISBN: 9781339161020
Category :
Languages : en
Pages : 101
Get Book Here
Book Description
The middle Eocene is a transitional period from the greenhouse early Eocene to the ice-house Eocene-Oligocene Transition. Due to lack of high-resolution records, the details of this long-term cooling trend are not clear. Low-resolution atmospheric CO2 records suggest declining, but highly variable levels during the middle Eocene which might have driven transient climate variations. However, high-resolution stable isotope records are lacking to document the true climate patterns over this period. Moreover, orbital scale climate reconstructions are essential for reconciling how the sensitivity to orbital forcing changed, if at all, as the greenhouse boundary conditions changes from the early to late Eocene. High-resolution isotope and trace metal records are also essential for constraining the evolution of northern hemispheric sea-ice and continental glaciation as well as North Atlantic Deep Water in the middle Eocene.
