Late Cretaceous to Early Paleocene Climate and Sea-level Fluctuations
Late Cretaceous to Early Paleocene Climate and Sea-level Fluctuations

Author:

Publisher:

Published:

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

Climate and sea-level fluctuations across the Cretaceous- ertiary (K- ) transition in Tunisia were examined based on bulk rock and clay mineralogies, biostratigraphy and lithology in five sections (El Melah, El Kef, Elles, Ain Settara and Seldja) spanning from open marine to shallow inner neritic environments. Late Campanian to early Danian trends examined at El Kef and Elles indicate an increasingly more humid climate associated with sea-level fluctuations and increased detrital influx that culminates at the K- transition. This long-term trend in increasing humidity and runoff in the Tethys region is associated with middle and high latitude cooling. Results of short-term changes across the K- transition indicate a sea-level lowstand in the latest Maastrichtian about 25- 00 ka below the K- boundary with the regression marked by increased detrital influx at El Kef and Elles and a short hiatus at Ain Settara. A rising sea-level at the end of the Maastrichtian is expressed at Elles and El Kef by deposition of a foraminiferal packstone. A flooding surface and condensed sedimentation mark the K- boundary clay which is rich in terrestrial organic matter. The P0- 1a transition is marked by a sea-level lowstand corresponding to a short hiatus at Ain Settara where most of P0 is missing and a period of non-deposition and erosion in the lower part of P1a (64.95 Ma). At Seldja, P0 and possibly the topmost part of CF1 are missing. These sea-level fluctuations are associated with maximum humidity. These data suggest that in Tunisia, long-term environmental stresses during the last 500 ka before the K- boundary and continuing into the early Danian are primarily related to climate and sea-level fluctuations. Within this long-term climatic trend the pronounced warm and humid event within the latest Maastrichtian Zone CF1 may be linked to greenhouse conditions induced by Deccan volcanism. The absence of any significant clay mineral variations at or near the K- boundary and Ir a.

Cretaceous Climate Events and Short-Term Sea-Level Changes
Cretaceous Climate Events and Short-Term Sea-Level Changes

Author: M. Wagreich

Publisher: Geological Society of London

Published: 2020

Total Pages: 269

ISBN-13: 1786204746

DOWNLOAD EBOOK

Sea-level constitutes a critical planetary boundary for geological processes and human life. Sea-level fluctuations during major greenhouse phases are still enigmatic and strongly discussed in terms of changing climate systems. The geological record of the Cretaceous greenhouse period provides a deep-time view on greenhouse-phase Earthsystem processes that facilitates a much better understanding of the causes and consequences of global, geologically short-term, sea-level changes. In particualr, Cretaceous hothouse periods can serve as a laboratory to better understand a near-future greenhouse Earth. This volume presents high-resolution sea-level records from globally distributed sedimentary archives of the Cretaceous involving a large group of scientists from the International Geoscience Programme IGCP 609. Marine to non-marine sedimentary successions were analysed for revised age constraints, the correlation of global palaeoclimate shifts and sea-level changes, tested for climate-driven cyclicities, and correlated within a high-resolution stratigraphic framework of the Geological Timescale. For hothouse periods, the hypothesis of significant global groundwater-related sea-level change, i.e. aquifer-eustasy as a major process, is reviewed and substantiated.

Earth History and Palaeogeography
Earth History and Palaeogeography

Author: Trond H. Torsvik

Publisher: Cambridge University Press

Published: 2017

Total Pages: 329

ISBN-13: 1107105323

DOWNLOAD EBOOK

This book provides a complete Phanerozoic story of palaeogeography, using new and detailed full-colour maps, to link surface and deep-Earth processes.

Cretaceous Sea Level Rise
Cretaceous Sea Level Rise

Author: Mu Ramkumar

Publisher: Elsevier

Published: 2015-11-05

Total Pages: 70

ISBN-13: 0128093234

DOWNLOAD EBOOK

Cretaceous Sea Level Rise delves into the question of whether the observed short-term sea-level changes are regional (tectonic) or global (eustatic) and determines their possible relation to climate cycles; to assess the role of feedback mechanisms, i.e. thermal expansion/contraction of seawater, subsidence due to loading by water, changing vegetation of the Earth System and to investigate the relation of sea-level highs and lows to ocean anoxia and oxidation events, represented by black shales and oceanic red beds, and to evaluate the evidence for ephemeral glacial episodes or other climate events. Though research has been, and is being, conducted in these fields since the introduction of sea level cycles and sequence development concepts in the 1970"s, the available information is scattered. Cretaceous Sea Level Rise presents the current understanding and future directions of the research on Cretaceous sea level cycles in a single source, forming a reference work for beginners, graduates and postgraduates who are interested in this subject. Authored by an expert in Sea Level Rise, with over 15 years’ experience Concludes with a section that looks to the future of sea level change The only source to combine the current understanding and future directions of the research on Cretaceous sea level cycles in one place

Late Cretaceous and Cenozoic History of North American Vegetation
Late Cretaceous and Cenozoic History of North American Vegetation

Author: Alan Graham

Publisher: Oxford University Press

Published: 1999-03-25

Total Pages: 372

ISBN-13: 0195344375

DOWNLOAD EBOOK

This book is a unique and integrated account of the history of North American vegetation and paleoenvironments over the past 70 million years. It includes discussions of the modern plant communities, causal factors for environmental change, biotic response, and methodologies. The history reveals a North American vegetation that is vast, immensely complex, and dynamic.

Understanding Earth's Deep Past
Understanding Earth's Deep Past

Author: National Research Council

Publisher: National Academies Press

Published: 2011-08-02

Total Pages: 153

ISBN-13: 0309209196

DOWNLOAD EBOOK

There is little dispute within the scientific community that humans are changing Earth's climate on a decadal to century time-scale. By the end of this century, without a reduction in emissions, atmospheric CO2 is projected to increase to levels that Earth has not experienced for more than 30 million years. As greenhouse gas emissions propel Earth toward a warmer climate state, an improved understanding of climate dynamics in warm environments is needed to inform public policy decisions. In Understanding Earth's Deep Past, the National Research Council reports that rocks and sediments that are millions of years old hold clues to how the Earth's future climate would respond in an environment with high levels of atmospheric greenhouse gases. Understanding Earth's Deep Past provides an assessment of both the demonstrated and underdeveloped potential of the deep-time geologic record to inform us about the dynamics of the global climate system. The report describes past climate changes, and discusses potential impacts of high levels of atmospheric greenhouse gases on regional climates, water resources, marine and terrestrial ecosystems, and the cycling of life-sustaining elements. While revealing gaps in scientific knowledge of past climate states, the report highlights a range of high priority research issues with potential for major advances in the scientific understanding of climate processes. This proposed integrated, deep-time climate research program would study how climate responded over Earth's different climate states, examine how climate responds to increased atmospheric carbon dioxide and other greenhouse gases, and clarify the processes that lead to anomalously warm polar and tropical regions and the impact on marine and terrestrial life. In addition to outlining a research agenda, Understanding Earth's Deep Past proposes an implementation strategy that will be an invaluable resource to decision-makers in the field, as well as the research community, advocacy organizations, government agencies, and college professors and students.

Encyclopedia of Paleoclimatology and Ancient Environments
Encyclopedia of Paleoclimatology and Ancient Environments

Author: Vivien Gornitz

Publisher: Springer Science & Business Media

Published: 2008-10-31

Total Pages: 1062

ISBN-13: 1402045514

DOWNLOAD EBOOK

One of Springer’s Major Reference Works, this book gives the reader a truly global perspective. It is the first major reference work in its field. Paleoclimate topics covered in the encyclopedia give the reader the capability to place the observations of recent global warming in the context of longer-term natural climate fluctuations. Significant elements of the encyclopedia include recent developments in paleoclimate modeling, paleo-ocean circulation, as well as the influence of geological processes and biological feedbacks on global climate change. The encyclopedia gives the reader an entry point into the literature on these and many other groundbreaking topics.

The Vegetation of Antarctica through Geological Time
The Vegetation of Antarctica through Geological Time

Author: David J. Cantrill

Publisher: Cambridge University Press

Published: 2012-11-22

Total Pages: 489

ISBN-13: 113956028X

DOWNLOAD EBOOK

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.