Download or read book Fluvial Response to Abrupt Global Warming at the Palaeocene Eocene Boundary written by Brady Z. Foreman and published by . This book was released on 2012 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluvial Response to the Paleocene Eocene Thermal Maximum in Western North America written by Brady Z. Foreman and published by . This book was released on 2013 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Paleocene-Eocene boundary ca. 56 million years ago is characterized by an extreme global warming event, known as the Paleocene-Eocene Thermal Maximum (PETM). The event is linked to the massive exogenic release of isotopically-light carbon into Earth's oceans and atmosphere, and is recognizable in the geologic record by an abrupt negative carbon isotope excursion in both organic and inorganic proxy records for duration of approximately 200,000 years. Previous studies indicate the PETM instigated massive changes in ocean and atmospheric circulation, which perturbed both terrestrial and marine environmental conditions and biotic systems. This study exploits the PETM to examine the effects of abrupt climate change on fluvial stratigraphy. The negative carbon isotope excursion associated with the PETM allows the timing and duration of the climate change to be identified independent of lithostratigraphic markers. Local climate shifts are constrained using circulation models, soil geochemistry, and paleobotanical records. Two areas are studied in detail, the Piceance Creek Basin of Colorado and the northern Bighorn Basin of Wyoming. In both areas anomalously thick and laterally persistent fluvial sand-bodies correlate with the PETM interval. In the Piceance Creek Basin the shift in fluvial deposition directly correlates with the onset of the PETM and persists beyond the carbon isotope excursion, whereas in the northern Bighorn Basin the shift appears to lag the isotope excursion by 10-20 thousand years and ends prior to the return to background climatic conditions. In the Piceance Creek Basin the change in sand-body geometry is associated with a shift to deeper paleoflow depths, wider channels, greater preservation of upper flow regime structures, prevalent crevasse splay deposits, and poorer drained floodplain soils. In contrast, within the Bighorn Basin there are no such changes and, apart from greater amalgamation, fluvial deposition appears to be largely unaffected by the PETM. When combined with other PETM terrestrial localities, the records demonstrate the PETM had substantial, but spatially diverse effects on basin-scale grain-size partitioning, discharge regimes, and river-floodplain dynamics. Aspects of the responses in the various basins are reminiscent of those predicted by two-dimensional basin-fill models, however, key differences highlight the role non-linearities, feedback loops, relaxation times, basin geometry, seasonality of precipitation, and vegetation factors play in determining large-scale depositional patterns. Consequently, it is concluded that short-term climatic events such as the PETM hold the potential to strongly alter basin sedimentation patterns, but that the sedimentologic-recorded climatic signal cannot be used to directly reconstruct paleoclimatic conditions. Instead a more appropriate approach is advocated that uses fluvial stratigraphy in concert with geochemical and other proxies to iteratively produce a more robust image of paleolandscape dynamics.
Download or read book Evaluating Thresholds in Fluvial Response to the Eocene Thermal Maximum 2 in the Bighorn Basin Wyoming U S A written by Grace Marie Sutherland and published by . This book was released on 2021 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth's climate experienced a set of hyperthermal events during the greenhouse climate state of the early Paleogene. The Paleocene-Eocene Thermal Maximum (PETM) was the largest of these abrupt global warming events, occurring at ~56 Ma and lasting for ~200,000 years. The PETM is identifiable by a large negative carbon isotope excursion and associated with significant changes in global temperature, hydrology, ocean chemistry, and biology. Subsequent smaller hyperthermal events appear to have commensurately smaller effects on marine environments, but the scaling of the complementary nonmarine environmental responses is unclear. The Bighorn Basin of northwest Wyoming contains the most detailed nonmarine record of the PETM, and recent work has identified a significant perturbation of fluvial deposition associated with it. The PETM generated a thick and laterally extensive sandbody likely due to enhanced channel mobility potentially mediated by higher sediment flux related to an increase in rainfall variability. This study compares and contrasts fluvial deposition spanning a younger hyperthermal event at ~53 Ma, the ETM2 event, which was approximately 50,000 years in duration and displays a carbon isotope excursion with half the magnitude of the PETM. Herein I present sandbody geometries, lithofacies patterns, flow depths, and paleocurrent patterns spanning the ETM2 for comparison to PETM-induced fluvial changes. I find channel-fills are dominated by fining upward sequences of trough crossbedding and ripple cross lamination and abundant bar clinoform deposition. Sandbodies are typically single-storied and 3 meters in thickness. Notably, there are no significant changes in fluvial deposition across the ETM2. Several hypotheses may explain this observation: (1) there were no major hydrologic changes associated with the ETM2; (2) there were no major changes in vegetation associated with the ETM2; and/or (3) environmental perturbations were insufficient to overcome the internal autogenic thresholds of the river systems. These three hypotheses are not mutually exclusive, and each is evaluated in the context of existing datasets.
Download or read book Fluvial Depositional Systems written by Andrew Miall and published by Springer Science & Business Media. This book was released on 2013-08-23 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended to complement the author's 1996 book "The geology of fluvial deposits", not to replace it. The book summarizes methods of mapping and interpretation of fluvial depositional systems, with a detailed treatment of the tectonic, climatic and eustatic controls on fluvial depositional processes. It focuses on the preserved, ancient depositional record and emphasizes large-scale (basin-scale) depositional processes. Tectonic and climatic controls of fluvial sedimentation and the effects of base-level change on sequence architecture are discussed. Profusely illustrated and with an extensive reference to the recent literature, this book will be welcomed by the student and professional geologist alike.
Download or read book Applications of Non Pollen Palynomorphs written by F. Marret and published by Geological Society of London. This book was released on 2021-10-29 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This long-awaited book about non-pollen palynomorphs (NPPs) aims to cover gaps in our knowledge of these abundant but understudied palynological remains. NPPs, such as fungal spores, testate amoebae, dinoflagellate cysts, acritarchs and animal remains, are routinely recovered from palynological preparations of marine or terrestrial material, from Proterozoic to recent geological times. This book gives the reader a comprehensive overview of the different types of NPPs, with examples from diverse time periods and environments. It provides guidance on sample preparation to maximize the recovery of these NPPs, detailed information on their diversity and ecological affinity, clarification on the nomenclature and demonstrates their value as environmental indicators. This volume will become the reference guide for any student, academic or practitioner interested in everything else in their palynological preparations.
Download or read book Earth s Evolving Systems written by Martin and published by Jones & Bartlett Learning. This book was released on 2016-12-16 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth’s Evolving Systems: The History of Planet Earth, Second Edition is an introductory text designed for popular courses in undergraduate Earth history. Written from a “systems perspective,” it provides coverage of the lithosphere, hydrosphere, atmosphere, and biosphere, and discussion of how those systems interacted over the course of geologic time.
Download or read book Stratigraphy and Paleolimnology of the Green River Formation Western USA written by Michael Elliot Smith and published by Springer. This book was released on 2015-07-02 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a suite of detailed stratigraphic and sedimentologic investigations of the Eocene Green River Formation of Wyoming, Colorado and Utah, one of the world’s foremost terrestrial archives of lacustrine and alluvial deposition during the warmest portion of the early Cenozoic. Its twelve chapters encompass the rich and varied record of lacustrine stratigraphy, sedimentology, geochronology, geochemistry and paleontology. Chapters 2-9 provide detailed member-scale synthesis of Green River Formation strata within the Greater Green River, Fossil, Piceance Creek and Uinta Basins, while its final two chapters address its enigmatic evaporite deposits and ichnofossils at broad, interbasinal scale.
Download or read book Sedimentary System Responses to External Forcings a Process Based Perspective written by Brian W. Romans and published by Frontiers Media SA. This book was released on 2020-12-01 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Download or read book Hydrogeology Chemical Weathering and Soil Formation written by Allen Hunt and published by John Wiley & Sons. This book was released on 2021-04-06 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores soil as a nexus for water, chemicals, and biologically coupled nutrient cycling Soil is a narrow but critically important zone on Earth's surface. It is the interface for water and carbon recycling from above and part of the cycling of sediment and rock from below. Hydrogeology, Chemical Weathering, and Soil Formation places chemical weathering and soil formation in its geological, climatological, biological and hydrological perspective. Volume highlights include: The evolution of soils over 3.25 billion years Basic processes contributing to soil formation How chemical weathering and soil formation relate to water and energy fluxes The role of pedogenesis in geomorphology Relationships between climate soils and biota Soils, aeolian deposits, and crusts as geologic dating tools Impacts of land-use change on soils The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about this book from this Q&A with the Editors
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 Dawn of the Age of Mammals in the Northern Part of the Rocky Mountain Interior North America written by Thomas M. Bown and published by Geological Society of America. This book was released on 1990 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Increased Hydrologic Variability Near the Paleocene Eocene Boundary Piceance Creek Basin Colorado U S A written by Anna Lesko and published by . This book was released on 2019 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Paleocene Eocene Thermal Maximum (PETM) was a rapid global warming event that occurred approximately 56 million years ago and represents the largest and most abrupt warming event of the Cenozoic Era. The PETM caused mean annual temperatures to increase at least 5°C globally above the already warm, greenhouse climate state of the early Paleogene. The warming and associated perturbation of the carbon cycle had numerous consequences for paleoenvironments and paleobiologic systems. This study investigates the hydrologic response to the PETM within the interior of North America and presents a new d13C bulk organic record. This study generates reconstructions of floodplain drainage and paleo-precipitation in the Piceance Creek Basin of northwest Colorado (U.S.A.). A semi-quantitative soil morphology index was used to characterize floodplain drainage and whole-rock geochemistry in order to estimate mean annual precipitation from a 124-meter stratigraphic section in the western portion of the Piceance Creek Basin. The section can be roughly litho- and bio-stratigraphically correlated to isotopically, well-constrained PETM stratigraphic intervals. The new bulk organic d13C record exhibits a range of values with an average of -22.3‰ ± 0.9 (1s). Variability in d13C values does not appear to be related to the amount of carbon nor lithology sample. Up-section there is a 40-meter thick interval over which d13C values shift ~2‰ to lower values and then return to baseline values. This interval corresponds to the lateral equivalent of the lower portion of the Molina Member, which is known to correlate with PETM. This study suggests the new isotopic record documents the PETM, but additional isotopic and biostratigraphic work needs to be performed to confirm. Within the hypothesized PETM interval soil morphology indices double in the upper portion of the structured isotopic shift, which indicates transiently better drainage in the floodplain. Mean annual precipitation (MAP) estimates from soil geochemistry are ~1500 mm/year before and after the isotopic excursion, and values as low as ~500 mm/year associated with the upper portion of the isotopic shift. This represents a 40% to 60% decrease in MAP in the basin. These results document greater drying in the Piceance Creek Basin as compared to the well-studied Bighorn Basin in northwest Wyoming wherein previous studies documented an increase in the soil morphology by 80% and decrease in MAP by 30-40% using identical methodologies as well as paleofloral records. When combined with other regional proxy datasets the results are consistent with general circulation model outputs that indicate widespread drying within the continental interior of North America as well as increased variability within the hydrologic cycle during the PETM. Moreover, this study supports the hypothesis that an enhanced hydrologic cycle is a robust response by the climate system to elevated atmospheric pCO2 levels, whether the carbon is ultimately sourced from anthropogenic sources or otherwise.
Download or read book Paleocene Flora of the Rocky Mountains and Great Plains written by Roland Wilbur Brown and published by . This book was released on 1962 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of 170 kinds of plants and the strata that yield them, showing how they apply in the delimination of the Paleocene series.
Download or read book Alluvial Fans written by Adrian M. Harvey and published by Geological Society of London. This book was released on 2005 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alluvial fans are important sedimentary environments. They trap sediment delivered from mountain source areas, and exert an important control on the delivery of sediment to downstream environments, to axial drainages and to sedimentary basins. They preserve a sensitive record of environmental change within the mountain source areas. Alluvial fan geomorphology and sedimentology reflect not only drainage basin size and geology, but change in response to tectonic, climatic and base-level controls. One of the challenges facing alluvial fan research is to resolve how these gross controls are reflected in alluvial fan dynamics and to apply the results of studies of modern fan processes and Quaternary fans to the understanding of sedimentary sequences in the rock record. This volume includes papers based on up-to-date research, and focuses on three themes: alluvial fan processes, dynamics of Quaternary alluvial fans and fan sedimentary sequences. Linking the papers is an emphasis on the controls of fan geomorphology, sedimentology and dynamics. This provides a basis for integration between geomorphological and sedimentological approaches, and an understanding how fluvial systems respond to tectonic, climatic and base-level changes.
Download or read book Extreme Past Climate Phytoplankton Response to Early Aptian and Paleocene eocene Boundary Greenhouse Conditions written by Fabrizio Tremolada and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mantle Convection and Surface Expressions written by Hauke Marquardt and published by John Wiley & Sons. This book was released on 2021-07-07 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multidisciplinary perspective on the dynamic processes occurring in Earth's mantle The convective motion of material in Earth's mantle, powered by heat from the deep interior of our planet, drives plate tectonics at the surface, generating earthquakes and volcanic activity. It shapes our familiar surface landscapes, and also stabilizes the oceans and atmosphere on geologic timescales. Mantle Convection and Surface Expressions brings together perspectives from observational geophysics, numerical modelling, geochemistry, and mineral physics to build a holistic picture of the deep Earth. It explores the dynamic processes occurring in the mantle as well as the associated heat and material cycles. Volume highlights include: Perspectives from different scientific disciplines with an emphasis on exploring synergies Current state of the mantle, its physical properties, compositional structure, and dynamic evolution Transport of heat and material through the mantle as constrained by geophysical observations, geochemical data and geodynamic model predictions Surface expressions of mantle dynamics and its control on planetary evolution and habitability The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book The Gulf of Mexico Sedimentary Basin written by John W. Snedden and published by Cambridge University Press. This book was released on 2019-11-21 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and richly illustrated overview of the Gulf of Mexico Basin, including its reservoirs, source rocks, tectonics and evolution.
