An Investigation Of The Oceanic Redistribution Of Carbon During The Last Deglaciation, 2010 University of Colorado, Boulder
An Investigation Of The Oceanic Redistribution Of Carbon During The Last Deglaciation, Sean Patrick Bryan
Geological Sciences Graduate Theses & Dissertations
Records from ice and marine sediment cores have revealed significant changes in the
ocean and atmospheric carbon reservoirs at the end of the last glacial period: atmospheric CO2 concentrations increased by ~50%, the atmospheric radiocarbon activity (Δ14C) declined by 190‰, the Δ14C of intermediate depth waters in the eastern North Pacific Ocean became extremely low relative to the contemporaneous atmosphere, and planktic foraminifera in the tropical and southern high latitude oceans experienced a negative excursion in δ13C. A promising theory for explaining these changes involves increased storage of carbon in the deep ocean during ...
Late Devonian Spermatophyte Diversity And Paleoecology At Red Hill, North-Central Pennsylvania, U.S.A., 2010 West Chester University
Late Devonian Spermatophyte Diversity And Paleoecology At Red Hill, North-Central Pennsylvania, U.S.A., Walter L. Cressler Iii, Cyrille Prestianni, Ben A. Lepage
Earth & Space Sciences Faculty Publications
No abstract provided.
Terrestrialization In The Late Devonian: A Palaeoecological Overview Of The Red Hill Site, Pennsylvania, Usa, 2010 West Chester University of Pennsylvania
Terrestrialization In The Late Devonian: A Palaeoecological Overview Of The Red Hill Site, Pennsylvania, Usa, Walter L. Cressler Iii, Edward B. Daeschler, Rudy Slingerland, Daniel A. Peterson
Earth & Space Sciences Faculty Publications
No abstract provided.
A Geographic Information Systems Approach To The 19th Century Excavation Of Brixham Cavern, Devon, England, 2010 Claremont McKenna College; Pitzer College; Scripps College
A Geographic Information Systems Approach To The 19th Century Excavation Of Brixham Cavern, Devon, England, Donald A. Mcfarlane, Joyce Lundberg, Warren Roberts
WM Keck Science Faculty Papers
The oldest known spatially-explicit archaeological excavation, conducted in Brixham cave, Devon, in 1858, is reconstructed using geographic information systems technology. Two dimensional plots of individual fossil taxa and flint artefacts demonstrate the utility of the technique for elucidating taphonomy and palaeobiology. The cave served as a den for hibernating brown bears, as a den for hyena and cave lion, and as a reliquary for their prey.
Ancient Dna Analyses Exclude Humans As The Driving Force Behind Late Pleistocene Musk Ox (Ovibos Moschatus) Population Dynamics, Paula F. Campos, Eske Willerslev, Andrei Sher, Ludovic Orlando, Erik Axelsson, Alexei Tikhonov, Kim Aaris-Sorensen, Alex D. Greenwood, Ralf-Dietrich Kahlke, Pavel Kosintsev
Biological Sciences Faculty Publications
The causes of the late Pleistocene megafaunal extinctions are poorly understood. Different lines of evidence point to climate change, the arrival of humans, or a combination of these events as the trigger. Although many species went extinct, others, such as caribou and bison, survived to the present. The musk ox has an intermediate story: relatively abundant during the Pleistocene, it is now restricted to Greenland and the Arctic Archipelago. In this study, we use ancient DNA sequences, temporally unbiased summary statistics, and Bayesian analytical techniques to infer musk ox population dynamics throughout the late Pleistocene and Holocene. Our results reveal ...
Exploring Isotopic Signatures Of Lake El'gygytgyn Sediments For Evidence Of Anoxia And Methane Cycling Over The Past 50,000 Years, 2010 University of Massachusetts Amherst
Exploring Isotopic Signatures Of Lake El'gygytgyn Sediments For Evidence Of Anoxia And Methane Cycling Over The Past 50,000 Years, Addie R. Holland
Masters Theses 1911 - February 2014
Compound specific isotope analysis of lake sediments is a powerful tool in deciphering evidence of changing climatic and paleoenvironmental conditions through time. Isotopic analysis of Lake El’gygytgyn pilot sediment cores, PG1351 and LZ1029, have contributed increased insight into paleoenvironmental interpretations regarding conditions of permanent ice cover and water column anoxia at the lake over the past 250 kyr. Bulk sediment δ15N was measured as a proxy for denitrification and a possible indicator for water column anoxia intensity. However, it appears that insufficient quantities of water column nitrate to fuel denitrification make its correlation with anoxia intensity ineffective. In pilot ...
Applying Paleolimnological Techniques To Sub-Tropical East Australian Estuaries, 2010 Southern Cross University
Applying Paleolimnological Techniques To Sub-Tropical East Australian Estuaries, Brendan Logan
This thesis examines the application of paleolimnological techniques, pioneered and developed predominately in northern hemisphere freshwater environments, to sub-tropical east Australian estuaries. The aim of this research was to determine how successfully these techniques - in particular those related to coring, dating, diatom analysis and stable isotope analysis – can be either applied or adapted to the estuarine environment to reconstruct nutrient levels in the absence of monitoring data. This will allow pre-impact environmental conditions of estuaries to be determined, which in turn will aid future management decisions.
Fifty-two estuaries from a spatially large geographic area were initially sampled, to create a ...
Integrating Social And Environmental Change In Prehistory: A Discussion Of The Role Of Landscape As A Heuristic In Defining Prehistoric Possibilities In Ne Thailand, William E. Boyd, Nigel Chang
School of Environment, Science and Engineering Papers
The archaeological study of past societies is an inherently difficult activity. Relying on extremely small samples of the available evidence, often many millennia after the event, archaeologists have the unenviable task of inferring complex relationships and processes for societies whose social, cultural, political and cognitive characteristics are likely to be very different from those of the archaeologists investigating them. Consequently, archaeologists are developing and adopting an increasingly wide range of analytical and conceptual tools with which to tackle the task of unravelling past social behaviour and history. While palaeoenvironmental study has frequently been called upon, it has largely been to ...
An Analysis Of Anchitherine Equids Across The Eocene–Oligocene Boundary In The White River Group Of The Western Great Plains, 2010 University of Nebraska at Lincoln
An Analysis Of Anchitherine Equids Across The Eocene–Oligocene Boundary In The White River Group Of The Western Great Plains, David M. Masciale
Dissertations & Theses in Earth and Atmospheric Sciences
Anchitherine horses are a subfamily of equids that are abundantly represented in the late Eocene and early Oligocene of North America. This group has been heavily studied in the past, but important questions still remain. Some studies have focused on the Eocene-Oligocene boundary and have used these equids along with other taxa to study mammalian diet and climate change through this interval. I reexamine two anchitherine genera, Mesohippus and Miohippus, from stratigraphic sequences of the White River Group in western Nebraska and southwestern South Dakota. These sequences span the Chadronian (late Eocene), Orellan (early Oligocene), and Whitneyan (early Oligocene) North ...
Tetrapod Fauna Of The Lowermost Usili Formation (Songea Group, Ruhuhu Basin) Of Southern Tanzania, With A New Burnetiid Record, 2010 University of Washington - Seattle Campus
Tetrapod Fauna Of The Lowermost Usili Formation (Songea Group, Ruhuhu Basin) Of Southern Tanzania, With A New Burnetiid Record, Christian A. Sidor, Kenneth D. Angielczyk, D. Marie Weide, Roger M. H. Smith, Sterling J. Nesbitt, Linda A. Tsuji
Papers in the Earth and Atmospheric Sciences
Vertebrate fossils from the Ruhuhu Basin of southern Tanzania have been known for over 75 years, but the details of their stratigraphic distribution remain imperfectly understood. Recent fieldwork in the Upper Permian Usili Formation (Songea Group) has led to the discovery of a tetrapod assemblage in a conglomeratic unit at its base. The fossils are concentrated in matrix-supported intraformational clay pebble conglomerates interpreted as mass flow deposits in wide, shallow channels in the distal reaches of an alluvial fan. Included in this new collection are fossils representing the first record of a burnetiid therapsid from Tanzania. The anatomy of the ...