Publications
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Inorganic and organic geochemistry of Eocene to Cretaceous strata recovered from the lower continental rise, North American Basin, Site 603, Deep Sea Drilling Project Leg 93
About one hundred samples of sediments and rocks recovered in Hole 603B were analyzed for type, abundance, and isotopic composition of organic matter, using a combination of Rock-Eval pyrolysis, C-H-N-S elemental analysis, and isotope-ratio mass spectrometry. Concentrations of major, minor, and trace inorganic elements were determined with a combination of X-ray fluorescence and induction-coupled
Authors
Walter E. Dean, M.A. Arthur
Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State
Douglas fir trees and associated soils were sampled from the slopes of a small (∼4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger branches or the trunk. The U concentration in needle ash ranges from 0.2 to 5.8μg g−1 (ppm) and shows no correla
Authors
R. A. Zielinski, R.R. Schumann
Rock-water interaction in ash-flow tuffs (Yucca Mountain, Nevada, USA)- The record from uranium studies
Forty-eight core samples of ash-flow tuffs from Yucca Mountain, NV, were selected for comparative analysis by uranium-based methods to estimate past interaction with oxidizing water. Results aid in the selection of hydrologically isolated host rocks for radioactive waste disposal. U abundances were consistently more variable than thorium in whole rocks, suggesting some selective redistribution of
Authors
Robert A. Zielinski, Charles A. Bush, R.W. Spengler, Barney J. Szabo
Impact of time and climate on Quaternary soils in the Yucca Mountain area of the Nevada Test Site
No abstract available.
Authors
Emily M. Taylor
Paleomagnetic evidence for the timing of collapse and resurgence of the Lake City Caldera, San Juan Mountains, Colorado
Rocks of the 23.1‐m.y.‐old Lake City caldera consist of the compositionally zoned Sunshine Peak Tuff, postcollapse intracaldera lava flows, and resurgent quartz syenite intrusions. Declinations of reversely magnetized (I = −45° to −75°) Sunshine Peak Tuff change from easterly (D = 93°–130°) throughout most of the tuff to southerly (D = 195°–207°) within the late eruptive phases. The postcollapse l
Authors
Richard L. Reynolds, Mark R. Hudson, Ken Hon
Stratigraphy and correlation of the glacial deposits on the Montana Plains
Till units representing at least three pre-Illinoian continental glaciations, at least one Illinoian glaciation, and a late Wisconsin glaciation have been identified on the Montana Plains. Early Wisconsin or middle Wisconsin till units have not been identified. The southernmost limit of late Wisconsin glaciation is in Montana, more than 170 km south of the Lethbridge moraine in Alberta, Canada (Fi
Authors
David S. Fullerton, Roger B. Colton
Introduction to quaternary glaciations in the United States of America
No abstract available.
Authors
Gerald M. Richmond, David S. Fullerton
Late Neogene and Quaternary coarse-fraction and carbonate stratigraphies for Site 586 on Ontong-Java Plateau and Site 591 on Lord Howe Rise
Carbonate oozes recovered by hydraulic piston coring at DSDP Site 586 on Ontong-Java Plateau and Site 591 on Lord Howe Rise have carbonate contents that are consistently higher than 90% with only minor variations. Consequently, paleoceanographic signals were not recorded in detail in the carbonate contents. However, mass accumulation rates of carbonate increased in the late Miocene to mid-Pliocene
Authors
J. V. Gardner, Walter E. Dean, Lynne Bisagno, Eileen Hemphill-Haley
Rhythmic bedding in Upper Cretaceous pelagic carbonate sequences: Varying sedimentary response to climatic forcing
Rhythmic bedding is a prominent feature of North American and European Upper Cretaceous pelagic carbonate sequences deposited in epicontinental and continental-edge settings. Such bedding rhythms can result from variations in carbonate productivity, terrigenous dilution, redox conditions, or bottom currents. Each type of bedding cycle is expressed differently in the stratigraphic record but probab
Authors
M.A. Arthur, D.J. Bottjer, Walter E. Dean, A.G. Fischer, D.E. Hattin, E.G. Kauffman, L.M. Pratt
Rhythmic bedding produced in Cretaceous pelagic carbonate environments: Sensitive recorders of climatic cycles
Various types of rhythmic bedding are prominent features of Cretaceous pelagic carbonates. These bedding rhythms are the primary depositional result of variations in carbonate productivity, terrigenous dilution, redox conditions and/or the energy of bottom currents. Each bedding cycle type is different in its expression in the stratigraphic record but ultimately was caused by rhythmic climatic var
Authors
D.J. Bottjer, M.A. Arthur, Walter E. Dean, D.E. Hattin, Charles Savrda