Publications
Filter Total Items: 1425
Geochemical expression of early diagenesis in middle Eocene-lower Oligocene pelagic sediments in the southern Labrador Sea, Site 647, ODP Leg 105 Geochemical expression of early diagenesis in middle Eocene-lower Oligocene pelagic sediments in the southern Labrador Sea, Site 647, ODP Leg 105
Geochemical analyses of the middle Eocene through lower Oligocene lithologic Unit IIIC (260-518 meters below sea floor [mbsf]) indicate a relatively constant geochemical composition of the detrital fraction throughout this depositional interval at Ocean Drilling Program (ODP) Site 647 in the southern Labrador Sea. The main variability occurs in redox-sensitive elements (e.g., iron...
Authors
M.A. Arthur, Walter E. Dean, J.C. Zachos, M. Kaminski, S. Hagerty Rieg, K. Elmstrom
Geochemical and paleoenvironmental variations across the Cretaceous/Tertiary boundary at Braggs, Alabama Geochemical and paleoenvironmental variations across the Cretaceous/Tertiary boundary at Braggs, Alabama
The Cretaceous/Tertiary (K/T) boundary in southern Alabama occurs in a sequence of interbedded shallow-marine limestones and marls deposited during a Late Maastrichtian regression and subsequent Danian transgression. The presence of a diverse assemblage of Cretaceous and Paleocene benthic micro- and macrofossils has allowed detailed examination of paleoenvironmental changes in this...
Authors
J.C. Zachos, Michael A. Arthur, Walter E. Dean
Changes in redox conditions in deep‐sea sediments of the subarctic North Pacific Ocean: Possible evidence for the presence of North Pacific Deep Water Changes in redox conditions in deep‐sea sediments of the subarctic North Pacific Ocean: Possible evidence for the presence of North Pacific Deep Water
Cores of upper Quaternary and Holocene sediment from the subarctic North Pacific north of about 48°N contain one or more layers of oxidized brown sediment interbedded within predominantly reduced green sediment. The brown layers are enriched in several trace elements, especially Mn, Mo, Ni, and Co, relative to the green layers. Where multiple oxidized layers are present, the intensity of...
Authors
Walter E. Dean, J. V. Gardner, Eileen Hemphill-Haley
Zircon geochronology of Precambrian rocks in southeastern Wyoming and northern Colorado Zircon geochronology of Precambrian rocks in southeastern Wyoming and northern Colorado
Archean gneisses and Early Proterozoic metasedimentary rocks of the Wyoming Province are separated from Proterozoic eugeoclinal metamorphic rocks by a major east-west–trending shear zone called the Cheyenne belt. U-Pb zircon ages of Archean tonalites north of the Cheyenne belt denote an intrusive event at 2,700 Ma. Detrital zircons from Proterozoic metasedimentary rocks north of the...
Authors
Wayne R. Premo, W. R. Van Schmus
Pb isotopes in Anorthositic Breccias 67075 and 62237: A search for primitive lunar lead Pb isotopes in Anorthositic Breccias 67075 and 62237: A search for primitive lunar lead
No abstract available.
Authors
Wayne R. Premo, M. Tatsumoto, J. W. Wang
Iron-sulfur-carbon relationships in organic-carbon-rich sequences I: Cretaceous Western Interior seaway Iron-sulfur-carbon relationships in organic-carbon-rich sequences I: Cretaceous Western Interior seaway
No abstract available.
Authors
Walter E. Dean, Michael A. Arthur
Morphology of Red Creek, Wyoming, an arid-region anastomosing channel system Morphology of Red Creek, Wyoming, an arid-region anastomosing channel system
The narrow, deep, and sinuous main channel is flanked by anastomosing flood channels, or anabranches. Most anabranches are initiated at meander bends. The primary mechanism of anabranch initiation is avulsion during overbank floods. -from Author
Authors
R.R. Schumann
Borax in the supraglacial moraine of the Lewis Cliff, Buckley Island quadrangle--first Antarctic occurrence Borax in the supraglacial moraine of the Lewis Cliff, Buckley Island quadrangle--first Antarctic occurrence
During the 1987-1988 austral summer field season, membersof the south party of the antarctic search for meteorites south-ern team* working in the Lewis Cliff/Colbert Hills region dis-covered several areas of unusual mineralization within theLewis Cliff ice tongue and its associated moraine field (figure1). The Lewis Cliff ice tongue (84°15'S 161°25'E) is a meteorite-stranding surface of...
Authors
J. J. Fitzpatrick, D.R. Muhs
Uranium-series ages, faunal correlations and tectonic deformation of marine terraces within the Agua Blanca fault zone at Punta Banda, northern Baja California, Mexico Uranium-series ages, faunal correlations and tectonic deformation of marine terraces within the Agua Blanca fault zone at Punta Banda, northern Baja California, Mexico
No abstract available.
Authors
T. K. Rockwell, D.R. Muhs, G. L. Kennedy, M.E. Hatch, S.M. Wilson, R.E. Klinger
Geologic map of the Trident Peak SW quadrangle, Humboldt County, Nevada Geologic map of the Trident Peak SW quadrangle, Humboldt County, Nevada
No abstract available.
Authors
Scott A. Minor, Michael Wager, Craig S. Harwood
U-Th-Pb, Sm-Nd, Rb-Sr, and Lu-Hf systematics of Returned Mars Samples U-Th-Pb, Sm-Nd, Rb-Sr, and Lu-Hf systematics of Returned Mars Samples
No abstract available.
Authors
M. Tatsumoto, Wayne R. Premo
Stratigraphic evidence of Holocene faulting in the mid-continent: The Meers fault, southwestern Oklahoma Stratigraphic evidence of Holocene faulting in the mid-continent: The Meers fault, southwestern Oklahoma
Stratigraphic relations and ten 14C ages show that movement occurred on the Meers fault in late Holocene time. Movement on the fault postdates the Browns Creek Alluvium, which began to be deposited between 14,000 and 13,000 yr B.P., and predates the East Cache Alluvium, which was deposited between 800 and 100 yr B.P. Surface warping along the fault led to local stream incision on the...
Authors
Richard F. Madole