Publications
Filter Total Items: 1492
Iron sulfide minerals at Cement oil field, Oklahoma: Implications for magnetic detection of oil fields Iron sulfide minerals at Cement oil field, Oklahoma: Implications for magnetic detection of oil fields
Aeromagnetic anomalies at Cement oil field (Anadarko basin, Oklahoma) have been attributed to authigenic magnetite. The following characteristics of the magnetite, however, indicate that it is contamination introduced by drilling: (1) occurrence as sharp angular blades and as spheres, commonly with metallographic textures typical of industrial alloys and with associated steel and wustite...
Authors
Richard L. Reynolds, Neil S. Fishman, Richard B. Wanty, Martin B. Goldhaber
Influence of climate and eolian dust on the major-element chemistry and clay mineralogy of soils in the northern Bighorn basin, U.S.A. Influence of climate and eolian dust on the major-element chemistry and clay mineralogy of soils in the northern Bighorn basin, U.S.A.
Soil chronosequences in the northern Bighorn basin permit the study of chronologic changes in the major-element chemistry and clay mineralogy of soils formed in different climates. Two chronosequences along Rock Creek in south-central Montana formed on granitic alluvium in humid and semiarid climates over the past two million years. A chronosequence at the Kane fans in north-central...
Authors
Marith C. Reheis
Saline minerals in the Lewis Cliff ice tongue, Buckley Island Quadrangle, Antarctica Saline minerals in the Lewis Cliff ice tongue, Buckley Island Quadrangle, Antarctica
No abstract available.
Authors
J. J. Fitzpatrick, D.R. Muhs, A.J.T. Jull
Stop 16: Trench 14 Stop 16: Trench 14
No abstract available.
Authors
Emily M. Taylor, John S. Stuckless, S. S. Levy
Geochemical evidence for suppression of pelagic marine productivity at the Cretaceous/Tertiary boundary Geochemical evidence for suppression of pelagic marine productivity at the Cretaceous/Tertiary boundary
The normal, biologically productive ocean is characterized by a gradient of the 13C/12C ratio from surface to deep waters. Here we present stable isotope data from planktonic and benthic micro-fossils across the Cretaceous/Tertiary boundary in the North pacific, which reveal a rapid and complete breakdown in this biologically mediated gradient. The fluxes of barium (a proxy for organic...
Authors
James Zachos, M.A. Arthur, Walter E. Dean
Source of anomalous magnetization in an area of hydrocarbon potential: Petrologic evidence from the Jurassic Preuss Sandstone, Wyoming-Idaho thrust belt Source of anomalous magnetization in an area of hydrocarbon potential: Petrologic evidence from the Jurassic Preuss Sandstone, Wyoming-Idaho thrust belt
The Jurassic Preuss Sandstone, which crops out in the central part of the Wyoming-Idaho thrust belt on trend with a hydrocarbon-producing region to the south, has been previously identified as the source of anomalous magnetization in the area. Elsewhere, anomalous magnetization in sedimentary rocks near hydrocarbon accumulations has been attributed to hydrocarbon-engendered magnetic...
Authors
Neil S. Fishman, Richard L. Reynolds, Mark R. Hudson, Vito F. Nuccio
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