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Full-Text Articles in Physical Sciences and Mathematics
Cooling History Of Atlantis Bank Oceanic Core Complex: Evidence For Hydrothermal Activity 2.6 Ma Off Axis, J. J. Schwartz, Barbara John, Michael Cheadle, P. W. Reiners, A. G. Baines
Cooling History Of Atlantis Bank Oceanic Core Complex: Evidence For Hydrothermal Activity 2.6 Ma Off Axis, J. J. Schwartz, Barbara John, Michael Cheadle, P. W. Reiners, A. G. Baines
Michael Cheadle
We report 26 (U-Th)/He zircon ages from Atlantis Bank, Southwest Indian Ridge, which constrain time scales and rates of lower crustal cooling in ultraslow spreading oceanic crust in this setting. Samples from the detachment fault surface indicate that denuded oceanic crust cooled rapidly (< 1 Ma), yielding cooling rates > 1200 degrees C/Ma, consistent with existing models for the cooling of oceanic crust. (U-Th)/He zircon ages from samples collected along N-S and E-W trending faults scarps record young ages inconsistent with standard cooling models for lower oceanic crust. These samples have a mean (U-Th)/He zircon age 2.6 Ma younger than their corresponding igneous crystallization ages and …
Cooling History Of Atlantis Bank Oceanic Core Complex: Evidence For Hydrothermal Activity 2.6 Ma Off Axis, J. J. Schwartz, Barbara John, Michael Cheadle, P. W. Reiners, A. G. Baines
Cooling History Of Atlantis Bank Oceanic Core Complex: Evidence For Hydrothermal Activity 2.6 Ma Off Axis, J. J. Schwartz, Barbara John, Michael Cheadle, P. W. Reiners, A. G. Baines
Barbara John
We report 26 (U-Th)/He zircon ages from Atlantis Bank, Southwest Indian Ridge, which constrain time scales and rates of lower crustal cooling in ultraslow spreading oceanic crust in this setting. Samples from the detachment fault surface indicate that denuded oceanic crust cooled rapidly (< 1 Ma), yielding cooling rates > 1200 degrees C/Ma, consistent with existing models for the cooling of oceanic crust. (U-Th)/He zircon ages from samples collected along N-S and E-W trending faults scarps record young ages inconsistent with standard cooling models for lower oceanic crust. These samples have a mean (U-Th)/He zircon age 2.6 Ma younger than their corresponding igneous crystallization ages and …
Extensional Folds Associated With Paleogene Detachment Faults In Se Part Of The Salmon Basin, Susanne U. Janecke, J. C. Blankenau
Extensional Folds Associated With Paleogene Detachment Faults In Se Part Of The Salmon Basin, Susanne U. Janecke, J. C. Blankenau
Susanne U. Janecke
No abstract provided.
Field Trip Roadlog For The Bear River Landslide Complex, James P. Mccalpin
Field Trip Roadlog For The Bear River Landslide Complex, James P. Mccalpin
James P. McCalpin
The Bear River Landslide Complex occurs where the unconsolidated sediments of the Bear River Delta have been incised to a depth of 350 to 490 feet (106-150 m) north of Preston, Idaho. The slides are the result of the high pore pressure in confined aquifers in the deltaic sediments. High but variable volumes of groundwater flow and the laterally discontinuous nature of the deltaic sediments result in the varied types of earth movements found within the Landslide Complex. Landslide activity occurs during years of above average precipitation, and has been exacerbated by increased recharge from reservoirs and irrigation canals constructed …
Thermoluminescence (Tl) Dating In Seismic Hazard Evaluations: An Example From The Bonneville Basin, Utah, James P. Mccalpin
Thermoluminescence (Tl) Dating In Seismic Hazard Evaluations: An Example From The Bonneville Basin, Utah, James P. Mccalpin
James P. McCalpin
Thermoluminescence (TL) of minerals is the release of light when grains are heated to 1500 -5000 C. As sediments are buried longer they progressively acquire more TL from accumulated radiation damage from alpha, beta, and gamma rays and cosmic radiation. If the total amount of radiation dose received can be calculated, and the current dose rate measured, then dividing the total dose by the yearly dose rate will yield a TL age. Total doses are calculated by heating the sample until all TL is released, then re-irradiating the sample in the lab with known doses until the natural TL is …