Open Access. Powered by Scholars. Published by Universities.®

Tectonics and Structure Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Tectonics and Structure

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod)Borehole, Central California, S. D. Springer, J. P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke Jan 2009

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod)Borehole, Central California, S. D. Springer, J. P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke

Susanne U. Janecke

http://lithosphere.geoscienceworld.org/content/1/4/206 The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural …


Geodynamics Of Terrane Accretion Within Southern Alaska, Benjamin Patrick Hooks Jan 2009

Geodynamics Of Terrane Accretion Within Southern Alaska, Benjamin Patrick Hooks

Electronic Theses and Dissertations

The subduction and accretion of an exotic terrane at the southern margin of Alaska is driving uplift of the St. Elias and Alaska Ranges, and is responsible for some of the largest strain releases in history. Here are presented results from numerical models conditioned by geological observations that reproduce the tectonic landscape, deformation, and strain patterns at macro- (1000-km) and meso- (<100 >km) scales. These models utilize completely coupled thermal and mechanical solutions that account for the development of heterogeneities to both the thermal and rheological structure of the lithosphere. Perturbation to the thermal structure related to flattening of the …