From the abstract: Geologic observations from the Resting Spring and Nopah Ranges (California, USA) together with a synthesis of regional data indicate that previous reconstructions of the Death Valley extensional terrane need to be revised because they do not account for three-dimensional, pre-extensional structures that complicate structural markers used in these reconstructions. This conclusion arises from detailed mapping that indicates structural overprinting of early northeast-trending fold-thrust systems of the Sevier orogenic belt by younger northwest-trending structures. The Resting Spring-Nopah-Spring Mountains restoration provides a template for future restorations. We emphasize that the three-dimensional pre-extensional geometry, together with other markers like Mesozoic magmatic belts and older sedimentary facies trends, provides an opportunity for using modern visualization and database systems to develop high-precision reconstructions using the abundance of crosscutting markers. Thus, although this study, along with other recent studies, indicates that previous reconstructions are not workable, future studies that include the full three-dimensional data could lead to a nearly unique solution to the pre-extensional paleogeography.
Tsunami-generated sediment wave channels at Lake Tahoe, California-Nevada, USA
James G. Moore et al., U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA. Published online 25 June 2014; http://dx.doi.org/10.1130/GES01025.1.
A detailed 1999 USGS sonar map of Lake Tahoe first revealed a giant landslide from the west wall of the lake basin that crossed the lake. The 2.5 cubic mile landslide is the second largest on the continent in the last 2 million years, exceeded only in size by a landslide on the north side o
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Geological Society of America