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Geology topics

E. H. Brown

Publications and source records attributed to E. H. Brown.

6 recordsLinked to original sources

Correlation of early Cretaceous blueschists in Washington, Oregon and northern California

The protolith and metamorphic histories of Early Cretaceous blueschists that occur in Washington, Oregon, and California are remarkably similar. These blueschists are the Shuksan metamorphic suite of northwestern Washington, the Condrey Mountain schist of northern California and southern Oregon, and the Pickett Peak terrane of northern California and southwestern Oregon. We suggest that these bodies were coextensive during their formation. Dispersion of the blueschists occurred in Late Cretaceous time by lateral translation of up to 900 km along the continental margin in response to oblique plate convergence.

California, Oregon, Washington

Database for the geologic map of the Mount Baker 30-minute by 60-minute quadrangle, Washington (I-2660)

This digital map database has been prepared by R.W. Tabor from the published Geologic map of the Mount Baker 30- by 60-Minute Quadrangle, Washington. Together with the accompanying text files as PDF, it provides information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The authors mapped most of the geology at 1:100,000. The Quaternary contacts and structural data have been much simplified for the 1:100,000-scale map and database. The spatial resolution (scale) of the database is 1:100,000 or smaller. This database depicts the distribution of geologic materials and structures at a regional (1:100,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes.

Washington