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Preliminary Geologic Map of the Topanga 7.5' Quadrangle, Southern California: A Digital Database

Compiled by R.F. Yerkes and R.H. Campbell

1997

Abstract

This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File Report. This digital map database is compiled from previously published sources combined with some new mapping and modifications in nomenclature. The geologic map database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U. S. Geological Survey. For detailed descriptions of the units, their stratigraphic relations and sources of geologic mapping consult Yerkes and Campbell (1994). More specific information about the units may be available in the original sources. The content and character of the database and methods of obtaining it are described herein. The geologic map database itself, consisting of three ARC coverages and one base layer, can be obtained over the Internet or by magnetic tape copy as described below. The processes of extracting the geologic map database from the tar file, and importing the ARC export coverages (procedure described herein), will result in the creation of an ARC workspace (directory) called 'topnga.'

README file: topnga.txt Unformatted documentation file describing content and formats of this publication (20 kB ).

README file as PDF file: topnga.pdf (111 kB ).

Download all the geologic database layers and supporting materials topnga.tar.gz in ARC/INFO 7.x ASCII EXPORT format, and all of the documentation files, packaged in a single UNIX tar file, compressed with gzip. Includes all the geologic map database layers listed below (21 MB compressed download size, 86 MB when uncompressed).

Geology - tp-geol.e00.gz Faults, contacts and geologic units (504 kb compressed download size, 2 MB when uncompressed).

Structure - tp-strc.e00.gz Attitudes and fold axes (64 kB compressed download size, 784 kB when uncompressed).

Fossils - tp-foss.e00.gz Fossil localities (4 kB compressed download size, 22 kB when uncompressed).

Composite base map - tp-topo.e00.gz Composite quadrangle base map layer in vector format (19.2 MB compressed download size, 82.4 MB when uncompressed).

• This report is available only on the Web.

For additional information:
Contact Information, Western Region Geology and Geophysics Science Center—Menlo Park
U.S. Geological Survey
345 Middlefield Road, MS-973
Menlo Park, CA 94025-3591
http://geomaps.wr.usgs.gov/

Suggested citation:

R.F. Yerkes, R.F., and Campbell, R.H., compilers, 1997, Preliminary geologic map of the Topanga 7.5' quadrangle, southern California; a digital database: U.S. Geological Survey Open-File Report 95–91, available at https://pubs.usgs.gov/of/1995/of95-091/.

This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Last modified April 17, 2012
First posted June 12, 1997