Preliminary geologic map emphasizing bedrock formations in Alameda County, California: A digital database

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Description This Open-File report is a digital geologic map database of the Alameda County, California.
Originators Graymer, Russell W.; Jones, D. L.; and Brabb, Earl E.
Publication U.S. Geological Survey Open-File Report 96-252

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Point at which gravity anomaly was measured

Label Definition
STAT Station Name--An alphanumeric combination of up to 8 characters used for station identification
LaD Degree Latitude North
LaM Decimal Minute
LoD Degree Longitude West
LoM Decimal Minute
ELEV Elevation in feet
acc accuracy indicator?
OG Observed gravity, in mGal
FAA Free-air anomaly, in mGal
SBA Simple Bouguer anomaly, in mGal
ITC Inner terrain correction for a density of 2.67 g/cc, in mGal. See Code column for radius of correction.
TTC Total terrain correction from the station to 166.7 km for a density of 2.67 g/cc, in mGal.
Code Letter denoting the zone (radius) of the correction
CBA Complete Bouguer anomaly reduced for a density of 2.67 g/cc, in mGal.
ISO Isostatic residual anomaly,in mGal,assuming an Airy model for isostatic compensation of topographic loads. This model assumes a crustal thickness of 25 km, a topographic load density of 2.67 g/cc, and a density contrast across the base of the model crust of 0.4 g/cc. Isostatic correction would be difference between CBA and ISO values.