Principal Facts for Gravity Stations in the Vicinity of San Bernardino, Southern California

Online link https://geo-nsdi.er.usgs.gov/metadata/open-file/00-193/metadata.faq.html
Description New gravity measurements in the vicinity of San Bernardino, California were collected to help define the characteristics of the Rialto-Colton fault. The data were processed using standard reduction formulas and parameters. Rock properties such as lithol
Originators Anderson, M. L.; Roberts, C. W.; and Jachens, Robert C.
Publication U.S. Geological Survey Open-File Report 00-193

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Overview of attributes

The data files are in ASCII format.  The gravity data define
point data with information as follows:
STATION NAME (a8):  An alphanumeric combination of up to 8
characters used for station identification;
LAT (f3.0,f6.3):  Latitude in degrees and minutes, to 0.01 minute;
LON (f4.0,f6.3):  Longitude in degrees and minutes, to 0.01 minute;
ELEV (f8.2):  Elevation, to 0.1 ft;
OG (f10.3):  Observed gravity, to 0.01 mGal;
FAA (f9.3):  Free-air anomaly to 0.01 mGal;
SBA (f8.3):  Simple Bouguer anomaly to 0.01 mGal;
ITC (f7.3):  Inner terrain correction for a density of 2.67 g/cm3,
to 0.01 mGal, followed by a letter denoting the extent
of the correction.  "Z" indicates computer terrain correction
from the station out to 166.7 km with inner terrain correction
out to D zone;
TC (f7.3):  Total terrain correction from the station to 166.7
km for a density of 2.67 g/cm3, to 0.01 mGal;
TC CODE (a1):  Letter denoting the extent of the correction,
according to the Hayford-Bowie template (e.g. 'D' means 590 m);
CBA (f8.3):  Complete Bouguer anomaly reduced for a density
of 2.67 g/cm3, to 0.01 mGal;
ISO (f8.3):  Isostatic residual anomaly values assuming an
Airy model for isostatic compensation of topographic loads.
This model assumes a crustal thick ness of 25 km, a topographic
load density of 2.67 g/cm3, and a density contrast across the
base of the model crust of 0.4 g/cm3;
The density and susceptibility data define point data with
information as follows:
STATION NAME (a8):  An alphanumeric combination of up to
8 characters used for station identification;
LAT (f3.0,f6.3):  Latitude in degrees and minutes,
to 0.01 minute;
LON (f4.0,f6.3):  Longitude in degrees and minutes,
to 0.01 minute;
GRAIN DENSITY (f7.2):  in grams per cubic centimeter;
SATURATED BULK DENSITY (f6.2):  in grams per cubic centimeter;
DRY BULK DENSITY (f6.2):  in grams per cubic centimeter;
MAGNETIC SUSCEPTIBILITY (f7.2):  in 10-3 cgs units;
GEOLOGIC MAP UNIT (a10):  An alphanumeric combination of
up to 10 characters for corresponding geologic map unit
when plotted on the 1:24,000 geologic map, see open-file
report for map references;
ROCK TYPE (a32):  description of hand sample.

http://pubs.usgs.gov/of/2000/0193/pdf/of00-193.pdf