Supplemental_Information:
Procedures_Used
Outcrop outlines from several maps at different scales (see
"References Cited" section) were manually copied onto mylar overlays
of 20 paper USGS 7.5-minute topographic series quadrangle maps
that encompass the Denver metropolitan area. These maps were the
Arvada, Box Elder School, Brighton, Commerce City, Coal Creek,
Eastlake, Englewood, Fitzsimons, Fort Logan, Golden, Highlands Ranch,
Indian Hills, Lafayette, Littleton, Louisville, Mile High Lakes,
Morrison, Parker, Piney Creek, and Sable quadrangles. These maps
were converted to ARC/INFO format by digitizing the outlines into
20 corresponding digital geospatial data sets, known as coverages
in ARC/INFO-specific terminology. Each coverage was in the polyconic
projection specific to each quadrangle: the central meridian is
the longitude of the center of the quadrangle, and the latitude of
the origin is the latitude at the base of the quadrangle. Regis-
tration root mean square errors of 0.008 or less were acceptable
for the digitization process. Drafts of these coverages were then
plotted at a scale of 1:24,000, checked against the original mylar
sheets, and corrected for omissions. The coverages were then
projected into a common state plane projection and edgematched.
The northern and eastern areas of each coverage were edgematched
when necessary. The northern edge of a coverage was adjusted to fit
the southern edge of a coverage adjacent to the north; the eastern
edge of a coverage was adjusted to fit the western edge of a coverage
adjacent to the east.
The coverages were appended into a single coverage that was then
cleaned with a dangle tolerance of 12.192 feet and a fuzzy tolerance
of 1.2192 feet. The coverage was built with line topology. Arc
item "CONTOUR" was added to the arc attribute table of the coverage.
The coverage was plotted at 1:50,000 scale, checked against the
mylar overlays, and corrected. Finally, outlines of the study area
were added to the coverage so it could be cleaned and built as a
polygon coverage. Polygon item "OUTCROPFLAG" was added to the
polygon attribute table of the coverage. Two other items, "LPOLY#"
and "RPOLY#," were added to the polygon attribute table as items
redefined from "OUTCROPFLAG." Item "OUTCROPFLAG" could then be
attributed in INFO (see Entity and Attribute Overview for polygon
items, "LPOLY#" and "RPOLY#"):
ENTER COMMAND >SEL ALL_OCSPC3CL1.AAT
1079 RECORD(S) SELECTED
ENTER COMMAND >RELATE 1 ALL_OCSPC3CL1.PAT BY LPOLY#
ENTER COMMAND >RELATE 2 ALL_OCSPC3CL1.PAT BY RPOLY#
ENTER COMMAND >RESEL LPOLY# = 1 OR RPOLY# = 1
883 RECORD(S) SELECTED
ENTER COMMAND >CALC $1OUTCROPFLAG = 1
ENTER COMMAND >CALC $2OUTCROPFLAG = 2
The final coverage is intended to be used as one thematic layer in
maps to be published at a scale of 1:50,000.
Revisions
Rev 1.0, September 1994, original coverage.
Reviews_Applied
July-August 1994: Colleague review of 1:50,000-scale maps that
were generated from the original data set. Manuscript review
included validation of method as outlined in map report and
inspection for positional accuracy.
January-Febuary 1996: Colleague review of original digital data
set and associated metadata. Metadata review included verification
of table and column/item identities and definitions, validation of
the reference data sets and citations, verification of consistency
between log file and documented procedures, and validation of
development method as described in the documentation.
March 1996: Inspection of 1:50,000-scale hardcopy generated from
this data set.
Related_Spatial_and_Tabular_Data_Sets
None.
Other_References_Cited
Robson, S.G., 1996, Geohydrology of the shallow aquifers
in the Denver metropolitan area, Colorado: U.S. Geological
Survey Hydrologic Investigations Atlas HA-736, 5 sheets,
scale 1:50,000.
Bryant, Bruce, Miller, Robert D., and Scott, Glenn R., 1973
[1974], Geologic map of the Indian Hills quadrangle,
Jefferson County, Colorado: U.S. Geological Survey
Geologic Quadrangle Map GQ-1073, scale 1:24,000.
Lindvall, Robert M., 1980, Geologic map of the Sable
quadrangle, Adams and Denver Counties, Colorado: U.S.
Geological Survey Miscellaneous Field Studies Map MF-1180,
scale 1:24,000.
Lindvall, Robert M., 1978, Geologic map of the Fort Logan
quadrangle, Jefferson, Denver, and Arapahoe Counties,
Colorado: U.S. Geological Survey Geologic Quadrangle
Map GQ-1427, scale 1:24,000.
Lindvall, Robert M., 1979, Geologic map of the Arvada
quadrangle, Adams, Denver, and Jefferson Counties, Colorado:
U.S. Geological Survey Geologic Quadrangle Map GQ-1453,
scale 1:24,000.
Lindvall, Robert M., 1980, Geologic map of the Commerce
City quadrangle, Adams and Denver Counties, Colorado:
U.S. Geological Survey Geologic Quadrangle Map GQ-1541,
scale 1:24,000.
Maberry, John O., and Lindvall, Robert M., 1972, Geologic
map of the Parker quadrangle, Arapahoe and Douglas
Counties, Colorado: U.S. Geological Survey Miscellaneous
Investigations Series Map I-770-A, scale 1:24,000.
Maberry, John O., and Lindvall, Robert M., 1977 [1978],
Geologic map of the Highlands Ranch quadrangle, Arapahoe
and Douglas Counties, Colorado: U.S. Geological Survey
Geologic Quadrangle Map GQ-1413, scale 1:24,000.
Machette, Michael N., 1977 [1978], Geologic map of the
Lafayette quadrangle, Adams, Boulder and Jefferson Counties,
Colorado: U.S. Geological Survey Geologic Quadrangle Map
GQ-1392, scale 1:24,000.
Malde, H.E., 1955, Surficial geology of the Louisville
quadrangle, Colorado: U.S. Geological Survey Bulletin
996-E, p. 217-259. Robson, S.G., 1996, Geohydrology of
the shallow aquifers in the Denver metropolitan area,
Colorado: U.G. Geological Survey Hydrologic Investigations
Atlas HA-736, 5 sheets, scale 1:50,000.
Scott, Glen R., 1972, Geologic map of the Morrison quadrangle,
Jefferson County, Colorado: U.S. Geological Survey
Miscellaneous Investigations Series Map I-790-A, scale
1:24,000.
Scott, Glenn R., 1962, Geology of the Littleton quadrangle,
Jefferson, Douglas, and Arapahoe Counties, Colorado:
U.S. Geological Survey Bulletin 1121-L, p. L1-L53,
scale 1:24,000.
Shroba, Ralph R., 1980, Geologic map and physical properties
of the surficial and bedrock units of the Englewood
quadrangle, Denver, Arapahoe, and Adams Counties, Colorado:
U.S. Geological Survey Geologic Quadrangle Map GQ-1524,
scale 1:24,000.
Trimble, Donald E., and Machette, Michael N., 1979, Geologic
map of the Greater Denver area, Front Range urban corridor,
Colorado: U.S. Geological Survey Miscellaneous Investigations
Series I-0856-H, scale 1:100,000.
Trimble, Donald E., and Fitch, Harold R., 1974, Map showing
potential sources of gravel and crushed-rock aggregate in
the Greater Denver area, Front Range urban corridor, Colorado:
U.S. Geological Survey Miscellaneous Investigations Series
Map I-856-A, 1:100,000.
Van Horn, Richard, 1972, Surficial and bedrock geologic map
of the Golden quadrangle, Jefferson County, Colorado:
U.S. Geological Survey Miscellaneous Investigations Series
I-0761-A, scale 1:24,000.
Wells, John D., 1963, Preliminary geologic map of the Eldorado
Springs quadrangle, Boulder and Jefferson Counties, Colorado:
U.S. Geological Survey Miscellaneous Investigations Series
I-0383, scale 1:24,000.
Notes
Char, Stephen J., Sieverling, Jennifer B., and Miller, L. Lee,
1996, Digital geospatial data sets used in the study of
geohydrology of the shallow aquifers in the Denver metro-
politan area, Colorado: a)Bedrock outcrop, b)Unconsolidated-
sediment thickness, c)Water-table altitude, d)Bedrock-
surface altitude, e)Depth to water, and f)Saturated-zone
thickness: U.S. Geological Survey Open-File Report 96-659.
Any use of trade, product, or firm names is for descriptive purposes
only and does not imply endorsement by the U.S. Government.
Although this metadata file is designed to conform to the Federal
Geographic Data Committee Spatial Metadata Content Standard, these
data and this metadata file were developed using ARC/INFO software;
therefore, this file includes ARC/INFO-specific terminology.