Geologic Map of the Silt Quadrangle, Garfield County, Colorado

Online link https://geo-nsdi.er.usgs.gov/metadata/map-mf/2331/metadata.faq.html
Description New 1:24,000-scale geologic mapping in the Silt 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of the stratigraphy, structure, and geologic hazards in the area of t
Originators Shroba, Ralph R. and Scott, Robert B.
Publication U.S. Geological Survey Miscellaneous Field Studies Map MF-2331

Related topics

States or counties

Overview of attributes


The data are supplied in ARC/INFO export format.
DATABASE STRUCTURE - ARC/INFO ====================================
The database of the map consists of three coverages (root name = silt), including corresponding info files:
This GIS database includes related look-up tables, which store detailed attribute information.  Arc/Info relates for each coverage are saved in a file named <covername>.rel.  Use the RELATE command with the restore argument at the arc prompt to make the relates active.  Alternatively, in Arctools, use the Relate environment:  open dialog in the Manage - Relates flyout menu under the Arctools menu to make the relates active.
siltpoly coverage:  contains all contact lines and labelpoints for each geologic polygon; also contains lines that are limit of overturned strata.  In the denvpoly.pat INFO file the LABEL item indicates the rock unit label (abbreviation) used to label the unit on the map.  The DESC item contains the formal or informal unit name.  The SOURCE item contains the numeric code used to identify the data source for the rock unit.  The SYMBOL item contains the shadeset symbol number used by ArcInfo to plot a filled/shaded polygon.  The symbol numbers in this coverage refer to the color524.shd shadeset.
In the coverage's siltpoly.aat INFO file the NAME item contains the name given to the structural feature.  The SOURCE item contains the numeric code used to identify the data source for the structural feature.  The SYMBOL item contains the lineset symbol number used by ArcInfo to plot a line.  The symbol numbers in this coverage refer to the geol_sfo.lin lineset.
In the coverage's siltpoly.ref INFO file the SOURCE item lists the numeric code used to identify the data source.  The scale item lists the scale of the source map.  (This value is the denominator of the proportional fraction that identifies the scale of the map that was digitized or scanned to produce the digital map.)  The AUTHORS item lists the author(s) or compiler(s) of source map entered as last name, first name or initial, and middle initial.  The YEAR item lists the source (map) publication date.  The REFERENCE item lists the remainder of the reference in USGS reference format.
The INFO structure of these files is listed below:
>SILTPOLY.AAT
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  FNODE#                 4     5     B      -
>    5  TNODE#                 4     5     B      -
>    9  LPOLY#                 4     5     B      -
>   13  RPOLY#                 4     5     B      -
>   17  LENGTH                 8    18     F      5
>   25  SILTPOLY#              4     5     B      -
>   29  SILTPOLY-ID            4     5     B      -
>   33  LINECODE               3     3     I      -
>   36  NAME                  30    30     C      -
>   66  SOURCE                 4     4     I      -
>   70  SYMBOL                 3     3     I      -
>SILTPOLY.PAT
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  AREA                   8    18     F      5
>    9  PERIMETER              8    18     F      5
>   17  SILTPOLY#              4     5     B      -
>   21  SILTPOLY-ID            4     5     B      -
>   25  SOURCE                 4     4     I      -
>   29  LABEL                 10    10     C      -
>   39  DESC                 100   100     C      -
>  139  SYMBOL                 3     3     I      -
>SILTPOLY.CON
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  LINECODE               3     3     I      -
>    4  SYMBOL                 3     3     I      -
>    7  TYPE                  10    10     C      -
>   17  MODIFIER              20    20     C      -
>   37  CERTAINTY             15    15     C      -
>   52  DESC                 100   100     C      -
>SILTPOLY.REF
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  SOURCE                 4     4     I      -
>    5  SCALE                  8     8     I      -
>   13  AUTHORS              200   200     C      -
>  213  YEAR                   4     4     I      -
>  217  REFERENCE            250   250     C      -
siltline coverage: contains cross-section lines and a synclinal fold axis line.  In the siltline.aat INFO file the NAME item indicates the name given to the structural feature.  The SOURCE item contains the numeric code used to identify the data source for the structural feature.  The DESC item contains the written description or explanation of the contact, boundary, or structural feature.  The SYMBOL item contains the lineset symbol number used by ArcInfo to plot a line.  The symbol numbers in this coverage refer to the geol_sfo.lin lineset.
In the coverage's siltline.ref INFO file the SOURCE item lists the numeric code used to identify the data source.  The scale item lists the scale of the source map.  (This value is the denominator of the proportional fraction that identifies the scale of the map that was digitized or scanned to produce the digital map.)  The AUTHORS item lists the author(s) or compiler(s) of source map entered as last name, first name or initial, and middle initial.  The YEAR item lists the source (map) publication date.  The REFERENCE item lists the remainder of the reference in USGS reference format.
The INFO structure of these files is listed below:
>SILTLINE.AAT
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  FNODE#                 4     5     B      -
>    5  TNODE#                 4     5     B      -
>    9  LPOLY#                 4     5     B      -
>   13  RPOLY#                 4     5     B      -
>   17  LENGTH                 8    18     F      5
>   25  SILTLINE#              4     5     B      -
>   29  SILTLINE-ID            4     5     B      -
>   33  LINECODE               3     3     I      -
>   36  NAME                  30    30     C      -
>   66  SOURCE                 4     4     I      -
>   70  DESC                 100   100     C      -
>  170  SYMBOL                 3     3     I      -
>SILTLINE.CON
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  LINECODE               3     3     I      -
>    4  SYMBOL                 3     3     I      -
>    7  TYPE                  10    10     C      -
>   17  MODIFIER              20    20     C      -
>   37  CERTAINTY             15    15     C      -
>   52  DESC                 100   100     C      -
>SILTLINE.STR
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  LINECODE               3     3     I      -
>    4  SYMBOL                 3     3     I      -
>    7  TYPE                  10    10     C      -
>   17  HORIZONTAL            20    20     C      -
>   37  VERTICAL              20    20     C      -
>   57  FOLD                  15    15     C      -
>   72  PLUNGE                15    15     C      -
>   87  ACCURACY              15    15     C      -
>  102  CERTAINTY             15    15     C      -
>  117  DESC                 100   100     C      -
>SILTLINE.REF
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  SOURCE                 4     4     I      -
>    5  SCALE                  8     8     I      -
>   13  AUTHORS              200   200     C      -
>  213  YEAR                   4     4     I      -
>  217  REFERENCE            250   250     C      -
siltpnt coverage:  Contains points recording site-specific observations and measurements, such as strike and dip of bedding. In the siltpnt.pat INFO file the PTTYPE item lists the type of point symbol, e.g., strike and of inclined bedding.  The MARKER item lists the markerset used for a particular PTTYPE.  MARKER value 1 = GEOSCAMP2.MRK, 2 = OILGAS.MRK, 3 = USGS.MRK.  OILGAS.MRK and USGS.MRK are standard ArcInfo markersets. The SYMBOLCD item lists the marker symbol used by ArcInfo to identify the type of structural map symbol.  Symbol numbers refer to symbols in the 3 markersets listed above.  The STRIKE item contains the strike of bedding.  Strike is an azimuthal angle (measured in degrees from 0 to 360 in a clockwise direction from North).  The DIP item contains the dip of bedding.  This value is an angle measured (in degrees 0 to 90) down from the horizontal; thus a horizontal dip is 0 degrees and a vertical dip is 90 degrees.  The CALCANG item contains an interim value used to calculate SYM$ANGLE.  The SYM$ANGLE item is the angle used to mathematically rotate the map point symbol to its proper orientation on the map.  This item was set equal to the pseudoitem '$ANGLE' (calc SYM$ANGLE = $ANGLE).  The SOURCE item lists the numeric code used to identify the data source.
In the coverage's siltpnt.ref INFO file the SOURCE item lists the numeric code used to identify the data source.  The scale item lists the scale of the source map.  (This value is the denominator of the proportional fraction that identifies the scale of the map that was digitized or scanned to produce the digital map.)  The AUTHORS item lists the author(s) or compiler(s) of source map entered as last name, first name or initial, and middle initial.  The YEAR item lists the source (map) publication date.  The REFERENCE item lists the remainder of the reference in USGS reference format.
The INFO structure of these files is listed below:
>SILTPNT.PAT
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  AREA                   8    18     F      5
>    9  PERIMETER              8    18     F      5
>   17  SILTPNT#               4     5     B      -
>   21  SILTPNT-ID             4     5     B      -
>   25  PTTYPE                80    80     C      -
>  105  SYMBOLCD               3     3     I      -
>  108  STRIKE                 3     3     I      -
>  111  DIP                    3     3     I      -
>  114  CALCANG                4     4     I      -
>  118  SYM$ANGLE              4     4     I      -
>  122  MARKER                 3     3     I      -
>  125  SOURCE                 4     4     I      -
>SILTPNT.REF
>COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
>    1  SOURCE                 4     4     I      -
>    5  SCALE                  8     8     I      -
>   13  AUTHORS              200   200     C      -
>  213  YEAR                   4     4     I      -
>  217  REFERENCE            250   250     C      -
Auxiliary files:
color524.shd:  This shadeset file defines the rgb values of colors assigned to polygons in the siltpoly coverage (see SYMBOL item).
geol_sfo.lin:  This lineset file defines geologic line types in the geologically themed coverages.
geoscamp2.mrk:  This markerset file defines the geologic markers in the geologically themed coverages.
mf-2331_screen.pdf:  A screen optimized file for viewing and printing a graphics version of the map and accessory elements using Adobe Acrobat viewing software (version 4.0).  Accessory map elements displayed in this graphics file are: (1) geologic cross section A-A", (2) geologic cross section B-B', (3) correlation of map units diagram, (4) list of map unit symbols and names, and (5) explanation of map symbols.
mf-2331_print.pdf:  A print optimized file for viewing and printing a graphics version of the map and accessory elements using Adobe Acrobat viewing software (version 4.0).  Accessory map elements displayed in this graphics file are: (1) geologic cross section A-A", (2) geologic cross section B-B', (3) correlation of map units diagram, (4) list of map unit symbols and names, and (5) explanation of map symbols.
mf-2331_pamphlet.pdf:  A detailed textual description of geologic map units and a brief discussion of deposits, structure, and geologic history of the map area.
>Database root name: silt
>Label	            Desc
>af	      Artificial fill (latest Holocene)
>Qfp	      Flood-plain and stream-channel deposits (Holocene and late Pleistocene)
>Qty	      Younger terrace alluvium (late Pleistocene)
>Qtm	      Intermediate terrace alluvium (late Pleistocene)
>Qto	      Older terrace alluvium (late middle Pleistocene)
>Qba	      Basaltic alluvium (late middle Pleistocene)
>Qg	      Gravelly alluvium (late and middle Pleistocene)
>Qtt	      Oldest terrace alluvium (middle Pleistocene)
>Qfy	      Younger fan-alluvium and debris-flow deposits (Holocene and latest
>            Pleistocene)
>Qac	      Alluvium and colluvium, undivided (Holocene and late Pleistocene)
>Qp	      Pediment deposits (middle Pleistocene)
>Qc         Colluvium, undivided (Holocene to middle? Pleistocene)
>Qsw	      Sheetwash deposits (Holocene and late Pleistocene)
>Qsw/Qlo    Sheetwash deposits over loess
>Qls	      Landslide deposits (Holocene to middle? Pleistocene)
>Qd	      Debris-flow deposits (Holocene? to middle? Pleistocene
>Qdo	      Older debris-flow deposits (early? Pleistocene)
>Qlo	      Loess (late and middle? Pleistocene)
>Qlo/Qty    Loess over younger terrace alluvium
>Qlo/Qtm    Loess over intermediate terrace alluvium
>Qlo/Qto    Loess over older terrace alluvium
>Qlo/Qd     Loess over debris-flow deposits
>Qlo/Qtt    Loess over oldest terrace alluvium
>Qlo/Qp     Loess over pediment deposits
>Qlo/Qtt/Qp Loess over oldest terrace alluvium over pediment deposits
>Tw         Wasatch Formation (in cross section only) (Eocene to Paleocene)
>Tws	      Shire Member of Wasatch Formation (Eocene)
>Twss	      Sandstone unit of Shire Member of Wasatch Formation
>Twm 	      Molina Member of Wasatch Formation (Eocene)
>Twa	      Atwell Gulch Member of Wasatch Formation (in cross section only)
>            (Paleocene)
>Twav	      Volcaniclastic-rich unit of Atwell Gulch Member of Wasatch Formation
>Twal	      Lower unit of Atwell Gulch Member of Wasatch Formation
>Kmv	      Mesaverde Group (in cross section only) (Upper Cretaceous)
>Kwf	      Williams Fork Formation of Mesaverde Group
>Kwfu	      Upper unnamed sandstone unit of Williams Fork Formation of Mesaverde Group
>Kwfl	      Lower unnamed sandstone unit of Williams Fork Formation of Mesaverde Group
>Ki	      Iles Formation of Mesaverde Group
>Kir	      Rollins Sandstone Member of Iles Formation of Mesaverde Group
>Kicc	      Cozzette Sandstone and Corcoran Sandstone Members, undivided, of the Iles
>            Formation of Mesaverde Group
>Kmvb	      Baked zone in the Mesaverde Group
>Kmu	      Mancos Shale, Upper member (Upper Cretaceous)
>DEFINITION OF LINECODES IN THE COVERAGES (LINECODES AND DESC IN THE .CON AND .STR
>FEATURES IN THE DATABASE-------------------------
>LINECODE |   DESC
>    1    | contact; certain
>    2    | contact; approximately located
>   41    | water boundary
>   81    | map boundary (lines of latitude or longitude)
>   88    | limit of overturned strata
>   98    | cross-section line
>  413    | fold axis; syncline; certain

http://pubs.usgs.gov/mf/2001/mf-2331/mf-2331pam.pdf