Lines were primarily positioned by photointerpretation of aerial photographs by using a PG-2 photogrammetric plotter that rectified the position and transferred it to a basemap. Lines were digitized from the basemap by using a digitizer tablet having a resolution of 0.001 inch. Additional lines and point observations were added in the field by means of positions determined by a PLGR-95 GPS unit having accuracy of about 10 meters. Most positions on the map are estimated to be accurate closer than 30 m horizontally.
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). (Adobe Acrobat 4.0 viewing software is free and can be downloaded at the following URL: <http://www.adobe.com/prodindex/acrobat/readstep.html>) 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). (Adobe Acrobat 4.0 viewing software is free and can be downloaded at the following URL: <http://www.adobe.com/prodindex/acrobat/readstep.html>) 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. Can be displayed using the Adobe Acrobat viewing software (version 4.0).
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