Identification_Information: Citation: Citation_Information: Originator: Kellogg, Karl S. Originator: Bartos, Paul, J. Originator: Williams, Cindy L. Publication_Date: 2002 Title: Geologic map of the Frisco quadrangle, Summit County, Colorado Series_Information: Series_Name: Miscellaneous Field Studies Map Issue_Identification: MF-2340 Publication_Information: Publication_Place: Denver, Colorado Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/mf/2002/mf-2340/ Description: Abstract: New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western Colorado, in support of the USGS Central Region State/USGS Cooperative Geologic Mapping Project, is contributing to a more complete understanding of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing region. The 1:24,000-scale Frisco quadrangle is near the headwaters of the Blue River and straddles features of the Blue River graben (Kellogg, K.S., 1999, Neogene basins of the northern Rio Grande rift—partitioning and asymmetry inherited from Laramide and older uplifts: Tectonophysics, v. 305, p. 141-152.), part of the northernmost reaches of the Rio Grande rift, a major late Oligocene to recent zone of extension that extends from Colorado to Mexico. The Williams Range thrust fault, the western structural margin of the Colorado Front Range, cuts the northeastern corner of the quadrangle. The oldest rocks in the quadrangle underlie the Tenmile Range and include biotite-sillimanite schist and gneiss, amphibolite, and migmatite that are intruded by granite inferred to be part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, Ogden, 1987, Rock units of the Precambrian- basement in Colorado: U.S. Geological Survey Professional Paper 1321-A, 54 p.). The oldest sedimentary unit is the Pennsylvanian Maroon Formation, a sequence of red sandstone, conglomerate, and interbedded shale. The thickest sequence of sedimentary rocks is Cretaceous in age and includes at least 500 m of the Upper Cretaceous Pierre Shale. The sedimentary rocks are intruded by sills and dikes of dacite porphyry sills of Swan Mountain, dated at 44 Ma (Marvin, R.F., Mehnert, H.H., Naeser, C.W., and Zartman, R.E., 1989, U.S. Geological Survey radiometric ages, compilation “C”—Part five—Colorado, Montana, Utah, and Wyoming: Isochron/West, no. 53, p. 14-19. Simmons, E.C., and Hedge, C.E., 1978, Minor-element and Sr-isotope geochemistry of Tertiary stocks, Colorado mineral belt: Contributions to Mineralogy and Petrology, v. 67, p. 379-396.). Surficial deposits include (1) an old, deeply dissected landslide deposit, possibly as old as Tertiary, on the south flank of Tenderfoot Mountain, (2) deeply weathered, very coarse gravel deposits, mostly along Gold Run and underlying Mesa Cortina; the gravels are gold bearing and were mined by hydraulic methods in the 1800's, (3) glacial deposits of both Bull Lake (middle Pleistocene) and Pinedale (late Pleistocene) that were derived from large valley glaciers that flowed down Tenmile and North Tenmile Creeks; the town of Frisco is underlain mostly by Pinedale-age glacial outwash, (4) recent landslide deposits, including one large (about 1 square kilometer) area just downslope from Lilly Pad Lake, west of I-70, and (5)extensive colluvial and alluvial deposits. The latest seismic events appear to be middle Pliestocene in age and are associated with small scarps that cut Bull Lake till but do not cut Pinedale till. Purpose: To update and reinterpret earlier geologic mapping, and to achieve a uniform regional geologic database. Supplemental_Information: Map political location: Summit County, Colorado Compilation scale: 1:24,000 Geology mapped in 1997 and 1998. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2000 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: Irregular. Mapping is continuing in adjacent quadrangles and revisions may be made as required. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -106.125 East_Bounding_Coordinate: -106.0 North_Bounding_Coordinate: 39.612 South_Bounding_Coordinate: 39.50 Keywords: Theme: Theme_Keyword_Thesaurus: AGI Glossary of Geology Theme_Keyword: Geologic map Theme_Keyword: Frisco, Colorado Theme_Keyword: Blue River Theme_Keyword: Blue River graben Theme_Keyword: Williams Range thrust fault Theme_Keyword: Proterozoic rocks Theme_Keyword: Cretaceous rocks Theme_Keyword: Dillon Reservoir Place: Place_Keyword_Thesaurus: none Place_Keyword: USA Place_Keyword: Colorado Place_Keyword: Summit County Stratum: Stratum_Keyword_Thesaurus: none Stratum_Keyword: Maroon Stratum_Keyword: Chinle Stratum_Keyword: Entrada Stratum_Keyword: Morrison Stratum_Keyword: Dakota Stratum_Keyword: Benton Stratum_Keyword: Niobrara Stratum_Keyword: Pierre Access_Constraints: none Use_Constraints: none. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. Browse_Graphic: Browse_Graphic_File_Name: http://pubs.usgs.gov/mf/2002/mf-2340/mf-2340.pdf/ Browse_Graphic_File_Description: graphic representation of map layout; includes correlation, cross sections, list of map units, and index maps Browse_Graphic_File_Type: PDF Data_Set_Credit: A.M. Licamelli, R.G. Kuehn, K.S. Morgan Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Data was entered and checked by the geologist who made the observations. The attributes of this geospatial data set consist of text identifiers and numeric codes that indicate the identity of the geologic unit or type of geologic feature, and determine how each feature is colored or symbolized. To check attribute accuracy, a color check plot was visually compared to the geologist's original compilation. Discrepancies between the digital geospatial dataset and the original analog compilation were corrected as needed. Machine-created listings of unique attribute values were used to identify spelling errors or other inconsistencies, and corrections were made as needed. This map has been thoroughly reviewed for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. Logical_Consistency_Report: Map elements were visually checked by the author for overshoots, undershoots, duplicate features, polygon attributes, and other errors. Automated (ARC/INFO) routines were also used to check the databases for polygon label errors, line or point attribution errors, sliver polygons, dangling arcs, intersection errors, and projection information. The map was reviewed by two other geologists for consistency with basic geologic principles and general conformity to USGS mapping standards. Completeness_Report: Data is complete: no features were eliminated or generalized. Unit properties are described in the text explanation. A digital base map coverage is not included but is available separately. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Lines were primarily mapped by ground investigation and photo-interpretation of 1:24,000-scale color aerial photographs. These lines were digitized from the topographic field sheets and from annotated aerial photographs. Most digitized positions on the map are estimated to have about 20 m horizontal accuracy. Additional point observations were added using positions determined by a Rockwell PLGR-96 GPS unit with horizontal accuracy of about 10 m. There is no elevation data in the database. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Kellogg, Karl Originator: Bartos, Paul Originator: Williams, Cindy Title: Unpublished mapping done in 1997 and 1998 Publication_Date: Unpublished material Type_of_Source_Media: Original mapping compiled on a greenline mylar topographic base map Source_Time_Period_of_Content: Source_Currentness_Reference: Geologic mapping was done in 1997 and 1998 Time_Period_Information: Range_of_Dates/Times: 1997-1998 Source_Citation_Abbreviation: Kellogg and others (2002) Source_Contribution: This data was used to compile the geologic map. Process_Step: Process_Description: The Frisco geologic database was compiled using the GSMCAD public domain program (USGS Open-File Report 96-007; program availible at http://ncgmp.cr.usgs.gov/ncgmp/gsmcad). It was exported to ARC/INFO using the GSMCAD export function to create ARC generate ASCII files and the gsmarc.aml program in ARC was used to convert the ASCII files to ARC coverages and build polygons. The compilation was completed November, 1999. The review and revision was completed April, 2000. Archive files prepared June 2002. Process_Date: 2002 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Polyconic Polyconic: Longitude_of_Central_Meridian: -105.5 Latitude_of_Projection_Origin: 0.0 False_Easting: 0.000 False_Northing: 0.000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 20 Ordinate_Resolution: 20 Planar_Distance_Units: METERS Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The data is supplied in ARC/INFO export and shape file formats. DATABASE STRUCTURE - ARC/INFO ==================================== The database of the map consists of coverages, including corresponding INFO files: friscopoly2 coverage: Contains all contact lines and labelpoints for each polygon. In the coverage's friscopoly2.aat INFO file the CODE item provides a numeric code that specifies the geologic identity and positional quality of each contact line (e.g., fault, approximately located), and the P1 and P2 items are relic cartographic parameters from the GSMCAD compilation program. The friscopoly2.aat CODE values are defined below. In the friscopoly2.pat INFO file the CODE and P2 items are relic cartographic parameters from the GSMCAD program, the P1 item provides a numeric code that specifies the polygon's map unit identity, the TEXT item indicates the map unit label for each polygon, and the SYMBOL item defines the polygon color as chosen from the color524.shd shadeset (included in bundled file archive). The friscopoly2.pat P1 and TEXT items are listed below. friscoline2 coverage: Contains faults, fold axes, and other non-contact lines. Faults that are contacts also appear in the friscopoly2 coverage. In the friscoline2.aat INFO file the CODE item provides a numeric code that specifies the geologic identity and positional quality for each type of line, the P1 and P2 items are relic cartographic parameters from the GSMCAD program, and the TEXT item describes the geologic identity, positional quality, and, in some cases, additional aspects of each line. The friscoline2.aat CODE and TEXT items are listed below. friscopoint2 coverage: Contains points used for cartographically decorating lines, such as "ball-and-bar" fault symbols, and teeth on thrust faults. In the INFO file friscopoint2.pat the CODE item defines a numeric code for each type of point decoration and the P1 and P2 items indicate the orientation (or strike azimuth) and, where appropriate, dip (or plunge) value associated with each point symbol. The friscopoint2.pat CODE items are listed below. Auxiliary files: color524.shd: This shadeset file defines the rgb values of colors assigned to polygons in the friscopoly2 coverage (see SYMBOL item). Readme.doc: Disclaimer and list of included files. Entity_and_Attribute_Detail_Citation: For map unit labels, refer to map text (in pdf browse graphic file) P1 | GEOLOGIC MAP UNIT LABELS 205 | af 207 | dt 148 | Qal 165 | Qs 164 | Qav 163 | Qry 161 | Qr 176 | Qtr 147 | Qf 162 | Qt 101 | Qc 100 | Qac 155 | Qls 152 | Qg 206 | Qop 200 | Qtp 201 | Qtb 204 | Qgo 210 | Qgm 202 | Qgg 175 | Qd 153 | QTls 220 | Tqp 233 | Kpm 232 | Kps 231 | Kpl 240 | Kn 242 | Kb 106 | Kd 104 | Jm 105 | Je 107 | TrPcm 162 | Xu 266 | Xgg 264 | Xgd 259 | Xmg 263 | Xhpg 250 | Xbg 255 | YXp 257 | Yxdi 262 | YXu 265 | Xum DEFINITION OF CODES IN THE DATABASE COVERAGES (CODES AND TEXT LISTED IN THE .AAT AND .PAT FILES) CODE | TEXT (DEFINITION) 1 | contact; certain 2 | contact; approximately located 3 | contact; concealed 11 | fault; certain 12 | fault; approximately located 13 | fault; concealed 21 | normal fault; certain 22 | normal fault; approximately located 23 | normal fault; concealed 31 | thrust fault; certain; upthrown on right side 32 | thrust fault; approximate location; upthrown on right side 33 | thrust fault; concealed; upthrown on right side 41 | reverse fault; certain 42 | reverse fault; approximately located 43 | reverse fault; concealed 51 | syncline axis; certain 52 | syncline axis; concealed 61 | anticline axis; certain 62 | anticline axis; concealed 65 | strike-slip arrows 71 | dike or sill 72 | quartz vein 93 | water boundary 94 | scratch contact 95 | cross-section line 99 | map boundary 200 | plunge arrow 201 | bedding attitude (P1=strike azimuth 90 deg.CCW from dip direction, P2=dip angle) 202 | strike and dip foliation symbol 203 | plunge and bearing (lineation)symbol 204 | anticline arrows(P1=orientation azimuth) 205 | syncline arrows(P1=orientation azimuth) 207 | bar and ball symbol(P1=orientation azimuth) 208 | dip symbol on contact or fault (P1=strike azimuth, P2=dip angle) 209 | left-lateral arrows (P1=orientation azimuth) 210 | right-lateral arrows(P1=orientation azimuth) 213 | strike and dip of joints symbol (P1=strike azimuth 90 deg.CCW from dip direction, P2=dip angle) 217 | fold plunge arrow symbol(P1=orientation azimuth) 219 | strike and dip of overturned beds symbol(P1=strike azimuth 90 deg.CCW from dip direction, P2=dip angle) 220 | strike and dip, approximate (P1=strike azimuth 90 deg.CCW from dip direction, P2=dip angle) 221 | vertical bed symbol(P1=orientation azimuth) 222 | vertical foliation symbol(P1=orientation azimuth) 230 | vertical joint symbol(P1=orientation azimuth) 246 | strike with undetermined dip symbol(P1=strike azimuth 90 deg.CCW from dip direction, P2=dip angle) 251 | strike and dip of foliation symbol(P1=strike azimuth 90 deg.CCW from dip direction, P2=dip angle) 500 | Unit labels text & tag 501 | Hidden unit tags 502 | rock text 510 | ordinary text 701 | Splined text Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: Central Publications Group Address: U.S. Geological Survey Address: MS 902, Box 25046 DFC City: Lakewood State_or_Province: CO Postal_Code: 80225-0046 Contact_Voice_Telephone: 303-236-7431 Distribution_Liability: Although this digital spatial data has been subjected to rigorous review and is substantially complete, it is released on the condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARCE, SHP Format_Version_Number: 7.12 Format_Version_Date: 1997 File_Decompression_Technique: GZIP compressed TAR file (Unix), ZIP archive (Windows) Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/mf/2002/mf-2340/ Fees: none Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: USGS Information Services Address: Box 25286 City: Denver State_or_Province: CO Postal_Code: 80225 Country: United States Contact_Voice_Telephone: 1-888-ASK-USGS Resource_Description: MF-2340 (Map-on-Demand) Distribution_Liability: None Standard_Order_Process: Non-digital_Form: Available as one printed map sheet plus one pamphlet. Order from USGS at the address listed above or see http://rockyweb.cr.usgs.gov/mod/index.html for more ordering information. Fees: For current charges see http//rockyweb.cr.usgs.gov/mod/order.html Metadata_Reference_Information: Metadata_Date: 20020606 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Karl S. Kellogg Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Address: MS 913, Box 25046 DFC City: Lakewood State_or_Province: CO Postal_Code: 80225-0046 Contact_Voice_Telephone: 303-236-1305 Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998