Identification_Information: Citation: Citation_Information: Originator: Scott, Robert B. Originator: Carrara, Paul E. Originator: Hood, William C. Originator: Murray, Kyle E. Publication_Date: 2002 Title: Geologic map of the Grand Junction quadrangle, Mesa County, Colorado Edition: 1.0 Geospatial_Data_Presentation_Form: Map Series_Information: Series_Name: Miscellaneous Field Studies Issue_Identification: MF-2363 Publication_Information: Publication_Place: Denver, CO Publisher: U.S. Geological Survey Online_Linkage: http://geology.cr.usgs.gov/pub/mf-maps/mf-2363/ Description: Abstract: This 1:24,000-scale geologic map of the Grand Junction 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 the junction of the Colorado River and the Gunnison River. Bedrock strata include the Upper Cretaceous Mancos Shale through the Lower Jurassic Wingate Sandstone units. Below the Mancos Shale, which floors the Grand Valley, the Upper and Lower(?)Cretaceous Dakota Formation and the Lower Cretaceous Burro Canyon Formation hold up much of the resistant northeast- dipping monocline along the northeast side of the Uncompahgre uplift. The impressive sequence of Jurassic strata below include the Brushy Basin, Salt Wash, and Tidwell Members of the Upper Jurassic Morrison Formation, the Middle Jurassic Wanakah Formation and informal "board beds" unit and Slick Rock Member of the Entrada Formation, and the Lower Jurassic Kayenta Formation and Wingate Sandstone. The Upper Triassic Chinle Formation and Early Proterozoic meta-igneous gneiss and migmatitic meta- sedimentary rocks, which are exposed in the Colorado National Monument quadrangle to the west, do not crop out here. The monoclinal dip slope of the northeastern margin of the Uncompahgre uplift is apparently a Laramide structural feature. Unlike the southwest-dipping, high-angle reverse faults in the Proterozoic basement and s-shaped fault- propagation folds in the overlying strata found in the Colorado National Monument 7.5' quadrangle along the front of the uplift to the west, the monocline in the map area is unbroken except at two localities. One locality displays a small asymmetrical graben that drops strata to the southwest. This faulted character of the structure dies out to the northwest into an asymmetric fault-propagation fold that also drops strata to the southwest. Probably both parts of this structure are underlain by a northeast-dipping high-angle reverse fault. The other locality displays a second similar asymmetric fold. No evidence of post-Laramide tilting or uplift exists here, but the antecedent Unaweep Canyon, only 30 km to the south-southwest of the map area, provides clear evidence of Late Cenozoic, if not Pleistocene, uplift. The major geologic hazards in the area include large landslides associated with the dip-slope-underlain, smectite-rich Brushy Basin Member of the Morrison Formation and overlying Dakota and Burro Canyon Formations. Active landslides affect the southern bank of the Colorado River where undercutting by the river and smectitic clays in the Mancos trigger landslides. The Wanakah, Morrison, and Dakota Formations and the Mancos Shale create a significant hazard to houses and other structures by containing expansive smectitic clay. In addition to seasonal spring floods associated with the Colorado and Gunnison Rivers, a serious flash flood hazard associated with sudden summer thunderstorms threatens the intermittent washes that drain the dip slope of the monocline. Purpose: To update and reinterpret earlier geologic mapping, and provide sufficient geologic information for land-use decisions for private land and for areas managed by the Bureau of Land Management and the National Park Service. Use of these data at scales greater than 1:24,000 would be inappropriate because mapping was performed at that scale. Supplemental_Information: Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ARC/INFO format, this metadata file may include some ARC/INFO-specific terminology. >Geospatial data files of this data set: > gj24k: geology polygons, contacts, faults > gjpnt: point data representing bedding attitudes > gjline: line representing location of the cross section, > and fold axes > >Symbolsets used for plotting in ArcInfo: > wpgcmykg.shd: shadeset > geol_sfo.lin: lineset > geoscamp1.mrk: markerset Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2002 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -108.625 East_Bounding_Coordinate: -108.500 North_Bounding_Coordinate: 39.125 South_Bounding_Coordinate: 39.000 Keywords: Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: geologic map Theme_Keyword: landslides Theme_Keyword: expansive clays Place: Place_Keyword_Thesaurus: none Place_Keyword: Grand Junction Place_Keyword: Mesa County Place_Keyword: Colorado Place_Keyword: Colorado River Place_Keyword: Gunnison River Place_Keyword: USA Temporal: Temporal_Keyword_Thesaurus: none Temporal_Keyword: Quaternary Temporal_Keyword: Cretaceous-Jurassic Temporal_Keyword: Laramide Access_Constraints: none Use_Constraints: none. Acknowledgment of the U.S. Geological Survey would be appropriate in products derived from these data. Native_Data_Set_Environment: SunOS, 5.7, sun4d UNIX ARC/INFO version 7.2.1 Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Robert B. Scott Contact_Organization: U.S. Geological Survey Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: MS 913 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303-236-1230 Contact_Facsimile_Telephone: 303-236-5690 Contact_Electronic_Mail_Address: rbscott@usgs.gov Data_Set_Credit: Geology south of the Colorado River mapped by Robert B. Scott and William C. Hood in 1998 and 1999. Geology north of the Gunnison River mapped by Paul E. Carrara in 1999. Digital compilation by Kyle E. Murray in 2000. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Attributes were checked by manually comparing hard copy plots of the digital data with the source materials. Authors and USGS map editors performed separate reviews. The attributes of this geospatial dataset 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. Logical_Consistency_Report: The neatline bounding the map area was mathematically generated in latitudinal and longitudinal coordinates and projected to polyconic projection for capturing of geologic data. ARC/INFO software was used to digitize contacts and structural features that form the perimeters of geologic map polygons. Polygons intersecting the neatline were closed along the border. Segments making up the outer and inner boundaries of a polygon tie end-to-end to completely enclose the area. Line segments are a set of sequentially numbered coordinate pairs. No duplicate features or duplicate points exist in a data string. Intersecting lines are separated into individual line segments at the point of intersection. All nodes are represented by a single coordinate pair which indicates the beginning or end of a line segment. Completeness_Report: Data are complete: no features that could be accurately represented at the compilation scale of 1:24,000 were eliminated or generalized. The smallest area represented is approximately 600 square meters. All geospatial database elements are attributed. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Accuracy of 95% of the horizontal coordinates are within 12 meters on the ground or 1/50th inch on the map by transfer of geologic data on aerial photographs to a stable mylar base using PG-2 photogrammetric plotters. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Robert B. Scott, Paul E. Carrara, William C. Hood Publication_Date: 1999 Title: field notes Geospatial_Data_Presentation_Form: map Source_Scale_Denominator: 24000 Type_of_Source_Media: mylar Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1998 and 1999 Source_Currentness_Reference: Data collection date Source_Citation_Abbreviation: USGS Source_Contribution: conducted field mapping Process_Step: Process_Description: The original map data were manually transferred to stable mylar overlays registered to a stable-base USGS 7.5 minute topographic map by use of optical corrections of PG-2 photogrammetric plotters. Process_Date: 1999 and 2000 Process_Step: Process_Description: Mylar overlays were scanned at 300 dots per inch. Process_Date: 2000 Process_Step: Process_Description: Scanned image was registered to gj24k coverage and rectified with ARC/INFO software. Process_Date: 2000 Process_Step: Process_Description: Linework and symbology were digitized from registered and rectified mylar image using ARC/INFO software. Topology was built after digitizing was completed. Process_Date: 2000 Process_Step: Process_Description: Arcs, polygons, and points were attributed using ARC/INFO software. Process_Date: 2000 Process_Step: Process_Description: Plots were generated and checked versus the original data. Appropriate changes were made to the ARC/INFO GIS database. Process_Date: 2000 Process_Step: Process_Description: First draft of metadata created by Kyle E. Murray using FGDCMETA.AML ver. 1.32 01/11/99 on ARC/INFO data set /data9/kmurray2/grandjunc/gj24k Process_Date: 20000811 Process_Step: Process_Description: Geologic map review performed by U.S. Geological Survey geologists Scott Lundstrom and Ric Page. Process_Date: 2000 Process_Step: Process_Description: Geologic name review performed by U.S. Geological Survey Central Publications Group (Tom Judkins). Process_Date: 2000 Process_Step: Process_Description: Revisions made to geologic map and database as suggested by reviewers. Process_Date: 2000 Process_Step: Process_Description: Associated GIS files and text reviewed by USGS reviewers: R. Randall Schumann and Alex J. Donatich Process_Date: 2000-2001 Process_Step: Process_Description: Revisions made to associated files by Robert B. Scott and Kyle E. Murray Process_Date: 2001 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 599 SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: String Point_and_Vector_Object_Count: 1460 SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains Point_and_Vector_Object_Count: 600 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Polyconic Polyconic: Longitude_of_Central_Meridian: -108.5625 Latitude_of_Projection_Origin: 39 False_Easting: 0.00000 False_Northing: 0.00000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 10 Ordinate_Resolution: 10 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: > >--------------------------------------------------------------- >COVERAGE NAME: gj24k >--------------------------------------------------------------- > >USER-DEFINED ITEMS IN GJ24K.PAT: >------------------------------------ > >ATTRIBUTE NAME: UNIT >DATABASE ITEM STRUCTURE: 4,4,I,0 >DESCRIPTION: unique numeric identifier for each geologic unit >ITEM VALUES FOR 'UNIT': >integer value in the range 1 - 38 > >ATTRIBUTE NAME: LABEL >DATABASE ITEM STRUCTURE: 10,10,C,0 >DESCRIPTION: geologic unit label >ITEM VALUES FOR 'LABEL': >(see table below) > >ATTRIBUTE NAME: DESC >DATABASE ITEM STRUCTURE: 100,100,C,0 >DESCRIPTION: text description of geologic unit >ITEM VALUES FOR 'DESC': >(see table below) > >ATTRIBUTE NAME: SYMBOL >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: shade symbol used to color geology polygons >ITEM VALUES FOR 'SYMBOL': >integer value in the range 12 - 930 > >RELATIONSHIP OF ITEMS 'UNIT', 'LABEL', 'SYMBOL', and 'DESC': >UNIT LABEL SYMBOL DESC > 1 af 20 Artificial fill > 32 Jeb 330 Board beds unit of the Entrada Formation > 33 Jes 591 Slickrock Member of the Entrada Formation > 34 Jk 530 Kayenta Formation > 28 Jmb 580 Brushy Basin Member of the Morrison Formation > 38 Jmb 580 Bentonite quarry located in Jmb > 29 Jms 693 Salt Wash Member of the Morrison Formation > 30 Jmt 560 Tidwell Member of the Morrison Formation > 31 Jw 890 Wanakah Formation > 35 Jwg 785 Wingate Sandstone > 27 Kb 880 Burro Canyon Formation > 26 Kd 590 Dakota Formation > 25 Km 480 Mancos Shale > 4 Qa 60 Alluvium deposited by tributary streams > 15 Qac 271 Alluvium and colluvium, undivided > 2 Qalc1 40 Youngest alluvium deposited by the Colorado River > 36 Qalc1 40 Gravel pit > 5 Qalc2 80 Oldest alluvium deposited by the Colorado River > 3 Qalg 375 Youngest alluvium deposited by the Gunnison River > 17 Qaso 393 Old alluvial-slope deposit > 23 Qc 30 Colluvium > 14 Qfy 51 Young fan-alluvium and debris-flow deposits > 18 Qlg 484 Local gravel deposits > 19 Qlg/Qt30 284 Local gravel deposits over terrace alluvium 30 of the Colorado River > 24 Qlso 190 Older landslide deposits > 22 Qlsy 899 Younger landslide deposits > 16 Qpwf 12 Pediment deposit of Walker Field > 20 Qse 151 Eolian sand and sheetwash deposits > 21 Qse/Qt30 163 Eolian sand and sheetwash deposits over terrace alluvium 30 of the Colorado River > 12 Qt100 42 Terrace alluvium 100 of the Colorado River > 13 Qt170 74 Terrace alluvium 170 of the Colorado River > 8 Qt30 70 Terrace alluvium 30 of the Colorado River > 9 Qt60c 93 Terrace alluvium 60 of the Colorado River > 10 Qt60g 194 Terrace alluvium 60 of the Gunnison River > 11 Qtc/Qtg 647 Terrace alluvium of the Colorado River over terrace alluvium of the Gunnison River > 7 Qtgu 696 Terrace alluvium of the Gunnison River, undivided > 6 Qvf 33 Valley-fill deposits > 37 river 930 river water > >USER-DEFINED ITEMS IN GJ24K.AAT: >------------------------------------ > >ATTRIBUTE NAME: LINECODE >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: unique numeric identifier for linear feature type >ITEM VALUES FOR 'LINECODE': >integer value in the range 1 - 106 > >ATTRIBUTE NAME: SYMBOL >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: line symbol to be used to draw line entities >ITEM VALUES FOR 'SYMBOL': >integer value in the range 1 - 227 > >ATTRIBUTE NAME: TYPE >DATABASE ITEM STRUCTURE: 10,10,C,0 >DESCRIPTION: text description of line type >ITEM VALUES FOR 'TYPE': >boundary >contact >fault >neatline > >ATTRIBUTE NAME: MODIFIER >DATABASE ITEM STRUCTURE: 20,20,C,0 >DESCRIPTION: modifier, if any, for the 'type' item above >ITEM VALUES FOR 'MODIFIER': >approximate >certain >concealed >scarp terrace > >ATTRIBUTE NAME: DESC >DATABASE ITEM STRUCTURE: 100,100,C,0 >DESCRIPTION: text description of linear geologic feature >ITEM VALUES FOR 'DESC': >(see table below) > >RELATIONSHIP OF ITEMS 'LINECODE', 'SYMBOL', 'TYPE', 'MODIFIER', and 'DESC': >LINECODE SYMBOL TYPE MODIFIER DESC >1 1 contact certain contact, certain >2 3 contact approximate contact, approximately located >3 4 boundary approximate gravel quarry boundary >6 4 boundary approximate bentonite quarry boundary >106 8 fault approximate normal fault, approximately located, queried to indicate end of recognizable feature >102 51 fault certain normal fault, certain, with bar and ball on downthrown side >4 172 contact scarp terrace contact coincident with scarp terrace, hachures on low side of scarp >101 173 fault certain normal fault, certain >103 175 fault approximate normal fault, approximately located >104 176 fault concealed normal fault, concealed >105 185 fault approximate normal fault, approximately located, with bar and ball on downthrown side >5 227 neatline neatline to define limits of geologic map area > >--------------------------------------------------------------- >COVERAGE NAME: gjpnt >--------------------------------------------------------------- > >USER-DEFINED ITEMS IN GJPNT.PAT: >------------------------------------ > >ATTRIBUTE NAME: SYMBOL >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: symbol used to draw point feature >ITEM VALUES FOR 'SYMBOL': >2 >63 > >ATTRIBUTE NAME: STRIKE >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: compass orientation of feature, in degrees >ITEM VALUES FOR 'STRIKE': >integer value in the range 0 - 360 > >ATTRIBUTE NAME: DIP >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: inclination from vertical of feature >ITEM VALUES FOR 'DIP': >integer value in the range 0 -90 > >ATTRIBUTE NAME: DESC >DATABASE ITEM STRUCTURE: 100,100,C,0 >DESCRIPTION: text description of feature >ITEM VALUES FOR 'DESC': >strike and dip of inclined bedding calculated from outcrop pattern using 3 point solution >strike and dip of inclined bedding measured in the field > >--------------------------------------------------------------- >COVERAGE NAME: gjline >--------------------------------------------------------------- > >USER-DEFINED ITEMS IN GJLINE.AAT: >------------------------------------ > >ATTRIBUTE NAME: LINECODE >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: unique numeric identifier for linear feature type >ITEM VALUES FOR 'LINECODE': >integer value in the range 107 - 120 > >ATTRIBUTE NAME: SYMBOL >DATABASE ITEM STRUCTURE: 3,3,I,0 >DESCRIPTION: line symbol to be used to draw line entities >ITEM VALUES FOR 'SYMBOL': >integer value in the range 7 - 176 > >ATTRIBUTE NAME: TYPE >DATABASE ITEM STRUCTURE: 10,10,C >DESCRIPTION: text description of line type >ITEM VALUES FOR 'TYPE': >fold >xsec_line > >ATTRIBUTE NAME: ACCURACY >DATABASE ITEM STRUCTURE: 15,15,C >DESCRIPTION: apparent accuracy of line type >ITEM VALUES FOR 'ACCURACY': >approximate >certain >concealed > >ATTRIBUTE NAME: CERTAINTY >DATABASE ITEM STRUCTURE: 15,15,C >DESCRIPTION: questionable or not questionable >ITEM VALUES FOR 'CERTAINTY': >queried > >ATTRIBUTE NAME: DESC >DATABASE ITEM STRUCTURE: 100,100,C >DESCRIPTION: >ITEM VALUES FOR 'DESC': >(see table below) > >RELATIONSHIP OF ITEMS 'LINECODE', 'SYMBOL', 'TYPE', 'ACCURACY', 'CERTAINTY', 'DESC' > >LINECODE SYMBOL TYPE ACCURACY CERTAINTY DESC >110 7 fold concealed queried concealed axis of anticline, queried to indicate end of recognizable feature >107 64 fold certain axis of anticline, certain >120 173 xsec_line cross-section location line A-A' >108 175 fold approximate axis of anticline, approximately located >109 176 fold concealed axis of anticline, concealed > Entity_and_Attribute_Detail_Citation: none 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: 303-236-5486 Contact_Electronic_Mail_Address: webmaster@geology.cr.usgs.gov Distribution_Liability: Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data, software, or related materials. These data are intended for use at 1:24,000 scale. Any hardcopies utilizing these data shall clearly indicate their source. If the user has modified the data in any way (s)he is obligated to describe the types of modifications they have performed on the hardcopy map. User specifically agrees not to misrepresent these data, nor to imply that changes they made were approved by the U.S. Geological Survey or the authors of this geologic map database. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARCE, SHP Format_Version_Number: 7.1.2 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://geology.cr.usgs.gov/pub/mf-maps/mf-2363/ 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-2363 (Map-on-Demand) Distribution_Liability: None Standard_Order_Process: Non-digital_Form: Available as one printed sheet plus one pamphlet. Order from USGS at the address listed above or see http://rmmcweb.cr.usgs.gov/pub/mod/order.html for more ordering information. Fees: for current charges please see http://rmmcweb.cr.usgs.gov/public/mod/order.html Metadata_Reference_Information: Metadata_Date: 20011228 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Robert B. Scott Contact_Position: Geologist Contact_Address: Address_Type: mailing and physical address Address: U.S. Geological Survey MS 913 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303-236-1230 Contact_Electronic_Mail_Address: rbscott@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998