Entry_ID: (required) Entry_Title: Generalized Surficial Geologic Map of the Denver 1°x2° Quadrangle, Colorado Group: Data_Set_Citation Originator(s): David W. Moore; Arthur W. Straub; Margaret E. Berry; Michael L. Baker; Theodore R. Brandt Title: Generalized Surficial Geologic Map of the Denver 1°x2° Quadrangle, Colorado Publication: U.S. Geological Survey Miscellaneous Field Studies Map Publication_Date: 2001 Publication_Place: Denver, Colorado Publisher: U.S. Geological Survey Edition: 1.0 URL: http://pubs.usgs.gov/mf/2001/mf-2347/ End_Group Keyword: geomorphology Keyword: soil sciences Keyword: geologic maps Keyword: sedimentary rocks Keyword: glaciology Keyword: flooding Keyword: landslides Keyword: surficial geologic units Keyword: geospatial datasets Group: Temporal_Coverage Start_date: 2001 Stop_date: 2001 End_Group Data_Set_Progress: Complete Group: Spatial_Coverage Southernmost_Latitude: 39.0 Northernmost_Latitude: 40.0 Westernmost_Longitude: -106.0 Easternmost_Longitude: -104.0 End_Group Location: United States of America Location: Colorado Location: Adams County Location: Arapahoe County Location: Boulder County Location: Clear Creek County Location: Denver County Location: Douglas County Location: Elbert County Location: El Paso County Location: Grand County Location: Jefferson County Location: Park County Location: Summit County Location: Teller County Location: Golden Location: Denver Location: Castle Rock Location: Brighton Location: Littleton Location: Lakewood Location: Watkins Location: Monument Location: Parker Location: Front Range Location: Southern Rocky Mountains Location: Colorado Piedmont Location: Great Plains Group: Data_Resolution Latitude_Resolution: 200 Longitude_Resolution: 200 End_Group Access_Constraints: none Use_Constraints: none. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. Originating_Center: (required) Group: Data_Center Data_Center_Name: U.S. Geological Survey Dataset_ID: MF-2347 Group: Data_Center_Contact Last_name: U.S. Geological Survey First_name: N/A Email: webmaster@greenwood.cr.usgs.gov Phone: (303) 236-5486 Group: Address MS 902, Box 25046, Denver Federal Center Lakewood, CO 80225-0046 End_Group End_Group End_Group Group: Distribution Distribution_Media: online Distribution_Format : ARCE Distribution_Size: 0.9 Fees: none End_Group Group: Distribution Distribution_Media: online Distribution_Format : Shapefile Distribution_Size: 0.9 Fees: none End_Group Group: Multimedia_Sample URL: http://pubs.usgs.gov/mf/2001/mf-2347/mf-2347.gif Format: GIF Caption: Reduced image showing the entire map sheet. 400x203 pixels, 24-bit color. End_Group Group: Multimedia_Sample URL: http://pubs.usgs.gov/mf/2001/mf-2347/mf-2347po.pdf Format: PDF Group: Description The browse graphic file depicts a layout, featuring geologic map and supporting information. The geologic map image is colored, labeled polygons of surficial geologic units and is shown with a scanned image of roads, rivers, political boundaries, place names, and other base map features, all registered to the geologic map. These features are the standard USGS 1:250,000 base map data, including longitude and latitude, numbered UTM (meters), and the Colorado State Coordinate System (feet) grid ticks (21 internal grid tics at 15-minute intervals of longitude and latitude are visible). Supporting information includes a correlation chart of geologic map units, a list of map unit symbols and names, and a small location map that shows the quadrangle location relative to rivers, state boundaries, and locations of 26 published USGS geologic maps (1:250,000 scale) in the Colorado Plateau and western Great Plains. This PDF file is optimized for highest print quality. An accompanying pamphlet includes a complete description of map units, selected references, and a description of terminology used. End_Group End_Group Group: Reference End_Group Group: Summary The map and descriptions offer information that may be used for: land-use planning (e.g. selecting land fill sites, greenbelts, avoiding geologic hazards), for finding aggregate resources (crushed rock, sand, and gravel), for study of geomorphology and Quaternary geology. Geologic hazards (e.g., landslides, swelling soils, heaving bedrock, and flooding) known to be located in, or characteristic of some mapped units, were identified. Surficial deposits in the quadrangle partially record depositional events of the Quaternary Period (the most recent 1.8 million years). Some events such as floods are familiar to persons living in the area, while other recorded events are pre-historical. The latter include glaciation, probable large earthquakes, protracted drought, and widespread deposition of sand and silt by wind. At least twice in the past 200,000 years (most recently about 30,000 to 12,000 years ago) global cooling caused glaciers to form along the Continental Divide. The glaciers advanced down valleys in the Front Range, deeply eroded the bedrock, and deposited moraines (map units tbg, tbj) and outwash (ggq, gge). On the plains (east part of map), eolian sand (es), stabilized dune sand (ed), and loess (elb) are present and in places contain buried paleosols. These deposits indicate that periods of sand dune deposition alternated with periods of stabilized dunes and soil formation. Thirty-nine types of surficial geologic deposits and residual materials of Quaternary age are described and mapped in the greater Denver area, in part of the Front Range, and in the piedmont and plains east of Denver, Boulder, and Castle Rock. Descriptions appear in the pamphlet that accompanies the map. Landslide deposits, colluvium, residuum, alluvium, and other deposits or materials are described in terms of predominant grain size, mineral or rock composition (e.g., gypsiferous, calcareous, granitic, andesitic), thickness of deposits, and other physical characteristics. Origins and ages of the deposits and geologic hazards related to them are noted. Many lines between geologic units on our map were placed by generalizing contacts on published maps. However, in 1997-1999 we mapped new boundaries, as well. The map was projected to the UTM projection. This large map area extends from the Continental Divide near Winter Park and Fairplay ( on the west edge), eastward about 107 mi (172 km); and extends from Boulder on the north edge to Woodland Park at the south edge (68 mi; 109 km). Compilation scale: 1:250,000. Map is available in digital and print-on-demand paper formats. Deposits are described in terms of predominant grain size, mineralogic and lithologic composition, general thickness, and geologic hazards, if any, relevant geologic historical information and paleosoil information, if any. Thirty- nine map units of deposits include 5 alluvium types, 15 colluvia, 6 residua, 3 types of eolian deposits, 2 periglacial/disintegrated deposits, 3 tills, 2 landslide units, 2 glaciofluvial units, and 1 diamicton. An additional map unit depicts large areas of mostly bare bedrock. The physical properties of the surficial materials were compiled from published soil and geologic maps and reports, our field observations, and from earth science journal articles. Selected deposits in the field were checked for conformity to descriptions of map units by the Quaternary geologist who compiled the surficial geologic map units. FILES INCLUDED IN THIS DATA SET: >denvpoly: polygon coverage containing geologic unit contacts and labels. >denvline: arc coverage containing faults. >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. >color524.shd: This shadeset file defines the cmyk values of colors > assigned to polygons in the geologically themed coverages. End_Group Group: DIF_Author Last_name: Schweitzer First_name: Peter Middle_name: N Email: pschweitzer@usgs.gov Phone: 703-648-6533 Group: Address Mail Stop 954 12201 Sunrise Valley Dr Reston, VA 20192-0002 USA End_Group End_Group DIF_Revision_Date: 20150202 Science_Review_Date: