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This GIS dataset was completed in 2017 by the Utah Geological Survey (UGS) and is reproduced from Thaden, R.E., Trites, A.F., Jr., and Finnell, T.L., 1964, Geology and ore deposits of the White Canyon area, San Juan and Garfield Counties, Utah: U.S. Geological Survey Bulletin 1125, 166 p., 4 pl., scale 1:48,000. This dataset represents geologic map features of the greater central Colorado River-White Canyon-Red Canyon area and includes parts of Glen Canyon National Recreation Area, Natural Bridges National Monument, and Bears Ears National Monument in southeastern Utah. The map is compiled for use at 1:48,000 scale. The map depicts geologic formations, faults, paleo-channels, structural contours, mines, and other information, and is accompanied by explanatory information including map-unit descriptions, geologic symbols, and a 166-page bulletin.The White Canyon area includes about 700 square miles in the west-central part of San Juan County and the eastern part of Garfield County, southeastern Utah, near the center of the Colorado Plateau physiographic province. Sedimentary formations ranging in age from Pennsylvanian to Jurassic crop out in the map area. The map area is on the west flank of the Monument upwarp, and strata have a regional dip of 2° to 3° westward. Low-amplitude flexures locally modify the regional dip of the strata. Vertical and steeply dipping normal faults are in the southwestern part of the area; grabens and horsts are bounded by normal faults that trend mostly N. 60°-80° W., and dip 65° to vertical, but some trend N. 50°-60° E. The most conspicuous joints in the area are nearly vertical and trend N. 65° W., N. 35° E., N. 65° E., and due north.Mineral deposits in the map area are copper-uranium and copper deposits in the Shinarump Conglomerate Member of the Chinle Formation. Most of the uranium and copper is localized in medium- to coarse-grained and conglomeratic sandstone interbedded with mudstone that fills channels cut into the Moenkopi Formation. Seventy-five channels were mapped—16 of them contain at least one uranium deposit having a grade of 0.10 percent or more U3O8. At least eight additional channels contain uraniferous material. Many different minerals associated with uranium are found elsewhere in the quadrangle. Descriptions of ore deposits and guides to locate ore bodies are reported in the original bulletin.This dataset was produced as part of a UGS multi-decade effort to provide statewide intermediate-scale (approximately 1:50,000 to 1:100,000) GIS data to the public, federal to local government agencies, educational groups, exploration and development companies, and other map users. The GIS dataset reproduces the original source map as close as reasonably possible; however, some geologic decisions were made to resolve cartographic problems such as inconsistent faults and incomplete polygons. We changed some unit names, geologic line symbols, and unit descriptions to better match newer mapping in the area and the UGS 2017 data model. While the map is considered a good representation of the geology of the map area, users should be aware that it was produced in 1964 and does not meet all modern cartographic, spatial control, or geologic standards. Not all features on the original map precisely match options in the 2017 UGS geologic map schema as noted below.Normal faultsLine attributes and symbology were selected from current (2017) UGS schema and do not necessarily match the intent of the original map. Selected attributes most closely represent the general geologic interpretation depicted by the original map, but are not an exact match. Original attributes are “Fault, showing dip – Dashed where approximately located; dotted where concealed; U, upthrown side; D, downthrown side.” These lines are now depicted as “Fault, normal, well located,” “Fault, normal, concealed,” or “Fault, normal, approximately located.”General faultsLine attributes and symbology were selected from current (2017) UGS schema and do not necessarily match the intent of the original map. Selected attributes most closely represent the general geologic interpretation depicted by the original map, but are not an exact match. Some line types do not have a description in the explanation of the original map. These lines are now depicted as “Fault, unknown, well located,” “Fault, unknown, approximately located,” or “Fault, unknown, concealed.”Structure contoursLine attributes and symbology were selected from current (2017) UGS schema and do not necessarily match the intent of the original map. Selected attributes most closely represent the general geologic interpretation depicted by the original map, but are not an exact match. Original attributes are “Structure contour – Drawn on top of the Wingate sandstone and Hoskinnini member - Dashed where approximately located.” These lines are now depicted as “Structure contour, datum 1,” “Structure contour, datum 1, projected above ground,”“Structure contour, datum 2,” or “Structure contour, datum 2, projected above ground.”Paleo Channel FillsLine attributes and symbology were selected from current (2017) UGS schema and do not necessarily match the intent of the original map. Selected attributes most closely represent the general geologic interpretation depicted by the original map, but are not an exact match. Original attributes are “Channel filled with sediments of the Shinarump member of the Chinle formation – Dashed where inferred.” These lines are now depicted as “Paleo-Channel fill, well located” or “Paleo-Channel fill, approximately located.”Units – Unit Symbols/Names/AgesThe following changes in formation and unit names were made to partially match modern usage in the area:Qt – Tufa is now Qst – Spring tufa, Ql – Landslides is now Qms – Mass movement landslides, Qld – Lacustrine deposits is now Ql – Lacustrine deposits, Qg – Gravel is now Qatg – Terrace gravel, Qtb – Talus breccia is now Qmt – Mass movement talus deposits, Qcl – Colluvium is now Qc – Colluvium, Qd – Dune sand is now Qed – Eolian dune sand, Jsr – San Raphael group, undifferentiated is now Jtcc – Temple Cap Formation (former Page Ss) and Carmel Formation, TRw – Wingate sandstone is now JTRw – Wingate Sandstone, TRcss – siltstone-sandstone unit of the Chinle Formation is now TRcc – Church Rock Member of Chinle Formation, TRcl – limy unit of the Chinle Formation is now TRcop – Owl Rock and Petrified Forest Members of Chinle Formation, TRcm – Moss Back member of the Chinle Formation is now TRcms – Moss Back Member of Chinle Formation, TRcms – mudstone-sandstone unit of the Chinle Formation is now TRcmn – Monitor Butte Member of Chinle Formation, Pcw – White Rim sandstone member of the Cutler formation is now Pwr – White Rim Sandstone, Pco – Organ Rock tongue of the Cutler formation is now Po – Organ Rock Formation, Pcc – Cedar Mesa sandstone member of the Cutler formation is now Pcm – Cedar Mesa Sandstone, PIPr – Rico formation is now PIPcl – lower Cutler beds (Halgaito Formation), and IPh – Hermosa formation is now IPht – Honaker Trail Formation.Ages were also slightly modified to match modern usage. |