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This GIS dataset is reproduced from: “Best, M.G., Morris, H.T., Kopf, R.W., and Keith, J.D., 1987, Geologic map of the southern Pine Valley area, Beaver and Iron Counties, Utah: U.S Geological Survey Miscellaneous Investigations Series Map I-1794, 1 plate, scale 1:50,000.” The map covers four standard 7.5'quadrangles in southwestern Utah: Observation Knoll, The Tetons, Bible Spring, and Mountain Spring Peak.The GIS dataset was completed by David MacKay, Nathan Rau, and Jared Brabazon, students at Brigham Young University, and final GIS review and preparation for public release were completed by Zach Anderson, a geologist with the Utah Geological Survey.The UGS appreciates the volunteered time and effort of Brigham Young University students David MacKay, Nathan Rau, and Jared Brabazon who produced the GIS data for this project under the guidance of Brigham Young University professor Eric Christiansen.The southern Pine Valley area is in the Basin and Range Province of southwestern Utah and is dominated by north-south-trending mountain ranges and broad valleys. This map covers the southern end of Pine Valley where the topographic highs of the Wah Wah Mountains and Blawn Mountain area extend southwest into the Broken Ridge, North Peaks, and Indian Peak Range areas to encapsulate the southern end of Pine Valley. The ranges expose Middle to Upper Cambrian and Middle Ordovician to Upper Mississippian sedimentary rocks that compose the upper plate of the Blue Mountain thrust fault. The upper plate of the Blue Mountain thrust fault is cut by the Tetons and Dry Canyon thrust faults in the northwest portion of the map. In the north-central portion of the map, an erosional window in the lower plate of the Blue Mountain thrust exposes Jurassic and Triassic(?) Navajo Sandstone. All thrust faulting within the map area is a result of contractional deformation that occurred during the Cretaceous Sevier orogeny. Oligocene to Miocene volcanic, volcaniclastic and minor amounts of intrusive rocks unconformably overlie and intrude Paleozoic rocks. North- to northeast-striking normal faults cut Paleozoic and Cenozoic rocks and are the result of the Tertiary Basin and Range extension. The map area is cut from southwest to northeast by the Bible Spring fault zone, an anastomosing system of northeast-striking, Tertiary normal faults. The Bible Spring fault zone does not cut the younger Miocene rhyolite member of the Steamboat Mountain Formation (Tsr) but is likely the conduit for hydrothermally-altering fluids which created a geochemical anomaly within the unit. Quaternary alluvium covers the topographically lower portions of the map area. 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 geologic line symbols to better match the UGS 2018 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 1987 and does not meet all modern cartographic, spatial control, or geologic standards. Line and point attributes and symbology were selected from current (2018) UGS schema and do not necessarily match the intent of the original map. Selected attributes most closely represent the general geologic interpretation depicted on the original map, but are not an exact match, as noted below. ContactsOriginal attribute is “Contact.” These lines are now depicted as “Contact, well located.”Normal FaultsOriginal attribute is“High-angle fault – Dotted where concealed; bar and ball on downthrown side where displacement is certain.” These lines are now depicted as “Fault, normal, well located” or “Fault, normal, concealed.”General faultsLine types do not have a description in the explanation of the original map. These lines are now depicted as “Fault, unknown, well located” or “Fault, unknown, concealed.”Thrust FaultsOriginal attribute is “Thrust fault – Sawteeth on upper plate; dotted where concealed.” These lines are now depicted as “Fault, thrust, type1, well located”where older rocks are faulted over younger rocks.FoliationOriginal attribute is “Strike and dip of compaction foliation in tuffs.” These points are now depicted as “Foliation, inclined, field measured” or “Foliation, horizontal.”Units – Descriptions/Names/AgesMap is not modified from original source map even in locations where newer interpretations may exist. |