Title: Geologic map of the San Antonio Mountain Area, northern New Mexico and southern Colorado By Kenzie J. Turner, Ren A. Thompson, Michael A. Cosca, Ralph R. Shroba, Christine F. Chan, and Leah E. Morgan 2018 U.S. Geological Survey Scientific Investigations Map 3417 U.S. Geological Survey data release https://doi.org/10.5066/F72N51M5 ABSTRACT: The geologic map of the San Antonio Mountain area in northern New Mexico and southern Colorado is located along the west-central part of the San Luis Valley. The San Luis Valley is the geomorphic expression of the San Luis Basin, an extensional basin associated with the northern Rio Grande rift. Deposits within the map area record volcanic, sedimentary, and tectonic processes over the last ~33 million years. Oldest exposed deposits include Oligocene volcanic rocks associated with the southeast San Juan Mountains locus of volcanism within the Southern Rocky Mountains volcanic field. Overlying deposits of the Southern Rocky Mountains volcanic field are volcaniclastic sedimentary rocks interbedded with predominantly basaltic lava flows of Oligocene to Miocene age. Basalt to rhyolite volcanic rocks of the Pliocene to Pleistocene Taos Plateau volcanic field unconformably overlie Oligocene to Miocene volcanic and sedimentary deposits. Superposed on the Tertiary deposits are Pleistocene to Holocene alluvial and colluvial deposits. North- to northwest-trending faults displace rocks within the map area. Magnitude of deformation is broadly correlative with age of the deposits inasmuch as Oligocene to Miocene rocks display a greater degree of fault displacement and east tilting than Pliocene volcanic rocks. Within the map area, faults displace Oligocene to Miocene deposits 10–30 meters with generally down-to-west offset, and the units dip eastward 3–7 degrees. Pliocene volcanic rocks exhibit shallower eastward dips inferred primarily from the slope of upper lava flow surfaces that dip eastward from 1–3 degrees and lava flows are generally displaced less than 5 meters. DISCLAIMERS: This database, identified as SIM3417, has been approved for release by the U.S. Geological Survey (USGS). Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty, expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey. Although this information product, for the most part, is in the public domain, it also may contain copyrighted material as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. REPORT FILES: The map, pamphlet, and readme files for this report are located at and can be downloaded via the Web from at the U.S. Geological Survey publications website at https://doi.org/10.3133/sim3417 List of files: sim3417_ReadMe.txt sim3417.pdf sim3417_georeferenced.pdf HOW TO OBTAIN THE REPORT FILES The map product is a Portable Document Format (.pdf) map, which requires Adobe Acrobat for viewing. The Portable Document Format (PDF) file can be downloaded, from which paper copies may be printed. Acrobat software runs on a variety of systems, and is available for download free of charge from Adobe at http://www.adobe.com. Suggested citation: Turner, K.J., Thompson, R.A., Cosca, M.A., Shroba, R.R., Chan, C.F., and Morgan, L.E., 2018, Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado: U.S. Geological Survey Scientific Investigations Map 3417, scale 1:50,000, https://doi.org/10.3133/sim3417. The map sheet can be obtained via the Internet from the U.S. Geological Survey publications website. Go to the web page at https://doi.org/10.3133/sim3417/ and follow the directions to download the files. DATA RELEASE GIS AND OTHER FILES The GIS database and geochemistry and geochronology analytical data (data release) for this report is located at and can be downloaded via the Web from ScienceBase at https://doi.org/10.5066/F72N51M5 List of files: SanAntonioMountain_metadata.txt SanAntonioMountainSampleLocations.csv SanAntonioMountain40Ar39ArGeochronology.csv SanAntonioMountainGeochemistry.csv ArgonDataDictionary.csv SanAntonioMountain_base.tif/.tfw (San Antonio Mountain area sim3417 topographic base) SanAntonioMountain_hillshade.tif/.tfw (San Antonio Mountain area sim3417 shaded relief base) SanAntonioMountain_SIM3417.gdb GeologicMap OrientationPoints GeochemistryPoints GeochronologyPoints CartographicLines ContactsAndFaults GeologicLines DataSourcePolys MapUnitPolys OverlayPolys DataSources DescriptionOfMapUnits GeoMaterialDict Glossary shapefiles directory: OrientationPoints.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) point GeochemPoints.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) point GeochronPoints.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) point CartographicLines.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) line ContactsAndFaults.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) line GeologicLines.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) line DataSourcePolys.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) polygon MapUnitPolys.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) polygon OverlayPolys.shp (.dbf/.prj/.sbn/.sbx/.shx.xml/.shx) polygon SanAntonioMountain_SIM3417.gdb directory (contains GIS data as geodatabase feature classes). HOW TO OBTAIN THE DIGITAL GIS FILES: The digital files constituting the geologic map database of this report can be obtained via the Internet from the U.S. Geological Survey ScienceBase website. Go to the web page at https://doi.org/10.5066/F72N51M5 and follow the directions to download the files. ArcReader may be downloaded free of charge from http://www.esri.com/software/arcgis/arcreader/download for viewing additional files included in this report. Suggested citation: Turner, K.J., Thompson, R.A., Cosca, M.A., Shroba, R.R., Chan, C.F., and Morgan, L.E., 2018, Data release of geospatial map database, argon geochronology and geochemistry data for geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado: U.S. Geological Survey data release, https://doi.org/10.5066/F72N51M5. These maps are offered as an online-only, digital publication. Users should be aware that, because of differences in rendering processes and pixel resolution, some slight distortion of scale may occur when viewing it on a computer screen or when printing it on an electronic plotter, even when it is viewed or printed at its intended publication scale.