Compilation of Stratigraphic Thicknesses for Caldera-Related tertiary Volcanic Rocks, East-Central Nevada and West-Central Utah By Donald S. Sweetkind and Edward A. du Bray, 2007 U.S. Geological Survey Data Series 271 U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark D. Myers, Director For more information about the Compilation of Stratigraphic Thicknesses for Caldera-Related tertiary Volcanic Rocks, East-Central Nevada and West-Central Utah please contact: Don Sweetkind U.S Geological Survey, Central Mineral Resources Team Denver Federal Center, Mail Stop 973 Lakewood, CO 80225-0046 Phone: 303-236-1828 FAX: 303-236-3200 e-mail: dsweetkind@usgs.gov I. Introduction These data were developed provide a general understanding of the distribution and thickness of Tertiary ash-flow tuffs within intermontane basins in east-central Nevada and western Utah. Proposed ground-water development in White Pine County, Nevada, and adjacent areas in Nevada and Utah could impact water accumulations in three general types of aquifer materials: consolidated Paleozoic carbonate bedrock, and basin-filling Cenozoic volcanic rocks and unconsolidated Quaternary sediments. At present, the full impact of extracting ground-water from any or all of these potential, valley graben reservoirs is not fully understood. A thorough understanding of intermontane basin stratigraphy, mostly concealed by the youngest unconsolidated deposits that blanket the surface in these valleys, is critical to an understanding of the regional hydrology in this area. This data set is a literature-based compilation of geologic data, especially thicknesses and lithologic characteristics, for Tertiary volcanic rocks that are presumably present in the subsurface of the intermontane valleys that are prominent features of this area. The data presented here were prepared as part of the Basin and Range Carbonate Aquifer System study, or the BARCAS study, by the U.S. Geological Survey between 2005 and 2007. II. DISCLAIMERS: This publication was prepared by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. Although all data and software published in this product have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and (or) the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials. These files have been approved for release and publication by the Director of the 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. III. SYSTEM REQUIREMENTS Minimum System Requirements Windows-based computer: A. Intel Pentium processor computer (486 minimum, Pentium or Pentium Pro recommended),with Microsoft Windows XP, Windows 2000, Windows NT 4.0 with Service Pack 5 or later Windows 98 Second Edition, or Windows 95 Service Release 2 (OSR2) 128 MB of RAM B. Macintosh computer: Power PC G3, G4, G5 processor Mac OS X v. 10.2.8 or higher 128 MB of RAM C. ArcGIS 9.2 on PC-Intel Windows XP CPU speed: 1.0 GHz recommended or higher Processor: Intel Pentium or Intel Xeon Processors Memory/RAM: 512 MB minimum, 1 GB recommended or higher Screen resolution: 1024 x 768 recommended or higher Display properties: Greater than 256 color depth Swap space: Determined by the operating system, 500 MB minimum Disk space: 50 MB IV. INSTRUCTIONS AND DOCUMENTATION FOR U.S. GEOLOGICAL SURVEY DATA SERIES 271 A. To access the data: The data files can accessed from CD or be downloaded via the web from http://pubs.usgs.gov/ds/271 This product contains Portable Document Format (.pdf) files, which require Adobe Acrobat for viewing. Acrobat software runs on a variety of systems, and is available for download free of charge from Adobe at http://www.adobe.com. This product contains excel format (.xls) files, which require an excel viewer. A viewer is available for download free of charge from Microsoft at : http://www.microsoft.com. Software Required: Adobe Acrobat Reader version 4.0 or higher ArcGIS 9.1 or later This CD-ROM contains data files, in ascii format and as an ArcGIS 9.2 personal geodatabase, that correspond to the thickness (isopach) maps of the individual tuffs discussed in the report (figs. 5-15) and the aggregate thickness (isopach) map of all tuffs for caldera-related Tertiary volcanic rocks in east-central Nevada and west-central Utah (fig. 16). The CD-ROM also contains ArcGIS 9.2 project files that enable the user to symbolize the thickness maps to match their portrayal in the figures of the report. The data may be accessed in two ways: (1) by using or converting ascii files; or (2) by using the personal geodatabase. To convert the ascii files to an ArcGIS raster data set, the user will need to convert the files within ArcToolbox using the “ASCII to Raster” tool. The tool will prompt the user to navigate to the source ascii file and create a filename for the raster data to be created. To access the data using the personal geodatabase, the user should view the CD-ROM in ArcCatalog and copy the geodatabase to the user’s computer. Using ArcCatalog will ensure that all system files are copied along with the geodatabase. The user may then add the geodatabase and the raster data inside the geodatabase directly to an ArcGIS 9.2 ArcMap project. To view the data using the same symbology as shown in the report, the user will add an ArcGIS LAYER file to an ArcMap document and then assign to that LAYER file a raster data source that corresponds to either the converted ascii file or a raster dataset within the geodatabase. B. Contents The CD contains the following files and folders: 00Readme.txt – This file is a text document. DS-271_Report.pdf – The report text, figures and tables. DS271_Tables_1_13.xls - These are tables of the stratigraphic thicknesses for caldera-related Tertiary volcanic rocks, east-central Nevada and west-central Utah. DS_271_metadata Exported FGDC-compliant metadata from ArcCatalog and debugged using USGS Geospatial Metadata Validation Service (FGDC metadata standard FGDC-STD-001-1988)-mp 2.9.5 ---see http://www.fdgc.gov/metadata/csdgm/ metadata output formats included: 1. ds271_metadata_final.xml -valid parser format mp2.9.5 (http://geo-nsdi.er.usgs.gov/validation/) 2. ds271_metadata_final.sgml -valid parser format mp2.9.5 (http://geo-nsdi.er.usgs.gov/validation/) 3. ds271_metadata_final.txt 4. ds271_metadata_final.htm DS_271_spatial - a folder that contains a ZIP file that includes all of the spatial data sets as follows: isopach_data.mdb – an ARCGIS 9.2 personal geodatabase which contains raster catalog: "iso_grids_catalog" and the following raster data sets within the raster catalog and as stand-alone raster data in their own folders: 1.condor_ipach 2.cotton_ipach 3.harmony_ipach 4.ipach_volcs (master grid compiled through grid addition) 5.isom_ipach 6.kalam_ipach 7.leach_ipach 8.lund_ipach 9.monot_ipach 10.shingle_ipach 11.wahwah_ipach 12.windous_ipach Twelve ArcGIS 9.2 “Layer” files, and ArcGIS auxilliary files, that are used to symbolize the thickness maps to match their portrayal in the figures of the report, as follows: Condor Canyon Formation.lyr Cottonwood Wash Tuff.lyr Harmony Hills Tuff.lyr Ipach_volcs.lyr (the layer file for symbolizing the aggregate thickness map) Isom Formation.lyr Kalamazoo Tuff.lyr Leach Canyon Formation.lyr Lund Formation.lyr Monotony Tuff.lyr Shingle Pass Tuff.lyr Wah Wah Springs Tuff.lyr Windous Butte Tuff.lyr ascii_grids A folder that contains the volcanic-rock thickness grids exported from ArcCatalog to ascii format. isopach_data.idb An ArcGIS 9.2 system folder that is linked to the personal geodatabase. Contains no user-accessible files. info An ArcGIS 9.2 system folder. Contains no user-accessible files.