Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Cooperating agencies: Bureau of Land Management and U.S. Forest Service Author or compiler: Bradley S. Van Gosen, Richard B. Berg, and Jane M. Hammarstrom Publication_Date: 1998 Title: Map showing areas with potential for talc deposits in the Gravelly, Greenhorn, and Ruby Ranges and the Henrys Lake Mountains of southwestern Montana Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: OF 98-224-B Publication_Information: Publication_Place: Denver, Colorado Publisher: U.S. Geological Survey Online_Linkage: http://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-98-0224-b Description: Abstract: For the last several years, Montana has been the leading talc producing state in the United States. For example, in 1992 Montana supplied about 40 percent of the U.S. mine production of talc. All of this production has come from the large deposits of high purity talc in the southwestern part of the state. All Montana talc is currently (1997) extracted from four mines, each within the study area of this map--the open pit operations of the Treasure State, Regal, and Yellowstone mines and the underground operation of the Beaverhead mine. Montana talc has at least two market advantages: (1) some deposits are very large and near surface, allowing economic mining by open pit methods; and (2) the deposits are of high purity and lack tremolite or other amphibole mineral contaminants (such as absestos) that occur in some other talc-rich deposits. Talc from southwest Montana is used in ceramics, paint, paper, plastics, cosmetics, rubber, roofing, flooring, caulking, and agricultural applications. The talc is also used in the processes of recycling paper and plastics. Exploration and development are likely to continue for the foreseeable future for several reasons: (1) mines are active in the area at present and an infrastructure for talc processing exists; (2) large changes in domestic and export talc markets are not expected in the next few years based on recent market trends; (3) the talc of this region is especially pure and asbestos-free; and (4) except for potential ground stabilization problems and land disturbance associated with large-scale open pit mining, no significant environmental impacts are associated with talc mining. This map shows areas of surface exposure of Archean-age marble, which is the only rock type within the study area known to host talc deposits of economic size. Only exposed marble is shown because it is most probable that talc bodies will be discovered in this area by recognizing talc alteration in surface exposures or in the excavations of mines or prospects. The map also provides locations and brief descriptions of the talc mines, prospects, and occurrences known within the map area. The map was prepared as part of a mineral resource assessment of specified areas containing federal lands in Beaverhead and Madison Counties of southwestern Montana. The Bureau of Land Management and U.S. Forest Service chose this area for mineral resource evaluation to assist their development of land-use managment plans for the region. Purpose: The Bureau of Land Management and U.S. Forest Service use mineral resource data in developing land-use management plans for the reasonably foreseeable future. Supplemental_Information: Map political location: Beaverhead and Madison Counties, Montana Compilation scale: 1:250000 Geology compiled in 1997 and 1998; compilation completed 5/98. Review and revision completed 6/98. Paper copy published as Open-File Report 98-224-B Web version (.pdf) released on 12/08/98 ARC/INFO archive files prepared 12/7/98. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 19981208 Currentness_Reference: Published in 1998 Status: Progress: Complete. Maintenance_and_Update_Frequency: None. Mapping is continuing in adjacent areas for different purposes. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate:-113.0 East_Bounding_Coordinate:-111.25 North_Bounding_Coordinate: 45.75 South_Bounding_Coordinate: 44.5 Keywords: Theme: Theme_Keyword_Thesaurus: Geology Theme_Keyword: Geologic map Theme_Keyword: Talc Theme_Keyword: Mineral resource Place: Place_Keyword_Thesaurus: none Place_Keyword: Montana Place_Keyword: Gravelly Range Place_Keyword: Greenhorn Range Place_Keyword: Ruby Range Place_Keyword: Henrys Lake Mountains Place_Keyword: Beaverhead County, Montana Place_Keyword: Madison County, Montana Place_Keyword: Beaverhead National Forest, Montana Place_Keyword: Dillon Access_Constraints: none Use_Constraints: None. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. The map data were originally compiled and digitized at a scale of 1:250,000, and thus the data should be considered accurate only when used at that scale. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Data was entered and checked by the geologist who made the observations. Logical_Consistency_Report: Map elements were visually checked by the author for overshoots, undershoots, duplicate features, and other errors. This digital release is preliminary and has not been thoroughly reviewed for conformity with U.S. Geological Survey editorial standards or stratigraphic nomenclature. The paper copy (Open-File Report 98-224-B) was reviewed by one other geologist for consistency with basic geologic principles and general conformity to USGS mapping standards. Completeness_Report: This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or stratigraphic nomenclature. This ARC/INFO release is provided only to be used with the published Open-File Report 98-224-B (paper copy). The topographic base map used for the paper copy release was scanned and included as the base for the paper copy; this base is not currently available separately. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Lines were digitized from original source maps at their original scales and projections, then composited at the final scale and projection in GSMAP. Lineage: Process_Step: Process_Description: The geologic database was compiled using the GSMAP public domain program (USGS Open-File Report 93-511) and later upgraded to the Windows version of GSMAP-- GSMCAD public domain program (USGS Open-File Report 96-007). It was exported to ARC/INFO using the GSMCAD export function to create ARC/INFO generate files. The ARC/INFO generate files were reloaded into ARC/INFO programs and attributed to match the published map (Open-File Report 98-224-B). Process_Date: 12/07/98 08:00 AM Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: TRANSVERSE MERCATOR Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -112.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 0.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.001 Ordinate_Resolution: 0.001 Planar_Distance_Units: METERS Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: The data is supplied in two formats: 1. Adobe Acrobat 3.0 .pdf format 2. UNIX based ARC/INFO format DATABASE STRUCTURE - ARC/INFO ==================================== The database of the map consists of two coverages (root names = TALC and TALC_P) and three additional auxiliary files: TALC.E00: ARC/INFO interchange file that can be used to create the geology shown on Open-File Report 98-224-B. TALC_P.E00: ARC/INFO interchange file that can be used to create point files that display the locations of the 57 talc mines, prospects, and occurrences shown on Open-File Report 98-224-B. Auxiliary files: TALC.AML: ARCPLOT commands that create the geologic map of Open-File Report 98-224-B from the data bases. TALC.COL: A look-up table of the polygon attributes in TALC.E00. TALC.PNT: A look-up table of the point attributes in TALC_P.E00. Entity_and_Attribute_Detail_Citation: Database root name: TALC P1 VALUE AND LETTER SYMBOLS FOR GEOLOGIC UNITS MAPPED======= CODE | FEATURE 1, (Archean marble, no tag) 1,1 2,2/5 3,3 4,4/56 6,6 7,7 8,8 9,9/32 10,10 11,11 12,12 13,13 14,14 15,15 16,16 17,17 18,18 19,19 20,20 21,21 22,22 23,23 24,24 25,25 26,26 27,27 28,28 29,29 30,30 31,31 33,33 34,34 35,35 36,36 37,37 38,38 39,39 40,40 41,41 42,42 43,43 44,44 45,45 46,46 47,47 48,48 49,49 50,50 51,51 52,52 53,53 54,54 55,55 57,57 FEATURES IN THE DATABASE------------------------- CODE | FEATURE 010 | study area boundary 020 | map unit contact 500 | map label for site of talc mine, prospect, or occurrence Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Mineral Resources Program Contact_Address: Bradley S. Van Gosen Address_Type: mailing address Address: U.S. Geological Survey Address: MS 905, Box 25046, Denver Federal Center City: Lakewood State_or_Province: CO Postal_Code: 80225-0046 Contact_Voice_Telephone: (303) 236-1566 office Contact_Voice_Telephone: (303) 236-1800 secretary (Joan Luce) Contact_Electronic_Mail_Address: bvangose@usgs.gov Distribution_Liability: Although this digital spatial data has been subjected to rigorous review and is substantially complete, it is released on the condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARC/INFO Format_Version_Number: Version 7.1.1 Format_Version_Date: 1997 File_Decompression_Technique: None Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address Network_Resource_Name: http://greenwood.cr.usgs.gov Fees: None Metadata_Reference_Information: Metadata_Date: 19981207 Metadata_Review_Date: 19981207 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Bradley S. Van Gosen Contact_Organization: U.S. Geological Survey, Mineral Resources Program Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Address: MS 905, Box 25046, Denver Federal Center City: Lakewood State_or_Province: CO Postal_Code: 80225-0046 Contact_Voice_Telephone: (303) 236-1566 office Contact_Voice_Telephone: (303) 236-1800 secretary (Joan Luce) Contact_Electronic_Mail_Address: bvangose@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: 19940608