Identification_Information: Citation: Citation_Information: Originator: Melvill R. Mudge, Robert L. Earhart, James W. Whipple, Jack E. Harrison, Steven R. Munts, and Jeffery T. Silkwood Publication_Date: 2000 Title: Geologic and structure map of the Choteau 1 x 2 degree quadrangle, western Montana: a digital database. Western Montana: a digital database. Edition: Version 1.0 Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: Miscellanious Investigations Series Issue_Identification: Map I-1300 Publication_Information: Publication_Place: Menlo Park, CA Publisher: U. S. Geological Survey Online_Linkage: URL = http://pubs.usgs.gov/imap/i1300/ Description: Abstract: The geologic and structure map of Choteau 1 x 2 degree quadrangle (Mudge and others, 1982) was originally converted to a digital format by Jeff Silkwood (U.S. Forest Service and completed by the U.S. Geological Survey staff and contractor at the Spokane Field Office (WA) in 2000 for input into a geographic information system (GIS). The resulting digital geologic map (GIS) database can be queried in many ways to produce a variey of geologic maps. Digital base map data files (topography, roads, towns, rivers and lakes, etc.) are not included: they may be obtained from a variety of commercial and government sources. This database is not meant to be used or displayed at any scale larger than 1:250,000 (e.g. 1:100,000 or 1:24,000. The digital geologic map graphics and plot files (chot250k.gra/.hp/.eps and chot-map.pdf) that are provided in the digital package are representations of the digital database. They are not designed to be cartographic products. Purpose: This dataset was developed to provide geologic map GIS of the Choteau 1:250,000 quadrangle for use in future spatial analysis by a variety of users. These data can be printed in a variety of ways to display various geologic features or used for digital analysis and modeling. This database is not meant to be used or displayed at any scale larger than 1:250,000 (e.g. 1:100,000 or 1:24,000). Supplemental_Information: This GIS consists of two major Arc/Info datasets, a line and polygon file (chot250k) containing geologic contact and structures (lines) and geologic map rock units (polygons), and a point file (chot250kp) containing structural point data for plunging folds. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2000 Currentness_Reference: Publication date Status: Progress: complete Maintenance_and_Update_Frequency: As needed. Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -114.00 East_Bounding_Coordinate: -112.00 North_Bounding_Coordinate: 48.00 South_Bounding_Coordinate: 47.50 Keywords: Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: geology Place_Keyword_Thesaurus: none Place_Keyword: Montana Place_Keyword: Choteau Place_Keyword: Powell County Place_Keyword: Lewis and Clark County Place_Keyword: Lake County Place_Keyword: Flathead County Place_Keyword: Missoula County Place_Keyword: Teton County Place_Keyword: Pacific Northwest Place_Keyword: USA Access_Constraints: none Use_Constraints: This digital database is not meant to be used or displayed at any scale larger than 1:250,000 (e.g. 1:100,000). Any hardcopies utilizing these data sets shall clearly indicate their source. If the user has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. User specifically agrees not to misrepresent these data sets, nor to imply that changes they made were approved by the US Geological Survey. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Pamela D. Derkey Contact_Organization: U.S. Geological Survey Contact_Position: geologist Contact_Address: Address_Type: mailing and physical address Address: 904 W. Riverside Ave., Rm. 202 City: Spokane State_or_Province: WA Postal_Code: 99201 Country: USA Contact_Voice_Telephone: 1-509-368-3114 Contact_Facsimile_Telephone: 1-509-368-3199 Contact_Electronic_Mail_Address: pderkey@usgs.gov Data_Set_Credit: The Choteau geologic map database was initially prepared by Jef Silkwood (U.S. Forest Service) from the geologic map by Mudge and others (1982). These preliminary digital files were transferred to the U.S. Geological Survey (USGS) in 1999. Robert J. Miller (USGS) merged the geology (lines and polygons) and structure (lines) files into a single topological ArcInfo dataset. Steven R. Munts (contractor) digitized additional structural features (folds) from Mudge and others (1982). The digital files were then augmented with an interim geologic map data model (data base), further attributed and edited, and then plotted and compared to the published geologic map to check for digitizing and attribute errors. All processing by the U.S. Geological Survey was done in ArcInfo version 7.2.1 installed on a Unix-based Sun Ultra workstation. Pamela D. Derkey and Robert J. Miller (both of the USGS) provided technical assistance with the geologic systems data model, metadata, digital documentation, and map projections; Steven R. Munts (contractor) digitized new linework, edited digital files, combined existing data sets, built look-up tables, and prepared the composite dataset. Native_Data_Set_Environment: SunOS, 5.7, sun4u UNIX ARC/INFO version 7.2.1 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Attribute accuracy was verified by manual comparision of the source with hard copy printouts, plots, and on-screen evaluation. Logical_Consistency_Report: Polygon and chain-node topology present. Segments making up the outer and inner boundaries of a polygon tie end-to-end to completely enclose the area. Line segments are a set of sequentially numbered coordinate pairs. No duplicate features exist nor duplicate points in a data string. Intersecting lines are separated into individual line segments at the point of intersection. All nodes are represented by a single coordinate pair, which indicates the beginning or end of a line segment. The neat line was generated by mathematically generating the four sides of the quadrangle, densifying the lines of latitude and projecting the file to a Transverse projection (without a y-shift). Completeness_Report: All geologic units were compiled from Mudge and others (1982) at a scale of 1:250,000. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The horizontal position accuracy for the digital data is no better than 55 meters based on the digitizing RMS error. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Mudge, M.R., Earhart, R.L., Whipple, J.W., and Harrison, J.E. Publication_Date: 1982 Title: Geologic and structure map of the Choteau 1 x 2 degree quadrangle, western Montana Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: Miscellaneous Investigations Series Issue_Identification: Map I-1300 Publication_Information: Publication_Place: Denver, CO Publisher: U.S. Geological Survey Source_Scale_Denominator: 250000 Type_of_Source_Media: paper map Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1982 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: Mudge and others (1982) Source_Contribution: This is the source for all the datasets. Process_Step: Process_Description: Geologic map (Mudge and others, 1982) was initially prepared by Jef Silkwood (U.S. Forest Service) and given minimal attributing. Lithology and faults were digitized (1999) The contacts, lithology and faults datasets were compiled electronically into a single topologically correct coverage by R. J. Miller (USGS) using ARC/INFO ver. 7.2.1 on a Sun Unix system (December, 1999). S. R. Munts (contractor) edited the dataset and attributed it with an interim geologic data model. He also digitized the folds from Mudge and others (1982) on an Altek digitizing tablet (RMS input error = 0.003) and incorporated the data into the Choteau GIS. Process_Date: 1999 - 2001 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 3007 SDTS_Point_and_Vector_Object_Type: String Point_and_Vector_Object_Count: 8382 SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains Point_and_Vector_Object_Count: 3006 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Transverse Mercator Transverse_Mercator: Scale_Factor_at_Central_Meridian: 1.00000000 Longitude_of_Central_Meridian: -113 Latitude_of_Projection_Origin: 0 False_Easting: 0.000 False_Northing: 0.00000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.000000266566 Ordinate_Resolution: 0.000000266566 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 'Geologic and structure map of the Choteau 1 x 2 degree quadrangle, Montana: a digital database' report (chot250k.pdf) contains a detailed description of each attribute code and a reference to the associated map symbols on the map source materials. The GIS includes a geologic line work arc attribute table, chot250k.aat, that relates to the chot250k.con (contact look-up table), chot250k.st2 (structure look-up table), chot250k.lgu (linear geologic units table), and the chot250k.ref (source reference look-up table) files; and a rock unit polygon attribute table, chot250k.pat, that relates to the chot250k.ru (rock unit look-up table) and chot250k.ref (source reference look-up table) files; and a point attribute table, chot250kp.pat, that relates to the chot250p.sym (symbol description look-up table) and the chot250p.ref (source reference look-up table). Entity_and_Attribute_Detail_Citation: See Chot250k.pdf file available at http://pubs.usgs.gov/map/i1300/ for a detailed description of the items in the database. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Information Services Contact_Address: Address_Type: Address: City: State_or_Province: Postal_Code: Country: Contact_Voice_Telephone: Distribution_Liability: The U.S. Geological Survey (USGS) provides these geographic data "as is". The USGS makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. The USGS further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on computers at the USGS, no warranty, expressed or implied, is made by the USGS regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty. In no event shall the USGS have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by USGS. This digital geologic map GIS of the Choteau 1:250,000 quadrangle, Montana, is not meant to be used or displayed at any scale larger than 1:250,000 (e.g. 1:100,000 or 1:24,000). Metadata_Reference_Information: Metadata_Date: 20010615 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Pamela D. Derkey Contact_Position: geologist Contact_Address: Address_Type: mailing and physical address Address: 904 West Riverside Avenue, Rm 202 City: Spokane State_or_Province: WA Postal_Code: 99201 Country: USA Contact_Voice_Telephone: 1-509-368-3114 Contact_Facsimile_Telephone: 1-509-368-3199 Contact_Electronic_Mail_Address: pderkey@usgs.gov Metadata_Standard_Name: Metadata Metadata_Standard_Version: EGDC-STD-001-1998 Metadata_Access_Constraints: none Metadata_Use_Constraints: none