Geologic map of the Stillwater Complex, Montana: a digital database

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Frequently anticipated questions:


What does this data set describe?

Title:
Geologic map of the Stillwater Complex, Montana: a digital database
Abstract:
This report provides a digital version of the Geologic map of the Stillwater Complex, Montana originally published by N. Page and W. Nokleberg (1974). Paper copies of the four geologic map sheets from the original report were scanned and initially attributed by Optronics Specialty Company (Northridge, CA) and remitted to the U.S. Geological Survey for further attribution and publication of the geospatial digital files. The resulting digital geologic dataset can be queried in a geographic information system (GIS) in many ways to produce a variety of geological maps.
Supplemental_Information:
This GIS dataset consists of two Arc/Info datasets. The first is a line and polygon file (i797) containing geologic contacts and structures (lines) and geologic map rock units (polygons). A second file contains structural point data (i797p). Since the topographic base map for the original publication is no longer readily available, a georeferenced image (tiff) of the original basemap is also included.
  1. How might this data set be cited?
    Page, Norman J, Nokleberg, Warren J., and Miller, Robert J., 2002, Geologic map of the Stillwater Complex, Montana: a digital database: U.S. Geological Survey Miscellaneous Investigations Series Map I-797, U.S. Geological Survey, Menlo Park, CA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -110.247638
    East_Bounding_Coordinate: -109.736573
    North_Bounding_Coordinate: 45.520307
    South_Bounding_Coordinate: 45.327177
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2002
    Currentness_Reference:
    publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Complete chain (11665)
      • Label point (3903)
      • GT-polygon composed of chains (3903)
      • Point (114)
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: State Plane Coordinate System 1927
      State_Plane_Coordinate_System:
      SPCS_Zone_Identifier: 2503
      Lambert_Conformal_Conic:
      Standard_Parallel: 44.866667
      Standard_Parallel: 46.400000
      Longitude_of_Central_Meridian: -109.5
      Latitude_of_Projection_Origin: 44.0
      False_Easting: 2000000.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.001195
      Ordinates (y-coordinates) are specified to the nearest 0.001195
      Planar coordinates are specified in survey feet
      The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.978698.
  7. How does the data set describe geographic features?
    i797.aat
    LINECODE
    NAME
    SOURCE
    SHEET
    i797.pat
    UNIT
    SOURCE
    LABEL-ALPHA
    SHEET
    Entity_and_Attribute_Overview:
    The i797geo dataset includes:
    1) A geologic linework arc attribute table, i797geo.aat, that relates to the i797geo.con contact look-up table, i797geo.con; a structure look-up table, i797geo.st2, and a source reference look-up table i797geo.ref
    2) A rock unit polygon attribute table, i797geo.pat, that relates to the rock unit look-up table i797geo.ru and source reference look-up table i797geo.ref.
    The i797p dataset includes a structural point data attribute table, i797p.pat, that relates to the symbol look-up table i797p.lut and source reference look-up table i797geo.ref.
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/imap/i797/i797.pdf

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Norman J Page
    • Warren J. Nokleberg
    • Robert J. Miller
  2. Who also contributed to the data set?
    Optronics Specialty Company scanned the four geologic map sheets of Page and Nokleberg (1974) and provided minimally attributed ArcInfo interchange-format files to the USGS.
    Helen Z. Kayser (contractor) registered and transformed to the datasets to the Montana state plane coordinate system.
    Robert Miller combined the 8 individual sheet files into the two theme (geology and structural data) datasets, attached and attributed an interim geologic map data model; and visually compared the hard copy plots with the source documents.
  3. To whom should users address questions about the data?
    Robert J Miller
    U.S. Geological Survey, GEO-WRG-MRS
    Mail Stop 901
    345 Middlefield Rd
    Menlo Park, CA
    USA

    650-329-5407 (voice)
    650-329-5490 (FAX)
    rjmiller@usgs.gov

Why was the data set created?

This dataset was developed to provide a spatial database of the 1:12,000 scale geologic map of the Stillwater Complex for use in future spatial analysis. 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 1:12000. The digital geologic map graphics and plot files (i797.gra/ps and i797-map.pdf) that are provided in the digital package are representations of the digital database. They are not designed to be cartographic products.

How was the data set created?

  1. From what previous works were the data drawn?
    (source 1 of 1)
    Page, N.J., and Nokleberg, W.N., 1974, Geologic map of the Stillwater Complex, Montana: U.S. Geological Survey Miscellaneous Investigations Map I-797, U. S. Geological Survey, Reston, Virginia.

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 12000
    Source_Contribution:
    This map was the only map used to create the digital geologic map database.
  2. How were the data generated, processed, and modified?
    Date: 2000 (process 1 of 4)
    Optronics Specialty Company scanned the published paper geologic map sheets
    Date: 2001 (process 2 of 4)
    The digital files were registered and transformed to state plane coordinate system by Helen Z. Kayser (contractor) at the USGS Spokane Field Office. R Miller combined the datasets and applied an interim geologic map data model. The data were then checked for position and attribute accuracy by comparing plots of the digital data to the source maps.
    (process 3 of 4)
    Low resolution scans (100 dpi) of portions of the basemap were georeferenced and converted to Arc/Info grids. The grids were clipped and merged into a single file then saved in a TIFF format. Person who carried out this activity:
    Robert J Miller
    U.S. Geological Survey, GEO-WRG-MRS
    Mail Stop 901
    345 Middlefield Rd
    Menlo Park, CA
    USA

    650-329-5407 (voice)
    650-329-5490 (FAX)
    rjmiller@usgs.gov
    Date: 21-Feb-2002 (process 4 of 4)
    Creation of original metadata record Person who carried out this activity:
    Robert J Miller
    U.S. Geological Survey, GEO-WRG-MRS
    Mail Stop 901
    345 Middlefield Rd
    Menlo Park, CA
    USA

    650-329-5407 (voice)
    650-329-5490 (FAX)
    rjmiller@usgs.gov
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    The attribute accuracy was verified by manual comparison of the source with hard copy printouts, plots, and on-screen evaluation. Further digital review was performed as part of the USGS publication process. This included automated searching for missing or incorrect attributes.
  2. How accurate are the geographic locations?
    The horizontal position accuracy for the digital data is no better than +/- 18 feet for the east half of map (sheet 1 and 2 of original publication) and +/- 8 feet for western half ( sheets 3 and 4 of the original) based on the digitizing root mean square (RMS) error. The geologic mapping was compiled on a topographic basemap map made for the project. This basemap locally differs from modern 1:24,000 topographic maps of the area, and thus geologic linework may locally appear mislocated when viewed with other than the original publication basemap.
    The individual scanned images of parts of the basemap typically had an RMS error of approximately 3 meters. However, where parts of the georeferenced scans overlap, local shifts of up 15 meters were noted..
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    All geologic units were compiled from Page and Nokleberg (1974) at a scale of 1:12,000.
  5. How consistent are the relationships among the observations, including topology?
    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.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: none
Use_Constraints:
This digital database is not meant to be used or displayed at any scale larger than 1:12,000 (e.g. 1:6,000).
Any hardcopies utilizing these data * 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 this data set, nor to imply the U.S. Geological Survey approved changes the user has made.
  1. Who distributes the data set? (Distributor 1 of 1)
    USGS Information Services
    Box 25286 Denver Federal Center
    Denver, CO
    USA

    1-888-ASK-USGS (voice)
    303-202-4693 (FAX)
    ask@usgs.gov
  2. What's the catalog number I need to order this data set? USGS Miscellaneous Investigations Map I-797
  3. What legal disclaimers am I supposed to read?
    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 Stillwater Complex, Montana, is not meant to be used or displayed at any scale larger than 1:12,000.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 05-Feb-2016
Metadata author:
Peter N Schweitzer
USGS Midwest Area
Collection manager, USGS Geoscience Data Clearinghouse, http://geo-nsdi.er.usgs.gov/
Mail Stop 954
12201 Sunrise Valley Dr
Reston, VA
USA

703-648-6533 (voice)
703-648-6252 (FAX)
pschweitzer@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://geo-nsdi.er.usgs.gov/metadata/map-i/797/geology.faq.html>
Generated by mp version 2.9.48 on Tue Jul 03 20:04:57 2018