Spatial digital database for the geologic map of Oregon

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Frequently anticipated questions:

What does this data set describe?

Title: Spatial digital database for the geologic map of Oregon
Abstract:
This report publishes a geologic digital spatial database (ORGEO) for the geologic map of Oregon by Walker and MacLeod (1991) which was originally printed on a single sheet of paper at a scale of 1:500,000 and accompanied by a second sheet for map unit descriptions and ancillary data. The spatial digital database (GIS) provided in this report supersedes an earlier digital edition by Raines and others (1996).
Supplemental_Information:
The digital geologic map of Oregon consists of a single coverage (ORGEO) which contains map units and lines. The feature attribute tables include a geologic linework table, ORGEO.AAT, that relates to the ORGEO.CON (contacts and boundaries), ORGEO.ST2 (structures), and ORGEO.REF (source reference) files, and a rock unit table, ORGEO.PAT, that relates to the ORGEO.RU (rock unit) and ORGEO.REF (source reference) files.
  1. How might this data set be cited?
    Walker, G.W., MacLeod, N.S., Miller, R.J., Raines, G.L., and Connors, K.A., 2003, Spatial digital database for the geologic map of Oregon: U.S. Geological Survey Open-File Report 03-67, U.S. Geological Survey, Menlo Park, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -125.391158
    East_Bounding_Coordinate: -116.418390
    North_Bounding_Coordinate: 46.355947
    South_Bounding_Coordinate: 41.906947
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2003
    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 (62104)
      • Label point (17365)
      • GT-polygon composed of chains (17364)
      • Node, planar graph (49852)
      • Point (4)
    2. What coordinate system is used to represent geographic features?
      The map projection used is Lambert Conformal Conic.
      Projection parameters:
      Standard_Parallel: 33.0
      Standard_Parallel: 45.0
      Longitude_of_Central_Meridian: -120.5
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 0.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.004511
      Ordinates (y-coordinates) are specified to the nearest 0.004511
      Planar coordinates are specified in meters
      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?
    ORGEO.AAT
    Arc Attribute Table ESRI feature attribute table for linear features (contacts, faults, and folds) (Source: ESRI)
    LINECODE
    Numeric code used to identify type of linear feature. Linecodes > 0 and < 100 are used for contacts and boundaries which are described in the ORGEO.CON file.
    Linecodes > 100 and < 600 represent structural features which are described in the ORGEO.ST2 file.
    NAME
    Name of fault This item does not contain any information, because fault names were not given in Walker and MacLeod (1991).
    SOURCE_ID
    Numeric code used to identify the data source for the linear feature.
    ValueDefinition
    1U.S. Geological Survey, 1993
    41Walker and MacLeod, 1991
    Complete references for the sources are listed in the ORGEO.REF lookp-up table.
    SPATIAL_OBJ_ID
    Non-unique numeric identifier for each object in the ORGEO feature attribute tables (ORGEO.AAT and ORGEO.PAT). (This integer is NOT duplicated in the ORGEO.PAT feature attribute table.) Values range from a low of 20200041 to a high of 410230365.
    FAULT_CONT
    Indicates if fault constitutes a contact between rock units
    ValueDefinition
    yesfault IS a contact between rock units
    nofault is NOT a contact between rock units
    (no entry)The feature is NOT a fault.
    DWNTHRWN
    Indicates the sense of movement on the fault. The side indicated by the compass direction (e, n, ne, nw, s, se, sw, or w) is downdropped. No value indicates that movement EITHER did not occur OR was not recorded.
    ValueDefinition
    eEast side of fault is downdropped with respect to the west side of the fault.
    nNorth side of fault is downdropped with respect to the south side of the fault.
    neNortheast side of fault is downdropped with respect to the southwest side of the fault.
    nwNorthwest side of fault is downdropped with respect to the southeast side of the fault.
    sSouth side of fault is downdropped with respect to the north side of the fault.
    seSoutheast side of fault is downdropped with respect to the northwest side of the fault.
    swSouthwest side of fault is downdropped with respect to the northeast side of the fault.
    wWest side of fault is downdropped with respect to the east side of the fault.
    (no entry)no movement was observed
    ORGEO.PAT
    Polygon Attribute Table: map units ESRI feature attribute table for rock units (Source: ESRI)
    MAP_UNIT
    Map unit designation (rock unit label) as it appeared on the printed Walker and MacLeod (1991) map. Map unit is described in the ORGEO.RU look-up table.
    UNIT
    Numeric code used to identify rock unit. Attributes and attribute definitions are given in the ORGEO.RU look-up table.
    SOURCE_ID
    Numeric code used to identify the data source for the rock unit. Complete references for the sources are listed in the ORGEO.REF look-up table.
    SPATIAL_OBJ_ID
    Unique numeric identifier for each object in the ORGEO feature attribute tables (ORGEO.AAT and ORGEO.PAT). (This integer is NOT duplicated in the ORGEO.AAT feature attribute table.)
    Range of values
    Minimum:410100001
    Maximum:410117371

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Walker, G.W.
    • MacLeod, N.S.
    • Miller, R.J.
    • Raines, G.L.
    • Connors, K.A.
  2. Who also contributed to the data set?
    The National Mapping Division of the U.S. Geological Survey scanned and vectorized mylar compilation sheets and converted the files to ArcInfo; Gary L. Raines and Katherine A. Connors added a data model and additional attribute data for an initial digital edition (Raines and others, 1996) of the Walker and MacLeod (1991) geologic map of Oregon.
    This second digital edition, prepared by Robert J. Miller, represents further revision of Raines and others' (1996) first edition.
  3. To whom should users address questions about the data?
    Robert J. Miller
    U.S. Geological Survey
    geologist
    345 Middlefield Road, Mail Stop 901
    Menlo Park, California
    USA

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

Why was the data set created?

This report is one of many being created by the U.S. Geological Survey as an ongoing effort to provide geologic process and mineral resource information for use in spatial analysis in a geographic information system (GIS). This database can be queried in many ways to produce a variety of geologic maps. This database is not meant to be used or displayed at any scale larger than 1:500,000 (for example, 1:100,000).

How was the data set created?

  1. From what previous works were the data drawn?
    Walker and MacLeod, 1991 (source 1 of 2)
    Walker, G.W., and MacLeod, N.S., 1991, Geologic Map of Oregon: U.S. Geological Survey, Reston, Virginia.

    Type_of_Source_Media: mylar
    Source_Scale_Denominator: 500000
    Source_Contribution:
    The map provided spatial location information in an analog format.
    Raines and others, 1996 (source 2 of 2)
    Raines, G.L., Sawatzky, D.L., and Connors, K.A., 1996, Great Basin geoscience data base: Digital Data Series DDS-41, U.S. Geological Survey, Washington, D.C..

    Type_of_Source_Media: CD-ROM
    Source_Contribution:
    The first edition (Raines and others, 1996) was used to prepare the second edition (Walker and others, 2003) of GIS for Walker and MacLeod's (1991) Geologic map of Oregon.
  2. How were the data generated, processed, and modified?
    Date: 1990 (process 1 of 5)
    George W. Walker and Norman S. MacLeod compiled the geology on 1:400,000-scale quadrants of the 1982 version of the Oregon topographic basemap.
    USGS (National Mapping Division, Thematic Map Unit) personnel digitized and reprojected the compiled geology to the 1982 1:500,000-scale state base map: this work was done on a SCITEX system. The SCITEX files were then converted to an ArcInfo format. Data sources produced in this process:
    • Walker and MacLeod, 1991
    Date: 1993 (process 2 of 5)
    Proof plots were made from the digital files and reviewed by various geologists familar with Oregon geology. A few misidentified polygons were found and the labels corrected. A data model was added and additional attributes coded.
    During the initial digitization process, lines representing faults had been captured in a file separate from the geology unit polygons. A USGS contractor edited the fault linework to connect dotted and dashed fault segments into continous lines. Fault type as well as downdrop direction were added as attributes. Data sources used in this process:
    • Walker and MacLeod, 1991
    Data sources produced in this process:
    • Raines and others, 1996
    Date: 2000 (process 3 of 5)
    For this second edition of the spatial database, the geologic unit and fault coverages were merged to produce a single topology.
    Faults forming geologic unit boundaries (contacts) occurred twice in the Raines and others (1996) dataset, once in the fault coverage (coded as a fault) and a second time in the geology coverage (coded as a "contact").
    During the process of topologically combining the two coverages, if a fault and a contact were coincident (+/- approx. 300 meters), the contact was eliminated and the remaining line retained the attribute coding inherited from the fault coverage.
    The topological combination of geology and fault cover was accomplished as follows:
    1) A buffer of fault lines was built with a buffer distance of 300 meters.
    2) The buffer was intersected with the geology coverage, thus creating nodes at the approximate ends of sections of arc in the geology coverage that are duplicated by faults.
    3) The faults were buffered again, this time at 325 meters. This buffer coverage was used to select the duplicate sections of arcs created in step 2. The selected arcs were deleted.
    4) The fault arcs were imported into the geology coverage. Dangling contacts in the coverage were extended to intersect the imported faults. Extensive proofing and editing was required to insure that the geologic unit polygons closed properly against the introduced fault arcs.
    The entire ORGEO coverage was rubbersheeted to improve the fit with a georeferenced image of the basemap. The error in registration of the Raines and others (1996) dataset was typically 200-500 meters in the western part, but reached a maximum of 800-900 meters in the eastern third of the map sheet. After adjustment, the registration of the dataset generally is within 200-400 meters. The adjustment was accomplished by defining approximately 200 adjustment links throughout the map area, then interpolating between those links to form a uniform distribution of approximately 10,000 links across the map. The high density of links provided a smooth transition in both direction and magnitude of adjustment from one area of the map to another.
    In order allow the dataset to be combined with map databases for adjacent states, modifications were made to database linework near the perimeter of the map area:
    1) the map was cropped on the north along the Washington state boundary (generally following the center of the Columbia River).
    2) the eastern and southern boundaries were replaced by state boundaries derived from USGS 1:100,000-scale Digital Line Graph (DLG) files.
    Staff at the Oregon Department of Geology and Mineral Industries reviewed the resultant geologic map database and identified thirty-one incorrectly labeled polygons. R.J. Miller then incorporated the revisions into the GIS. Data sources used in this process:
    • Raines and others, 1996
    Data sources produced in this process:
    • Walker and others, 2003
    Date: 05-Jan-2005 (process 4 of 5)
    Pamela D. Derkey ran mp 2.8.18 on the metadata file, made necessary corrections to the metadata, and imported the metadata into the ORGEO coverage.
    Date: 05-Jan-2005 (process 5 of 5)
    Creation of original metadata record Person who carried out this activity:
    Robert Miller
    U.S. Geological Survey.
    geologist
    3345 Middlefield Rd., Mail Stop 901
    Menlo Park, CA
    USA

    (650) 329-5407 (voice)
    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?
  2. How accurate are the geographic locations?
    Database linework generally fits a scanned and georeferenced image of the original printed map with an error typically of 200-300 meters. The image used for comparison had a registration RMS error of 91 meters. This information is useful only in evaluating how well the digital database recreates the original printed map, but does not provide any information regarding the locational accuracy of the geologic features shown on the original printed map.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    All geologic units were captured from Walker and MacLeod (1991) at a scale of 1:500,000.
  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 intended to be used or displayed at any scale larger than 1:500,000.
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 U.S. Geological Survey.
This database has 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.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Attn: Robert J. Miller
    geologist
    345 Middlefield Rd., Mail Stop 901
    Menlo Park, CA
    USA

    (650) 329-5407 (voice)
  2. What's the catalog number I need to order this data set? USGS Open-File Report 03-67
  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 map dataset of the Geologic map of Oregon, is not meant to be used or displayed at any scale larger than 1:500,000 (for example, 1:100,000 or 1:24,000).
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 10-Jun-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/open-file/03-67/metadata.faq.html>
Generated by mp version 2.9.48 on Tue Jul 03 20:06:22 2018