Geologic Map of the Scotts Mills, Silverton, and Stayton Northeast 7.5 Minute Quadrangles, Northwest Oregon: A Digital Database: Silverton Quadrangle

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
Geologic Map of the Scotts Mills, Silverton, and Stayton Northeast 7.5 Minute Quadrangles, Northwest Oregon: A Digital Database: Silverton Quadrangle
Abstract:
This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits of the Silverton 7.5 minute quadrangle along the eastern margin of the Willamette Valley and adjacent lower foothills (Waldo and Silverton Hills) of the Cascade Range. The major emphasis of this investigation was to identify and map Columbia River Basalt Group (CRBG) units and to utilize this detailed CRBG stratigraphy to identify and characterize structural features. Together with the accompanying text file (geol.txt or geol.ps), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24.000 or smaller.
  1. How might this data set be cited?
    Tolan, Terry, Beeson, Marvin, and Wheeler, Karen L., 1999, Geologic Map of the Scotts Mills, Silverton, and Stayton Northeast 7.5 Minute Quadrangles, Northwest Oregon: A Digital Database: Silverton Quadrangle: U.S. Geological Survey Open-File Report 99-141.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.88
    East_Bounding_Coordinate: -122.75
    North_Bounding_Coordinate: 45.13
    South_Bounding_Coordinate: 45.00
  3. What does it look like?
    http://pubs.usgs.gov/of/1999/0141/pdf/svsc.pdf (PDF)
    A PDF representation of both Scotts Mills and Silverton quadrangles (sheet 1).
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 1999
    Currentness_Reference:
    Publication of digital geologic map database
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: map
  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):
      • entity point
      • complete chain
      • GT-polygon composed of chains
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 10
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -123
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000
      False_Northing: 0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest unknown
      Ordinates (y-coordinates) are specified to the nearest unknown
      Planar coordinates are specified in meters
  7. How does the data set describe geographic features?
    SLV_GEO.PAT
    Silverton Geologic map units (Source: OFR-99-0141)
    PTYPE
    Polygon type (Source: OFR-99-0141)
    ValueDefinition
    QalAlluvial deposits (Holocene)
    QoalQoal
    TfshBasalt of Sand Hollow (middle Miocene) - Frenchman Springs Member, Wanapum Basalt
    TfsfBasalt of Silver Falls (middle Miocene) - Frenchman Springs Member, Wanapum Basalt
    TgsbSentinel Bluffs member (middle Miocene) - Grande Ronde Basalt
    TgwwWinter Water member (middle Miocene) - Grande Ronde Basalt
    TgouOrtley and Umtanum members (middle Miocene) - Grande Ronde Basalt
    TsmScotts Mills Formation-undifferentiated (Oligocene to lower Miocene?) - Grande Ronde Basalt
    SLV_GEO.AAT
    Linear geologic map features (Source: OFR-99-0141)
    LTYPE
    Line type (Source: OFR-99-0141)
    ValueDefinition
    contact, inferredcontact whose position is not known and inferred
    fault, concealedConcealed and inferred fault
    map boundaryOutside boundary of mapped area
    normal fault, concealedA normal fault whose position is concealed and inferred
    normal fault, concealedmMainly concealed normal fault
    normal fault, inferredA normal fault whose position was not observed and inferred
    normal fault, inferredmA normal fault whose position is mainly(?) inferred.
    SLV_GEO.PAT
    Geologic unit at specific points (Source: OFR-99-0141)
    PTYPE
    Point Type (Source: OFR-99-0141)
    ValueDefinition
    QalAlluvial deposits (Holocene)
    QoalQoal
    TfshBasalt of Sand Hollow (middle Miocene) - Frenchman Springs Member, Wanapum Basalt
    TfsfBasalt of Silver Falls (middle Miocene) - Frenchman Springs Member, Wanapum Basalt
    TgsbSentinel Bluffs member (middle Miocene) - Grande Ronde Basalt
    TgwwWinter Water member (middle Miocene) - Grande Ronde Basalt
    TgouOrtley and Umtanum members (middle Miocene) - Grande Ronde Basalt
    TsmScotts Mills Formation-undifferentiated (Oligocene to lower Miocene?) - Grande Ronde Basalt
    SLV_STX.AAT
    Linear structural features (Source: OFR-99-0141)
    LTYPE
    Line type (Source: OFR-99-0141)
    ValueDefinition
    cross-sectioncross-section line
    f.a., monocline, concealedMonocline fold-axis that is concealed and inferred
    f.a., monocline, concealedmMonocline fold-axis that is mainly(?) concealed
    f.a., monocline, inferredMonocline fold-axis whose position is inferred.
    f.a., monocline, inferredmMonocline fold-axis whose position is mainly(?) inferred.
    f.a., monocline, plungePlunging monocline fold-axis
    SCM_STX.PAT
    Information on a singular bedding type and position (Source: OFR-99-0141)
    PTTYPE
    Point type (Source: OFR-99-0141)
    ValueDefinition
    beddingbedding plane
    DIP
    Bedding Dip (Source: OFR-99-0141)
    ValueDefinition
    30Bedding plane has a dip of 30 degrees.
    STRIKE
    Bedding strike (Source: OFR-99-0141)
    ValueDefinition
    323Bedding plane has a strike of 323 degrees.
    SLV_NEAT.AAT
    Neatline for Silverton and Scotts Mills (Source: OFR-99-0141)
    LTYPE
    Line Type (Source: OFR-99-0141)
    ValueDefinition
    map boundaryoutline of mapped area around both Silverton and Scotts Mills quadrangles
    SLV_WELL.PAT
    well sample data (Source: OFR-99-0141)
    PTTYPE
    Point Type (Source: OFR-99-0141)
    ValueDefinition
    well locationLocation of sample well
    SAMPNO
    Sample number to identify well (Source: OFR-99-0141)
    ValueDefinition
    ?unknown sample number
    (blank)no well information
    Range of values
    Minimum:18259
    Maximum:50652
    TOB
    elevation relative to sea level to top of basalt in feet (Source: OFR-99-0141)
    Range of values
    Minimum:-529
    Maximum:+215
    Units:feet
    Resolution:1
    Entity_and_Attribute_Overview: 
    LINE TYPES

GEOLOGY - SLV_GEO:
contact, inferred
fault, concealed
map boundary
normal fault, concealed
normal fault, concealedm
normal fault, inferred
normal fault, inferredm

STRUCTURE - SLV_STX:
cross-section
f.a., monocline, concealed
f.a., monocline, concealedm
f.a., monocline, inferred
f.a., monocline, inferredm
f.a., monocline, plunge

NEAT - SLV_NEAT:
map boundary
    Entity_and_Attribute_Detail_Citation: More information can be found in the included readme file.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Terry Tolan
    • Marvin Beeson
    • Karen L. Wheeler
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Terry Tolan
    Portland State University
    Department of Geology, Portland State University
    Portland, Oregon
    USA

Why was the data set created?

This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report. The report does include, however, PostScript plot files containing images of two geologic map sheets with explanation, as well as the accompanying text describing the geology of the area.

How was the data set created?

  1. From what previous works were the data drawn?
    (source 1 of 1)
  2. How were the data generated, processed, and modified?
    (process 1 of 2)
    Digital compilation
    Several different coverages were generated during the construction of each of the three geologic quadrangle maps. Negatives of USGS topographic bases and geologic mylar tracings were scanned at 400 dpi, 1-bit TIFF bi-level compression type 1 (uncompressed) with rows per strip = 12000 on an ANATEK rasterizing scanner, then images were converted to ESRI ARC/INFO grids. The raster grids were converted to vector coverages with ARC/INFO's gridline routine. Alacarte and some custom menus and amls were used to project, transform, edit, tag and build, lines, polygons, and points in each map. A digital layout or map collar was made with Adobe Illustrator. The plot amls run in ARC/INFO and call the coverages, grids, and EPS to make uncompressed PostScript files. All maps are in UTM projection, zone 10, units meters, 1:24,000 scale. The pamphlet that describes the geology is saved to EPS from Microsoft Word.
    Base maps
    The source of the base maps used is the U.S. Geological Survey, 1:24,000 scale topographic maps, which have a 10-foot contour intervals (provisional edition, 1987). One base map layer for each of the three 7.5 minute quadrangles was prepared from negatives. Topographic bases for Scotts Mills, Silverton, and Stayton NE quadrangles were scanned on an Ideal rasterizing scanner at 400 dpi as 1-bit TIFF images. Scanned TIFF images of the bases were registered and rectified in ARC/INFO and then made into grids. The images were clipped using ARC/INFO grid to conform to the area of the geologic coverages and merged with the geology grid to give an apparent transparent color image of both combined. These base map-geology layers are digital images but no information other than location is attached to the lines. The base-geology maps are provided for reference only.
    Date: 24-Jul-2000 (process 2 of 2)
    Creation of original metadata record Person who carried out this activity:
    Jennifer Lenz
    US Geological Survey
    12201 Surise Valley Drive, Mail Stop 918
    Reston, VA
    USA

    703-648-6974 (voice)
    703-648-6560 (FAX)
    pschweitzer@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?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This digital database represents the general distribution of bedrock and surficial deposits of the Scotts Mills, Silverton, and Stayton NE 7.5 minute quadrangles along the eastern margin of the Willamette Valley and adjacent lower foothills (Waldo and Silverton Hills) of the Cascade Range. The major emphasis of this investigation was to identify and map Columbia River Basalt Group (CRBG) units within the Scotts Mills, Silverton, and Stayton NE quadrangles and to utilize this detailed CRBG stratigraphy to identify and characterize structural features.
  5. How consistent are the relationships among the observations, including topology?
    This digital map database was compiled from previously published and unpublished data and new mapping by the authors.

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: none
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Information Services
    Box 25248, Denver Federal Center
    Denver, CO
    USA

    1-888-ASK-USGS (voice)
    1-303-202-4693 (FAX)
    infoservices@usgs.gov
  2. What's the catalog number I need to order this data set? USGS OFR 99-141
  3. What legal disclaimers am I supposed to read?
    This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
    This database, identified as "Geologic Map of the Scotts Mills, Silverton, and Stayton Northeast 7.5 Minute Quadrangles: A Digital 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.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: geologic units, faults, and structural measurement points in format ARCE (version ARC/INFO version 7.2.1 for NT) Size: 10
      Network links: http://pubs.usgs.gov/of/1999/0141/sssofr.tar.gz
    • Cost to order the data: none

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 for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://geo-nsdi.er.usgs.gov/metadata/open-file/99-141/silverton.faq.html>
Generated by mp version 2.9.48 on Tue Jul 03 20:07:15 2018