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Preliminary Integrated Geologic Map Databases for the United States Central States: Montana, Wyoming, Colorado, New Mexico, Kansas, Oklahoma, Texas, Missouri, Arkansas, and Louisiana, North Dakota, South Dakota, Nebraska, and Iowa, - The State of Iowa

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Frequently anticipated questions:

What does this data set describe?

Title:
Preliminary Integrated Geologic Map Databases for the United States Central States: Montana, Wyoming, Colorado, New Mexico, Kansas, Oklahoma, Texas, Missouri, Arkansas, and Louisiana, North Dakota, South Dakota, Nebraska, and Iowa, - The State of Iowa
Abstract:
This open-file report presents the results of the USGS Mineral Resources Program activity to compile a national-scale geologic map database to support national and regional level projects, including mineral resource and geo- environmental assessments. The only comprehensive sources of regional- and national-scale geologic maps are state geologic maps with scales ranging from 1:100,000 to 1:1,000,000. Digital versions of these state maps form the core of what is presented here. Because no adequate geologic map exists for the state of Alaska, it is being compiled in regional blocks that also form part of this national database. It is expected that this series will completed by approximately the end of 2007. These maps and databases are being released in blocks of states or, in the case of Alaska, as compiled blocks of 1:250,000-scale quadrangles as chapters in this series. For Alaska, formal maps as well as databases are being published here, whereas for the conterminous U.S. only state databases and preview graphics are presented, because published maps for most states already exist. For Alaska these regional compilations will form the base for compiling a new geologic map of the state. As documented in Chapter A, standards for the conterminous U.S. are somewhat different than those for Alaska and Hawaii.
Supplemental_Information:
This database consists of five major Arc/Info GIS datasets for each state; - one: geologic map with formations, - two: faults (where present), - three: dikes (where present), - four: miscellaneous line features (where present), - five: miscellaneous point features (where present).

  1. How might this data set be cited?
    Stoeser, Douglas B., Green, Gregory N., Morath, Laurie C., Heran, William D., Wilson, Anna B., Moore, David W., and Bradley S. Van Gosen, 2006, Preliminary Integrated Geologic Map Databases for the United States Central States: Montana, Wyoming, Colorado, New Mexico, Kansas, Oklahoma, Texas, Missouri, Arkansas, and Louisiana, North Dakota, South Dakota, Nebraska, and Iowa, - The State of Iowa: U.S. Geological Survey Open-File Report 2005-1351, U.S. Geological Survey, Denver, CO.

    Online Links:

    This is part of the following larger work.

    Stoeser, Douglas B., Green, Gregory N., Stoeser, Douglas B., Green, Gregory N., Morath, Laurie C., Heran, William D., Wilson, Anna B., Moore, David W., and Bradley S. Van Gosen, 2006, Preliminary Integrated Geologic Map Databases for the United States Central States: Montana, Wyoming, Colorado, New Mexico, Kansas, Oklahoma, Texas, Missouri, Arkansas, and Louisiana, North Dakota, South Dakota, Nebraska, and Iowa.: U.S. Geological Survey Open-File Report 1351, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -96.7
    East_Bounding_Coordinate: -90.1
    North_Bounding_Coordinate: 43.6
    South_Bounding_Coordinate: 40.4
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2006
    Currentness_Reference:
    publication date
  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.
    2. What coordinate system is used to represent geographic features?
      The map projection used is Lambert Conformal Conic.
      Projection parameters:
      Standard_Parallel: 33
      Standard_Parallel: 45
      Longitude_of_Central_Meridian: -100.0
      Latitude_of_Projection_Origin: 0
      False_Easting: 0.00000
      False_Northing: 0.00000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.01
      Ordinates (y-coordinates) are specified to the nearest 0.01
      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 1/294.98.
  7. How does the data set describe geographic features?
    ia_geol.pat
    Polygon attribute table for the Iowa geologic coverage. (Source: ESRI)
    orig_label
    unmodified map unit symbol from source cover. (Source: Doug Stoeser)
    ValueDefinition
    KcdColorado and Dakota Groups
    KuCretaceous Undifferentiated
    JfdFt.Dodge Beds
    PAwWabaunsee Group
    PAsShawnee Group
    PAdDouglas Group
    PAlLansing Group
    PAkcKansas City Group
    PApPleasanton Group
    PAmMarmaton Group
    PAchCherokee Group
    MmMeramec Series
    MoOsage Series
    MkKinderhook Series
    DysYellow Spring Group
    DlcLime Creek Formation
    DsqState Quarry Limestone
    DsrShell Rock Formation
    DcvCedar Valley Limestone
    DwWapsipinicon Formation
    DlpLaPorte City Chert
    SnNiagaran Series
    SaAlexandrian Series
    OmMaquoketa Formation
    OgdpGalena-Decorah-Platteville Formations
    OspSt. Peter Sandstone
    OpcPrairie du Chien Formation
    CAscSt. Croixan Series
    pCAcCrystalline Rocks
    pCAsSioux Quartzite
    waterSurface Water
    sgmc_label
    sgmc_label = orig_label + ;n where n= province number (n=0 if no province) (Source: Doug Stoeser)
    unit_link
    composite map label = ST + sgmc_label This creates a unique identifier for every unit in the CONUS (continental United States) covers. (Source: Doug Stoeser)
    source
    reference to the source used (Source: Doug Stoeser)
    ValueDefinition
    IA001 
    unit_age
    The geologic age from the source map used. (Source: Doug Stoeser)
    ValueDefinition
    Cretaceousgeologic age
    Jurassicgeologic age
    Late Pennsylvaniangeologic age
    Middle Pennsylvaniangeologic age
    Late Mississippiangeologic age
    Early Mississippiangeologic age
    Late Devoniangeologic age
    Middle Devoniangeologic age
    Early Devoniangeologic age
    Middle Siluriangeologic age
    Early Siluriangeologic age
    Late Ordoviciangeologic age
    Middle Ordoviciangeologic age
    Early Ordoviciangeologic age
    Late Cambriangeologic age
    Middle Proterozoicgeologic age
    rocktype1
    The predominant lithology found in the formation. (Source: unit classification)
    ValueDefinition
    chert 
    gypsum 
    shale 
    sandstone 
    limestone 
    dolostone 
    granite 
    water 
    rocktype2
    The second most predominant lithology in the formation. (Source: unit classification)
    ValueDefinition
    chert 
    shale 
    claystone 
    siltstone 
    sandstone 
    limestone 
    dolostone 
    gneiss 
    ia_geol.aat
    Arc attribute table for Iowa geologic coverage. (Source: ESRI)
    arc-code
    Unique identifier for the line feature (Source: AAT data dictionary, Appendix H)
    ValueDefinition
    1contact, location certain
    7shoreline or riverbank
    124state boundary
    arc-para1
    Used for "decorated" lines where additional information is needed. (Source: AAT data dictionary)
    ValueDefinition
    0no additional information
    1for normal faults, upthrown side is to the right
    arc-para2
    "Scratch" field used mostly in Alaska. (Source: AAT data dictionary)
    ValueDefinition
    0no additional information
    source
    A coded reference citation indicating source material used. (Source: AAT data dictionary)
    ValueDefinition
    IA001 
    US001 
    Entity_and_Attribute_Overview:
    Coding for polygon attributes:

    NAME: FEATURE: orig_label unmodified map unit symbols from source cover sgmc_label orig_label modified for standard geologic age symbols and an integer code added for province unit_link sgmc_label and a state code identifier source reference to source of data unit_age geologic age rocktype1 predominant lithology rocktype2 second most predominant lithology

    Coding for arc attributes:

    NAME: FEATURE: arc-code unique integer identifier arc-para1 used where additional information is needed arc-para2 scratch field source reference to source of data

    Coding for point attributes:

    NAME: FEATURE: point_feature name of feature on map source reference to source of data

    Coding for dikes (special arcs) attributes:

    NAME: FEATURE: orig_label unmodified map unit symbols from source cover sgmc_label orig_label modified for standard geologic age symbols and an integer code added for province arc-code unique integer identifier dike_lith general lithology dike_age geologic age source reference to source of data

    Entity_and_Attribute_Detail_Citation: ESRI

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Douglas B. Stoeser
    • Gregory N. Green
    • Laurie C. Morath
    • William D. Heran
    • Anna B. Wilson
    • David W. Moore
    • Bradley S. Van Gosen
  2. Who also contributed to the data set?
    State Geologic Map Compilation (SGMC) activity of the National Surveys and Analysis projects of the US Geological Survey Mineral Resources Program.

  3. To whom should users address questions about the data?
    Gregory N. Green
    U.S. Geological Survey
    MS 973, USGS, Denver Federal Center
    Denver, CO
    USA

    303-236-5390 (voice)
    ggreen@usgs.gov

Why was the data set created?

A primary goal of this work is to develop geologic map datasets with standardized structure and attribution. The database design and standards are documented in Chapter A of this series. The intent is that contiguous databases can be merged seamlessly and without any additional effort. In addition to a common database structure, the conterminous U.S. state databases (the contiguous 48 states) have been fitted to a set of standard state boundaries so that, when states are merged, they match without slivers or overlap. No attempt has been made to reconcile differences in mapping across state boundaries.

How was the data set created?

  1. From what previous works were the data drawn?
    IA001 (source 1 of 3)
    Iowa Department of Natural Resources - Geological Survey, 1969, Geologic map of Iowa: Statewide Digital Data Bases Bedrock Geology, Iowa Department of Natural Resources, Iowa City, Iowa, USA.

    Online Links:

    Type_of_Source_Media: online
    Source_Scale_Denominator: 500000
    Source_Contribution:
    A digital representation of the Bedrock Geological map of Iowa

    US001 (source 2 of 3)
    Johnson, Bruce R., unpublished material, 1:100,000 Scale State Boundaries of the Conterminous United States.

    Type_of_Source_Media: online
    Source_Scale_Denominator: 100,000
    Source_Contribution: Provided linework for state boundaries
    Johnson Lith Class 6.1 (source 3 of 3)
    Johnson, Bruce R., unpublished material, Geologic Map Unit Classification, ver. 6.1.

    Type_of_Source_Media: online; http://geology.usgs.gov/dm
    Source_Contribution: Classification scheme used for lithology.
  2. How were the data generated, processed, and modified?
    Date: 2003 (process 1 of 6)
    The purpose of this standardization is to allow all SGMC covers to be seamlessly joined without any additional effort to form regional or national level digital maps. Note that for Alaska, the state is being compiled as blocks of 1:250k quadrangles that will ultimately be used to compile a new state map. Douglas Stoeser and Ric Wilson are co-coordinators for the overall SGMC effort, with Stoeser coordinating work on the mainland states and Wilson coordinating work for Alaska and Hawaii.
    Date: Feb-2005 (process 2 of 6)
    G.N. Green obtained the digital geologic map of Iowa from the website: ftp://ftp.igsb.uiowa.edu/gis_library/IA_state/Geologic/Bedrock/ Bedrock_geology.zip. Re-projected the coverage into the following:

    projection: Lambert Conformal Conic units: meters datum: NAD27 standard parallel 1: 33 0 0.000 standard parallel 2: 45 0 0.000 central meridian: -100 0 0.000 reference latitude: 0 0 0.000 false easting: 0.000 false northing: 0.000

    All attributes were deleted except MAPNAME.

    (Note: Attributes associated with the generation of the coverages were not deleted. PAT - shape, area, perimeter, coverage#, and coverage-id AAT - shape, fnode#, tnode#, lnode#, rnode#, length, coverage#, and coverage- id)

    The values from MAPNAME where then calculated into a new field called ORIG_LABEL.
    Date: 04-Apr-2004 (process 3 of 6)
    The following attributes were exported from Filemaker as a comma delimited file

    map_symbol1 map_symbol2 unit_link reference_id unit_age rocktype1 rocktype2

    The attributes were then loaded into INFO with the following structures:

    item name: orig_label width: 12 output: 12 type: c

    item name: sgmc_label width: 16 output: 16 type: c

    item name: unit_link width: 18 output: 18 type: c

    item name: source width: 6 output: 8 type: c

    item name: unit_age width: 60 output: 60 type: c

    item name: rocktype1 width: 40 output: 40 type: c

    item name: rocktype2 width: 40 output: 40 type: c
    Date: Jan-2005 (process 4 of 6)
    Once the .csv was loaded, it was joined in Arc/Info with the joinitem command. orig_label as the related item.
    Date: Mar-2005 (process 5 of 6)
    Once the .pat file was correct, the .aat file was addressed. The following items were added to the table:

    item name: arc-code width: 3 output: 3 type: i

    item name: arc-para1 width: 3 output: 3 type: i

    item name: arc-para2 width: 3 output: 3 type: i

    item name: source width: 6 output: 8 type: c

    Date: Mar-2005 (process 6 of 6)
    Arc-code was populated using the digital map source to tag the lines using the AAT line type data dictionary. Arc-para1 was populated when additional information was available such as upthrown side of a fault or angle of thrusting on a fault. Arc-para2 is a scratch field that is used mostly in Alaska. Source was populated with code that designates the source used for the linework; typically the paper map.
  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 values of the attributes ROCKTYPE1 and ROCKTYPE2 were assigned based on the information in the legends of the source maps (most of which are paper). The definitions of these values are described in the draft document Geologic Map Unit Classification version 6.1 (Johnson and others, 2002; available at the following website: http://geology.usgs.gov/dm).
  2. How accurate are the geographic locations?
    The geologic map was digitized from compilations ranging in scale from 1:1,000,000 to 1:100,000 and is an accurate representation of the source maps. It is intended to be used at scales ranging from 1:1,000,000 to 1:500,000. Display at significantly larger scales may produce small errors in locations of contacts or faults relative to features contained in other data sets. Accuracy of Iowa state boundary and those arcs intersecting it: The accuracy of the state boundary arcs is based on the 1:100000 scale original data used to produce this boundary (Johnson, Bruce R. and Leveritch, Beth, 1998, 1:100,000 Scale State Boundaries of the Conterminous United States: U.S. Geological Survey, unpublished (see metadata file: st100kmeta.txt, Chapter A). Those internal arcs intersecting the state boundary were extended or shortened as needed to complete polygons, possibly creating a small amount of error.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Bodies of water are classified as water, and the geologic units underlying them are not included in this coverage.
  5. How consistent are the relationships among the observations, including topology?
    All internal polygons were checked for closure with vendor software and on hard copy plots. Overshoots and undershoots have been deleted or corrected as appropriate.

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 database is not meant to be used or displayed at any scale other than 1:500,000.

Any hardcopies utilizing these data sets shall clearly indicate their source. If the licensee has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. Licensee specifically agrees not to misrepresent these data sets, nor to imply that changes they made were approved by the U.S. Geological Survey.

  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Information Services
    U.S. Geological Survey
    507 National Center
    Reston, Virginia
    USA

    1-888-ASK-USGS or 1-703-648-5953 (voice)
  2. What's the catalog number I need to order this data set? USGS OFR 2005-1351
  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 (USGS) editorial standard nor with the North American stratigraphic codes. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the USGS. Although these data have been used by the USGS and have been successfully imported into data base programs, no warranty, expressed or implied, is made by the USGS as to how successfully or accurately the data can be imported into any specific application software running on any specific hardware platform. The fact of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith. This data base GIS is not meant to be used or displayed at any scale other than 1:500,000.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: Geologic units and structural features in format ARC/INFO export (version 9.1)
      Network links: http://pubs.usgs.gov/of/2005/1351/
    • Cost to order the data: none

Who wrote the metadata?

Dates:
Last modified: Feb-2005
Metadata author:
U.S. Geological Survey
Attn: Gregory N. Green
MS 973, USGS, Denver Federal Center
Denver, CO
USA

1-303-236-5390 (voice)
ggreen@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://mrdata.usgs.gov/geology/state/metadata/ia.faq.html>
Generated by mp version 2.9.50 on Mon Jan 27 16:07:32 2020