1. Mineral Resources
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The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  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?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Horton, John D., 20170818, The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States: U.S. Geological Survey data release DOI: 10.5066/F7WH2N65, U.S. Geological Survey, Denver, CO.

   Online Links:

   • https://doi.org/10.5066/F7WH2N65

   This is part of the following larger work.
   Horton, John D., San Juan, Carma A., and Stoeser, Douglas B., 20170818, The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States: U.S. Geological Survey data series DS 1052, U.S. Geological Survey, Denver, CO.

   Online Links:

   • https://doi.org/10.3133/ds1052

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -129.567628731
   East_Bounding_Coordinate: -64.982027108
   North_Bounding_Coordinate: 50.784681301
   South_Bounding_Coordinate: 22.397057591
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 1961

   Ending_Date: 2012

   Currentness_Reference:

   State map publication dates.

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon, Polyline, Point)
   

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):
      • G-polygon (313732)
      • Link (339582)
      • Entity point (4019)
   2. What coordinate system is used to represent geographic features?
      The map projection used is USA Contiguous Albers Equal Area Conic USGS version (ESRI Full Name: USA_Contiguous_Albers_Equal_Area_Conic_USGS_version).
      

      Projection parameters:

      Standard_Parallel: 29.5
      Standard_Parallel: 45.5
      Longitude_of_Central_Meridian: -96.0
      Latitude_of_Projection_Origin: 23.0
      False_Easting: 0.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      
7. How does the data set describe geographic features?

   SGMC_Geology (polygon) attribute table

   Table containing attribute information associated with the polygon data set. (Source: USGS)

   OBJECTID

   Unique internal feature number managed by Esri. (Source: Esri)

   Range of values
   Minimum:	1
   Maximum:	313732
   Units:	sequential integers

   SHAPE

   Internal feature geometry managed by Esri. (Source: Esri) geometry:Polygon

   STATE

   State abbreviation (Source: US Postal Service)

   Formal codeset
   Codeset Name:	US Postal 2-Letter State
   Codeset Source:	US Census/US Postal Service; also appendix 9 of the data series report.

   ORIG_LABEL

   Original map unit label. (Source: State geologic maps) Map unit label (symbol) from the original source digital map.

   SGMC_LABEL

   The SGMC map unit label. (Source: USGS) Original map unit symbol as given on the source map. However, the age portion of the map unit symbol was coded using appendix 7 of the data series report rather than using any special characters that may have been used in the original source data. The symbol may differ from the original source map if that label was determined incorrect after comparing it to the printed map or other references.

   UNIT_LINK

   Unique value used as the key field for the entire database. (Source: USGS) Unique value generated by combining the fields: STATE, SGMC_LABEL, and the PROV_NO from the Units table. The purpose of this field is to create a unique value for every unit in the database. It is the linking field (key field) between all the attribute tables.

   UNIT_NAME

   Map unit name. (Source: State geologic maps) The name of the map unit as given on the source map.

   AGE_MIN

   Minimum age of unit (FULL_MIN field from the Age table). (Source: 2016 International Chronostratigraphic Chart (v2016/04)) Youngest geochronologic unit age. See appendix 3 of the data series report for a complete list of all available entries.

   AGE_MAX

   Maximum age of unit (FULL_MAX field from the Age table). (Source: 2016 International Chronostratigraphic Chart (v2016/04)) Oldest geochronologic unit age. See appendix 3 of the data series report for a complete list of all available entries.

   MAJOR1

   Any lithology ranked by the SGMC compiler as a major component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as major. Note that the fields MAJOR1 thru MAJOR3 only indicate that the lithology is considered a major portion of the entire geologic unit as determined by the SGMC compiler; i.e. MAJOR1 is not considered more major than MAJOR2 or MAJOR3. All the MAJOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of available entries.

   MAJOR2

   Any lithology ranked by the SGMC compiler as a major component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as major. Note that the fields MAJOR1 thru MAJOR3 only indicate that the lithology is considered a major portion of the entire geologic unit as determined by the SGMC compiler; i.e. MAJOR1 is not considered more major than MAJOR2 or MAJOR3. All the MAJOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of available entries.

   MAJOR3

   Any lithology ranked by the SGMC compiler as a major component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as major. Note that the fields MAJOR1 thru MAJOR3 only indicate that the lithology is considered a major portion of the entire geologic unit as determined by the SGMC compiler; i.e. MAJOR1 is not considered more major than MAJOR2 or MAJOR3. All the MAJOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of available entries.

   MINOR1

   Any lithology ranked by the SGMC compiler as a minor component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as minor. Note that the fields MINOR1 thru MINOR5 only indicate that the lithology is considered a minor portion of the entire geologic unit as determined by the SGMC compiler; i.e. MINOR1 is not considered more minor than MINOR2-5. All the MINOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of all available entries.

   MINOR2

   Any lithology ranked by the SGMC compiler as a minor component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as minor. Note that the fields MINOR1 thru MINOR5 only indicate that the lithology is considered a minor portion of the entire geologic unit as determined by the SGMC compiler; i.e. MINOR1 is not considered more minor than MINOR2-5. All the MINOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of all available entries.

   MINOR3

   Any lithology ranked by the SGMC compiler as a minor component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as minor. Note that the fields MINOR1 thru MINOR5 only indicate that the lithology is considered a minor portion of the entire geologic unit as determined by the SGMC compiler; i.e. MINOR1 is not considered more minor than MINOR2-5. All the MINOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of all available entries.

   MINOR4

   Any lithology ranked by the SGMC compiler as a minor component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as minor. Note that the fields MINOR1 thru MINOR5 only indicate that the lithology is considered a minor portion of the entire geologic unit as determined by the SGMC compiler; i.e. MINOR1 is not considered more minor than MINOR2-5. All the MINOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of all available entries.

   MINOR5

   Any lithology ranked by the SGMC compiler as a minor component of the geologic unit. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as minor. Note that the fields MINOR1 thru MINOR5 only indicate that the lithology is considered a minor portion of the entire geologic unit as determined by the SGMC compiler; i.e. MINOR1 is not considered more minor than MINOR2-5. All the MINOR fields are considered volumetrically equal. See appendix 4 of the data series report for the complete list of all available entries.

   INCIDENTAL

   Any lithology ranked by the SGMC compiler as an incidental component of the geologic unit. This field concatenates all incidental-ranked lithologies. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as incidental by the SGMC compiler. See appendix 4 of the data series report for the complete list of all available entries.

   INDETERMINATE

   Any lithology ranked by the SGMC compiler as a indeterminate component of the geologic unit. This field concatenates all indeterminate-ranked lithologies. Copied from the Lithology table. (Source: USGS) The lithology of the geologic unit ranked as indeterminate (information does not allow ranking) by the SGMC compiler. See appendix 4 of the data series report for the complete list of all available entries.

   REF_ID

   Unique reference value. (Source: USGS) Unique value representing the original digital source of the geologic polygons (REF_ID from the Reference table).

   REFERENCE

   The reference citation associated with the REF_ID value (from the Reference table). (Source: USGS) The reference citation for the source of the digital polygons. This could be a state map reference or an SGMC coder reference. See appendix 1 of the data series report for a complete list of state geologic maps used as the sources in this dataset.

   GENERALIZED_LITH

   The generalized lithology of the unit using the MAJOR1-3 and INDETERMINATE fields. (Source: USGS) This field represents an attempt by the authors to generalize all the major or indeterminate ranked lithologies for the geologic unit. See appendix 8 of the data series report for the complete list of available entries.

   DIGITAL_URL

   URL (Uniform Resource Locator) web link address from which the original digital data of the geologic map can be downloaded or viewed if available. (Source: USGS) Unique value for the URL web address of the original digital data of the geologic map if available.

   NGMDB1

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available. (Source: USGS) Unique value for the USGS National Geologic Map Database URL web address of the printed paper geologic map if available.

   NGMDB2

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available (if applicable). (Source: USGS) Unique value for the USGS National Geologic Map Database URL web address of the printed paper geologic map if available.

   NGMDB3

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available (if applicable). (Source: USGS) Unique value for the USGS National Geologic Map Database URL web address of the printed paper geologic map if available.

   Shape_Length

   Length of feature in internal units. (Source: Esri)

   Range of values
   Minimum:	20.187956
   Maximum:	49579919.420823
   Units:	meters

   Shape_Area

   Area of feature in internal units squared. (Source: Esri)

   Range of values
   Minimum:	8.987412
   Maximum:	221733225449.66638
   Units:	square meters

   RuleID

   Internal unit number used for geodatabase representation symbology. Representation based on the GENERALIZED_LITH field. (Source: Esri)

   Range of values
   Minimum:	1
   Maximum:	33
   Units:	Unknown

   Override

   Override field used by geodatabase representation symbology. (Source: Esri) Unknown Blob data type

   SGMC_Points attribute table

   Table containing attribute information associated with the points data set. (Source: USGS)

   OBJECTID

   Unique internal feature number managed by Esri. (Source: Esri)

   Range of values
   Minimum:	1
   Maximum:	4019
   Units:	sequential integers

   SHAPE

   Internal feature geometry managed by Esri. (Source: Esri) geometry:Point

   STATE

   State abbreviation (Source: US Postal Service)

   Formal codeset
   Codeset Name:	US Postal 2-Letter State
   Codeset Source:	US Census/US Postal Service; also appendix 9 of the data series report.

   DESCRIPTION

   Free-form field for the descriptions of the points from the original state source digital files. No standardization applied. (Source: State geologic maps) Unique description values from the original source data.

   REF_ID

   Unique reference value. (Source: USGS) Unique value representing the original digital source of the points (REF_ID from the Reference table).

   REFERENCE

   The reference citation associated with the REF_ID value (from the Reference table). (Source: USGS) The reference citation for the original state data source. See appendix 1 of the data series report for a complete list of state geologic maps used as the sources in this dataset.

   DIGITAL_URL

   URL (Uniform Resource Locator) web link address from which the original digital data of the geologic map can be downloaded or viewed if available. (Source: USGS) Unique value for the URL web address of the original digital data of the geologic map if available.

   NGMDB

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available. (Source: USGS) Unique value for the USGS National Geologic Map Database URL web address of the printed paper geologic map if available.

   SGMC_Structure (polyline) attribute table

   Table containing attribute information associated with the polyline data set. (Source: USGS)

   OBJECTID

   Unique internal feature number managed by Esri. (Source: Esri)

   Range of values
   Minimum:	1
   Maximum:	339582
   Units:	sequential integers

   SHAPE

   Internal feature geometry managed by Esri. (Source: Esri) geometry:Polyline

   STATE

   State abbreviation (Source: US Postal Service)

   Formal codeset
   Codeset Name:	US Postal 2-Letter State
   Codeset Source:	US Census/US Postal Service; also appendix 9 of the data series report.

   DESCRIPTION

   A description used by SGMC to classify the different structural line types. (Source: USGS) See appendix 5 of the data series report for a complete list of available entries.

   MISC

   Free-form field used for any additional descriptive terms from the original state source files. (Source: State geologic maps) Unknown

   REF_ID

   Unique reference value. (Source: USGS) Unique value representing the original digital source of the lines (REF_ID from the Reference table).

   REFERENCE

   The reference citation associated with the REF_ID value (from the Reference table). (Source: USGS) The reference citation for the original state data or SGMC coder source. See appendix 1 of the data series report for a complete list of state geologic maps used as the sources in this dataset.

   DIGITAL_URL

   URL (Uniform Resource Locator) web link address from which the original digital data of the geologic map can be downloaded or viewed if available. (Source: USGS) Unique value for the URL web address of the original digital data of the geologic map if available.

   NGMDB1

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available. (Source: USGS) Unique value for the URL web address of the printed paper geologic map.

   NGMDB2

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available (if applicable). (Source: USGS) Unique value for the URL web address of the printed paper geologic map.

   NGMDB3

   USGS National Geologic Map Database URL (Uniform Resource Locator) web link address from which the paper version of the geologic map can be viewed or ordered if available (if applicable). (Source: USGS) Unique value for the URL web address of the printed paper geologic map.

   Shape_Length

   Length of feature in internal units. (Source: Esri)

   Range of values
   Minimum:	0.092922
   Maximum:	297069.549889
   Units:	Meters

   RuleID

   Internal unit number used for geodatabase representation symbology. Representation based on the DESCRIPTION field. (Source: Esri)

   Range of values
   Minimum:	1
   Maximum:	66
   Units:	Unknown

   Override

   Override field used by geodatabase representation symbology. (Source: Esri) Unknown Blob data type

   Entity_and_Attribute_Overview:

   The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields and (or) table entries of the data set.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Horton, John D.
2. Who also contributed to the data set?

   The State Geologic Map Compilation of the Conterminous United States was developed by the U.S. Geological Survey Mineral Resources Program (MRP). The project owes its success to numerous MRP staff who compiled the Preliminary Integrated Geologic Map Databases for the United States (PIGMD) as well as the foundational geologic mapping work completed by U.S. State Geologic Surveys and academia.

3. To whom should users address questions about the data?
   John D. Horton

   U.S. Geological Survey, Southwest Region

   Physical Scientist

   Denver Federal Center, PO Box 25046, MS-973

   Denver, CO
   

   303-236-1921 (voice)

   303-236-3200 (FAX)

   jhorton@usgs.gov

Why was the data set created?

The purposes of these data are to provide a standardized, vector-based, state geologic map database of the conterminous U.S. at an approximate scale of 1:1,000,000. The compilation includes new geologic information and state maps, corrections to the original Preliminary Integrated Geologic Map Databases for the United States (PIGMD), and enhancements which are explained in the accompanying report. The data are suitable for use in Geographic Information Systems (GIS) or other database and geospatial software used to derive maps and perform geospatial analyses. The information is intended to meet the needs of a wide community of users that extends from geosciences to State and Federal agencies, private industry, and the general public.

How was the data set created?

1. From what previous works were the data drawn?

   Preliminary integrated geologic map databases for the United States - Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina (source 1 of 20)

   Dicken, C.L., Nicholson, S.W., Horton, J.D., Foose, M.P., and Mueller, J.A.L., 2007, Preliminary integrated geologic map databases for the United States - Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2005/1323

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   State geologic map data for Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina.

   Preliminary integrated geologic map databases for the United States - Delaware, Maryland, New York, Pennsylvania, and Virginia (source 2 of 20)

   Dicken, C.L., Nicholson, S.W., Horton, J.D., Kinney, S.A., Gunther, G., Foose, M.P., and Mueller, J.A.L., 2008, Preliminary integrated geologic map databases for the United States - Delaware, Maryland, New York, Pennsylvania, and Virginia: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2005/1325

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   State geologic map data for Delaware, Maryland, New York, Pennsylvania, and Virginia.

   Preliminary integrated geologic map databases for the United States - Western States: California, Nevada, Arizona, Washington, Oregon, Idaho and Utah (source 3 of 20)

   Ludington, S., Moring, B.C., Miller, R.J., Stone, P.A., Bookstrom, A.A., Bedford, D.R., Evans, J.G., Haxel, G.A., Nutt, C.J., Flyn, K.S., and Hopkins, M.J., 2007, Preliminary integrated geologic map databases for the United States - Western States: California, Nevada, Arizona, Washington, Oregon, Idaho and Utah: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2005/1305/

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   State geologic map data for California, Arizona, Washington, Oregon, and Utah.

   Preliminary integrated geologic map databases for the United States - Minnesota, Wisconsin, Michigan, Illinois, and Indiana (source 4 of 20)

   Nicholson, S.W., Dicken, C.L., Foose, M.P., Mueller, J.A.L., 2007, Preliminary integrated geologic map databases for the United States - Minnesota, Wisconsin, Michigan, Illinois, and Indiana: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2004/1355

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution: State geologic map data for Wisconsin, Michigan, and Indiana.
   

   Preliminary integrated geologic map databases for the United States - Kentucky, Ohio, Tennessee, and West Virginia (source 5 of 20)

   Nicholson, S.W., Dicken, C.L., Horton, J.D., Labay, K.A., Foose, M.P., and Mueller, J.A.L., 2007, Preliminary integrated geologic map databases for the United States - Kentucky, Ohio, Tennessee, and West Virginia: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2005/1324

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   State geologic map data for Kentucky, Ohio, Tennessee, and West Virginia.

   Preliminary integrated geologic map databases for the United States - Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island and Vermont (source 6 of 20)

   Nicholson, S.W., Dicken, C.L., Horton, J.D., Foose, M.P., Mueller, J.A.L., and Hon, R., 2007, Preliminary integrated geologic map databases for the United States - Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island and Vermont: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2006/1272

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   State geologic map data for Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, and Rhode Island.

   Preliminary integrated geologic map databases for the United States - Central States: Montana, Wyoming, Colorado, New Mexico, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, Texas, Iowa, Missouri, Arkansas, and Louisiana (source 7 of 20)

   Stoeser, D.B., Green, G.N., Morath, L.C., Heran, W.D., Wilson, A.B., Moore, D.W., and Van Gosen, B.S., 2007, Preliminary integrated geologic map databases for the United States - Central States: Montana, Wyoming, Colorado, New Mexico, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, Texas, Iowa, Missouri, Arkansas, and Louisiana: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/of/2005/1351

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Contribution:

   State geologic map data for Wyoming, Colorado, New Mexico, part of South Dakota, Nebraska, Kansas, Oklahoma, Texas, Missouri, Arkansas, and Louisiana.

   Geologic Map of Idaho (source 8 of 20)

   Lewis, R.S., Link, P.K., Stanford, L.R., and Long, S.P., 2012, Geologic Map of Idaho, Geologic Map 9: Idaho Geological Survey, Idaho Geological Survey.

   Online Links:

   • http://www.idahogeology.org/Products/reverselook.asp?switch=title&value=Geologic_Map_of_Idaho

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 750000
   Source_Contribution: State geologic map data for Idaho.
   

   Bedrock Geology of Illinois (source 9 of 20)

   Kolata, D.R., 2005, Bedrock Geology of Illinois, Map Series 14: Illinois State Geological Survey, Illinois State Geological Survey.

   Online Links:

   • https://clearinghouse.isgs.illinois.edu/data/geology/bedrock-geology-2005

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 500000
   Source_Contribution: State geologic map data for Illinois.
   

   Bedrock Geologic Map of Iowa (source 10 of 20)

   Witzke, B.J., Anderson, R.R., and Pope, J.P., 2010, Bedrock Geologic Map of Iowa, Open-File Map 2010-01: Iowa Geological and Water Survey, DNR, Iowa Geological and Water Survey, DNR.

   Online Links:

   • ftp://ftp.igsb.uiowa.edu/gis_library/IA_state/Geologic/Bedrock/Bedrock_Geologic_Map.zip

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 500000
   Source_Contribution: State geologic map data for Iowa.
   

   Geologic Map of Minnesota-Bedrock Geology (source 11 of 20)

   Jirsa, M.A., Boerboom, T.J., Chandler, V.W., Mossler, J.H., Runkel, A.C., and Setterholm, D.R., 2011, Geologic Map of Minnesota-Bedrock Geology, S-21: Minnesota Geological Survey, Minnesota Geological Survey.

   Online Links:

   • http://conservancy.umn.edu/handle/11299/101466

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 500000
   Source_Contribution: State geologic map data for Minnesota.
   

   Geologic Map of Montana (source 12 of 20)

   Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A., 2007, Geologic Map of Montana, Geologic Map 62-C: Montana Bureau of Mines and Geology, Montana Bureau of Mines and Geology.

   Online Links:

   • http://www.mbmg.mtech.edu/mbmgcat/public/ListCitation.asp?pub_id=30080&

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 500000
   Source_Contribution:

   State geologic map data for Montana. This map was digitized in 2012 as a result of an agreement between USGS and the Montana Bureau of Mines and Geology.

   Geologic Map of Nevada (source 13 of 20)

   Crafford, A.E.J., 2007, Geologic map of Nevada: U.S. Geological Survey Data Series 249: USGS, USGS.

   Online Links:

   • https://pubs.usgs.gov/ds/2007/249/

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 250000
   Source_Contribution: State geologic map data for Nevada.
   

   Bedrock geologic map of Vermont (source 14 of 20)

   Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Series Map 3184: USGS, USGS.

   Online Links:

   • http://dec.vermont.gov/geological-survey/publication-gis/VTrock

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 100000
   Source_Contribution: State geologic map data for Vermont.
   

   Geologic Bedrock Map of North Dakota (source 15 of 20)

   North Dakota Geological Survey and North Dakota Department of Health, 2001, NDHUB.GeologyBedrock, Geologic bedrock map of North Dakota, digital version of Bluemle, John P., 1983, Geologic and topographic bedrock map of North Dakota: North Dakota Geological Survey, North Dakota Geological Survey.

   Online Links:

   • https://gishubdata.nd.gov/dataset/bedrock-geology

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 670000
   Source_Contribution: State geologic map data for North Dakota.
   

   Bedrock Geologic Map Showing Configuration of the Bedrock Surface in South Dakota East of the Missouri River (source 16 of 20)

   Tomhave, D.W., and Schulz, L.D., 2004, Bedrock geologic map showing configuration of the bedrock surface in South Dakota east of the Missouri River: South Dakota Geological Survey G-09: South Dakota Geological Survey, South Dakota Geological Survey.

   Online Links:

   • http://www.sdgs.usd.edu/pubs/other/esdbedrock_20040630.zip

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 5000000
   Source_Contribution:

   State geologic map data for bedrock in South Dakota; East of the Missouri River.

   Geologic map of New Mexico (source 17 of 20)

   New Mexico Bureau of Geology and Mineral Resources, 2003, Geologic map of New Mexico: New Mexico Bureau of Geology and Mineral Resources, New Mexico Bureau of Geology and Mineral Resources.

   Online Links:

   • https://geoinfo.nmt.edu/publications/maps/geologic/state/home.cfml

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 500000
   Source_Contribution:

   Portions of the state geologic map of New Mexico (Green and others, 1997) have been updated from this 2003 paper map.

   Bedrock Geology of Indiana (source 18 of 20)

   Survey, Indiana Geological, 2011, Bedrock geologic map of Indiana: Indiana Geological Survey Miscellaneous Map 48: Indiana Geological Survey, Indiana Geological Survey.

   Online Links:

   • http://maps.indiana.edu/download/Geology/Bedrock_Geology.zip

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 500000
   Source_Contribution:

   Minor updates added to the Indiana geologic data from this 2011 digital version.

   Geology - North Carolina (1:250,000) (source 19 of 20)

   The North Carolina Dept. of Environment, Health, and Natural Resources, Division of Land Resources, NC Geological Survey, in cooperation with the NC Center for Geographic Information and Analysis, 2007, Geology - North Carolina (1:250,000): NC Center for Geographic Information and Analysis, NC Center for Geographic Information and Analysis.

   Online Links:

   • http://data.nconemap.com/geoportal/catalog/search/resource/details.page?uuid=%7BA19C03CA-6A47-4617-B9BB-F225BAEB0E51%7D

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 250000
   Source_Contribution:

   Newly updated data for North Carolina (geology, faults and dikes) in 2007.

   Geologic map of California (source 20 of 20)

   Jennings, C.W., with modifications by Gutierrez, C., Bryant, W., Saucedo, G., and Wills, C., 2010, Geologic map of California, Version 2.0 (California Geological Survey 150th Anniversary Edition): California Geologic Data Map Series, GDM No. 2: Department of Conservation, California Geological Survey, Department of Conservation, California Geological Survey.

   Online Links:

   • ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Published_GIS_Data/GDM_002_GMC_750k_v2/GDM_002_GMC_750k_v2_GIS.zip

   Type_of_Source_Media: Digital and/or Hardcopy Resources
   Source_Scale_Denominator: 750000
   Source_Contribution:

   Newly updated data for California (geology, structure and points).

2. How were the data generated, processed, and modified?

   Date: 2016 (process 1 of 2)

   The 48 separate databases forming the Preliminary Integrated Geologic Map Databases for the United States (PIGMD) were integrated into a single ArcGIS 10 file geodatabase. Outdated state maps were replaced with newer state geologic maps or geologic information where available. All data were compared to published state geologic maps to ensure spatial integrity and data were fitted to a USGS national-scale state boundary. Attributes in the original state geologic map databases were standardized to conform to the USGS SGMC format (see the accompanying data series report for details). Errors, primarily in the coding of attributes, were corrected when reported or encountered. Where appropriate, supporting tables were updated to reflect current USGS nomenclature and linkages between tables were checked.

   Date: 01-Aug-2017 (process 2 of 2)

   Version 1.1: California - replaced the original digital data (Saucedo, George J., Bedford, David R., Raines, Gary L., Miller, Robert J., and Wentworth, Carl M., GIS Data for the Geologic Map of California, California Geological Survey, CD 2000-07) with the newer version (Jennings, C.W., with modifications by Gutierrez, C., Bryant, W., Saucedo, G., and Wills, C., 2010, Geologic map of California, Version 2.0 (California Geological Survey 150th Anniversary Edition), Department of Conservation, California Geological Survey: California Geologic Data Map Series, GDM No. 2, scale 1:750,000.). The newer 2010 California data contains corrections of spatial errors of up to 1km in the older dataset and updated fault, and point features. See the original source metadata of California for more information.

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?
   Frequency and summary statistics were performed on applicable fields to standardize entries according to SGMC appendices available in the accompanying data series report.
2. How accurate are the geographic locations?
   Accuracy is dependent on the source data and varies from state to state. See original source references of each state for more information (appendix 1 of report).
3. How accurate are the heights or depths?
   Vertical positional information is not applicable.
4. Where are the gaps in the data? What is missing?
   The data set is considered complete for the information presented and as described in the abstract. Users are advised to read the accompanying report and this metadata document carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Data were compared to referenced data sources to ensure consistency. Data were fitted to national-scale state boundaries. Topologic rules were used to eliminate polygonal gaps or overlaps.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None. Please refer to 'Distribution Info' for details.
Use_Constraints:

These data are intended for use at approximately 1:1,000,000 scale or smaller. There is no guarantee concerning the accuracy of the data. Any user who modifies the data is obligated to describe the types of modifications they perform. Data have been checked to ensure the accuracy. If any errors are detected, please notify the originating office. The U.S. Geological Survey strongly recommends that careful attention be paid to the metadata file associated with these data. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. User specifically agrees not to misrepresent the data, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey. Please refer to http://www.usgs.gov/privacy.html for the USGS disclaimer.

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   USA

   1-888-ASK-USGS (1-888-275-8747) (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? Downloadable Data
3. What legal disclaimers am I supposed to read?

   This database, identified as USGS Data Release https://doi.org/10.5066/F7WH2N65, has been approved for release and publication by the U.S. Geological Survey. 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 U.S. Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer System at the U.S. Geological Survey (USGS), no warranty, expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS shall not be held liable for improper or incorrect use of the data described and/or contained herein. Although this information product, for the most part, is in the public domain, it also contains copyrighted material as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	File geodatabase (version 10.5)
     Network links:	https://doi.org/10.5066/F7WH2N65

   • Cost to order the data: None. No fees are applicable for obtaining the data set.

Who wrote the metadata?

Dates:

Last modified: 31-Jul-2017

Metadata author:

John Horton

U.S. Geological Survey, Southwest Region

Physical Scientist

Denver Federal Center, PO Box 25046

Denver, CO

303-236-1921 (voice)

303-236-3200 (FAX)

jhorton@usgs.gov

Metadata standard:

FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)