This report presents the results of the USGS Mineral Resources Program activity to compile a national-scale geologic map database at a nominal scale of 1:500,000, to support national and regional level projects, including mineral resource and geoenvironmental assessments. The only comprehensive sources for input into 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 as regional blocks of 3 degree quadrangles 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 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 CONUS documentation, standards for the conterminous U.S. are somewhat different than those for Alaska and Hawaii.
Purpose:
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 CONUS documentation of this report. 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 derived from the USGS Digial Line Graph 1:100,000 quadrangle boundaries (Johnson and Leveritch, 1998) 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.
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).
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2005
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: none planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -83.675682
East_Bounding_Coordinate: -75.097580
North_Bounding_Coordinate: 39.465752
South_Bounding_Coordinate: 36.535133
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: geology
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: USA
Place_Keyword: Virginia
Theme:
Theme_Keyword_Thesaurus: National Geologic Map Database Catalog themes, augmented
Theme_Keyword: 3100 - Vector
Theme_Keyword: 3110 - ESRI
Theme_Keyword: 3112 - export
Theme_Keyword: 1100 - Geology
Theme_Keyword: 1101 - General
Place:
Place_Keyword_Thesaurus: Augmented FIPS 10-4 and FIPS 6-4, version 1.0
Place_Keyword: US51 = Virginia
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.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Suzanne W. Nicholson
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing and physical address
Address: 12201 Sunrise Valley Dr. MS954
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703-648-6344
Contact_Electronic_Mail_Address:swnich@usgs.gov
Data_Set_Credit:
State Geologic Map Compilation (SGMC) activity of the National Surveys and Analysis
projects of the US Geological Survey Mineral Resources Program.
Native_Data_Set_Environment:
ARC/INFO version 8.3 and 9.0
ArcView 3.2
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
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 Classification version 6.1 (Johnson and others); available at the following website: <http://www.nadm-geo.org/dmdt/index.html>
Logical_Consistency_Report:
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.
Completeness_Report:
Bodies of water are classified as water, and the geologic units underlying them are not included in this coverage.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Accuracy of Virginia state boundary and those arcs intersecting it: The accuracy of the state boundary arcs is based on the 1:100,000 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).
Those internal arcs intersecting the state boundary were extended or shortened as needed to complete polygons, possibly creating a small amount of error.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Virginia Department of Mines, Mineral and Energy
Publication_Date: unpublished
Title: Geologic Map of Virginia
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Charlottesville, VA
Publisher: Virginia Department of Mines, Mineral and Energy
Source of lithologic codes and specific rock names found in ROCKTYPE1 and ROCKTYPE2.
Process_Step:
Process_Description:
The purpose of this standardization is to allow all 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 State Geologic Map Compilation (SGMC) effort, with Stoeser coordinating work on the mainland states and Wilson coordinating work for Alaska and Hawaii.
Process_Date: 2003 - 2005
Process_Step:
Process_Description:
C.L. Dicken received the digital geology file from Karen Hostettler of the Virginia Department of Mines, Mineral and Energy on July 12, 2005 by ftp.
The coverage was re-projected 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: 0.00000
false northing: 0.00000
All attributes were deleted except geology.
(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 geology where then calculated into a new field called orig_label.
Process_Date: 2005
Process_Step:
Process_Description:
The relevant state outline (arcs) was removed from the coverage and replaced with the arcs from the 1:100,000 Scale State Boundaries of the Conterminous United States.
This allows for a seamless fit of each state to a standard state boundary base.
Process_Date: 2005
Process_Step:
Process_Description:
The following attributes were exported from Filemaker as a .dbf:
orig_label, map_symbol2, unit_link, reference_id, unit_age, rocktype1, and rocktype2.
orig_label reflects the original map symbol used on the source map
map_symbol2 reflects map-symbol1 with the addition of a province number (renamed sgmc_label in PAT)
unit_link is an auto generated field based on map-symbol2 and the state abbreviation (e.g. IN001) that produces a unique identifier for each map unit
reference_id was populated with an alphanumeric code (e.g. US001) that designates the source used for the linework and other references used to describe the age or lithologies of the unit. (renamed source in PAT).
unit_age was populated with general age assignment
rocktype1 records dominant lithology (must be >50% of unit), using standardized data dictionary
rocktype2 records second most dominant lithology, using standardized data dictionary
The attributes were then converted using the following structure:
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
Process_Date: 2005
Process_Step:
Process_Description:
Once the .dbf was in the correct format with standardized column widths and data structure, it was converted into a lookup table (.lut) in Arc/Info. Then a joinitem was performed to join the look-up table to the polygon attribute table. orig_label was used as the merge item.
Process_Date: 2005
Process_Step:
Process_Description:
Next, in preparing the uniform .aat file, 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
Process_Date: 2005
Process_Step:
Process_Description:
Arc-code was populated using the paper map source to tag the lines using the AAT line type data dictionary (see CONUS documentation in this report).
Arc-para1 was populated when additional information was available such as identifying the upthrown side of a fault or direction of thrusting on a fault. (see CONUS documentation)
Arc-para2 is a scratch field that is used mostly in Alaska.
Source was populated with an alphanumeric code (e.g. US001) that designates the source used for the linework.
Process_Date: 2005
Process_Step:
Process_Description:
Once the .aat and the .pat were populated with the correct attributes, the coverage was exported as an .e00 file (VAgeol_lcc.e00).
Then it was unprojected into geographic coordinates and exported again (VAgeol_dd.e00).
Process_Date: 2005
Process_Step:
Process_Description:
Separate faults were received from DMME and the fault coverage. The arcs were attributed with arc-code = 30. The file was projected into the Lambert projection and saved as VAfaults_lcc. It was then exported as VAfaults_lcc.e00.
Process_Date: 2005
Process_Step:
Process_Description:
Finally, the geology lines and geology polygons were converted into shapefiles; in both geographic coordinates and in Lambert Conformal Conic projection.
composite map label = ST + sgmc_label
This creates a unique identifier for every unit in the CONUS (continental United States) covers.
type: character
width: 18
output width: 18
Attribute_Definition_Source: Doug Stoeser
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: VAadg;0
Enumerated_Domain_Value_Definition: Altered Diorite and Gabbro
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: VAaf;0
Enumerated_Domain_Value_Definition: Artificial Fill
An alphanumeric code (e.g. US001) that designates the source material used.
type: character
width: 6
output width: 8
Attribute_Definition_Source: Doug Stoeser
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: VA003
Enumerated_Domain_Value_Definition:
Digital Representation of the 1993 Geologic Map of Virginia”, 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: US001
Enumerated_Domain_Value_Definition:
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)
Attribute:
Attribute_Label: unit_age
Attribute_Definition:
The geologic age from the source map used.
type: character
width: 60
output width: 60
Enumerated_Domain_Value_Definition: state boundary
Attribute:
Attribute_Label: arc-para1
Attribute_Definition:
Used for "decorated" lines where additional information is needed.
type: integer
width: 3
output width: 3
Attribute_Definition_Source: AAT data dictionary
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 0
Enumerated_Domain_Value_Definition: no additional information
Attribute:
Attribute_Label: arc-para2
Attribute_Definition:
"Scratch" field used mostly in Alaska.
type: integer
width: 3
output width: 3
Attribute_Definition_Source: AAT data dictionary
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 0
Enumerated_Domain_Value_Definition: no additional information
Attribute:
Attribute_Label: source
Attribute_Definition:
An alphanumeric code (e.g. US001) that designates the source material used.
type: character
width: 6
output width: 8
Attribute_Definition_Source: Doug Stoeser
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: VA003
Enumerated_Domain_Value_Definition:
Digital Representation of the 1993 Geologic Map of Virginia”, 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: US001
Enumerated_Domain_Value_Definition:
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)
Overview_Description:
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
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
U.S. Geological Survey Information Services
Reston-ESIC
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ARC/INFO export
Format_Version_Number: 9.0
Format_Information_Content: Geologic units and structural features