The North Carolina Department of Environment, Health, and Natural Resources, Division of Land Resources, NC Geological Survey, in cooperation with the North Carolina Center for Geographic Information and Analysis, developed the GIS data set version of the Geology of North Carolina. The data represents the digital equivalent of the official State Geology map (1:500,000-scale), but was digitized from (1:250,000-scale) base maps. This file contains the line attributes which identify faults in North Carolina. The geologic formation id is the only attribute present. There are two additional files which accompany this layer, formations and dikes. These should be used together with the faults layer. All three files come together. (Refer to the cross references section for more detail on the formations and dikes).
This data was created to assist governmental agencies and others in making resource management decisions through use of a Geographic Information System (GIS).
This data includes three coverages: geol250, which contains geologic formations; geol250d, which contains dikes; and geol250f, which contains faults. To purchase a hardcopy of this data layer (the official 1985 NC State Geologic Map, shown at a 1:500,000 scale), contact: NC Geologic Survey PO Box 27687 Raleigh, NC 27611 (919) 733-2423 As of December, 1995, map cost is approximately $10.00. Call to confirm availability and price. This coverage corresponds to the DOT county boundary file. Other county boundary files may not be compatible with this layer. >system filename: geol250f file size = 0.2 mb > >Revisions and updates to this layer include: >3.) filename: geol250f1298 The December 1998 update to this layer >consisted of projecting the data from NAD27 datum, State Plane >projection, units of measure feet TO: NAD83 DATUM, State Plane >PROJECTION, UNITS OF MEASURE METERS. This was done to comply >with the NC Geographic Information Coordinating Council's >"Statement of Direction for North Carolina Corporate Geographic >Database Horizontal Reference, Datum and Unit of Measure". >This reprojecting was done in various ways depending on the >data type and content. Vector data was projected using the >'project' command in ESRI's Arc software and topology was >cleaned and built based on coverage needs. Raster data was >projected using ESRI's Grid module and various steps as applicable. >2.)geol250f93 - This represents the 1993 version which contains >the following correction. In the spring of 1993, a geologic >formation (ZYba, Amphibolite) in Macon County was added in order >to correct the digital file of the formation layer. This formation >had been omitted in the original digitization. The file containing >the omitted information has been deleted. The associated files names >are: geol250d for dikes and geol250 for formations. >1.) filename: geol250f86 The 1986 version was the first release. >(previously named nc250.geoflt).
Data creation and edit dates
Acknowledgement of products derived form this data set should cite the following: The source of the Geologic (1:250,000) Faults data is the North Carolina Corporate Geographic Database. Earlier versions of this data set may exist. The user must be sure to use the appropriate data set for the time period of interest. While efforts have been made to ensure that these data are accurate and reliable within the state of the art, CGIA cannot assume liability for any damages or misrepresentation caused by any inaccuracies in the data or as a result of changes to the data caused by system transfers.
512 N. Salisbury Street
Preferred contact is by mail or telephone.
>Division of Land Resources Director, Charles H. Gardner >NC Geological Survey Chief, Jeff Reid >NC Dept. of Environment, Health, and Natural Resources >512 N. Salisbury Street >Raleigh, NC 27604-1148 > >NCCGIA Director, Karen Siderelis >Database Administration, Zsolt Nagy >Database Management, Ken Shaffer >North Carolina Center for Geographic Information and Analysis >Governor's Office >Office of State Planning >301 North Wilmington Street, Suite 700 >Raleigh, NC 27601-2825
NCCGIA digitized the geology features and faults from mylar stable bases identifying boundary and name attributes of geologic features. A review by check plot overlay was used to determine label discrepancies and found discrepancies were corrected.
Using ESRI's ARC/INFO GIS software, the dataset was built for arc topology using the "build" command. The data set was then cleaned with a fuzzy tolerance of 1 foot. Topology has not been edited since the last build or clean.
These data represent faults found on the official geologic map of North Carolina. The information consists of three coverages, which depict the state's geologic formations, its faults, and its dikes. Only geology formation names are attributed.
No official accuracy assessment has be performed on this data set. The digital files were checked to within a linewidth of the original base maps. The base maps were delineated with geologic extents identified by the U.S. Geological Survey and the NC Geologic Survey.
Data depicting the official geology of North Carolina, on mylar stable bases.
Digitization of faults and formation ID attribution.
Delineation of the official NC State Geologic formations.
512 N. Salisbury Street
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Digital conversion of the geologic formation delineations through the use of Calcomp digitizing tables into ESRI's ARC/INFO software.
301 North Wilmington Street, Suite 700
Phone and electronic mail preferred
Dataset copied.
Feature geometry.
ESRI
Internal feature number.
ESRI
Feature geometry.
ESRI
An arc coverage depicting the faultS located on the official geologic map of North Carolina (1985) as published by the NC Geological Survey and the US Geologic Survey. The information consists of three coverages: geologic formations, dikes, and faults. The arc attribute table (AAT) includes computer generated identifiers and the length of the arc. >GEOL250F.AAT Arc Attribute Table >COLUMN ITEM NAME WIDTH OUTPUT TYPE DEC DESCRIPTION >1 FNODE# 4 5 B - From-node id of linear feature >5 TNODE# 4 5 B - To-node id of linear feature >9 LPOLY# 4 5 B - Left-side polygon id of linear >feature >13 RPOLY# 4 5 B - Right-side polygon id of linear >feature >17 LENGTH 4 12 F 3 Length of linear feature in meters >21 GEOL250F# 4 5 B - Internal id number >25 GEOL250F-ID 4 5 B - Internal id number
Refer to: "Geologic Map of North Carolina, 1985" for a hardcopy version, and detailed descriptions of the Major Litho-Tectonic Features, Geologic Time Scale, and Paleozoic Metamorphic Facies.
301 North Wilmington Street, Suite 700
Phone and electronic mail preferred For current price information use a web browser: COST INFORMATION - http://www.cgia.state.nc.us/cost.html
NCCGIA is charged with the development and maintenance of the State's corporate geographic database and, in cooperation with other mapping organizations, is committed to offering its users accurate, useful, and current information about the state. Although every effort has been made to ensure the accuracy of information, errors and conditions originating from physical sources used to develop the corporate database may be reflected in the data supplied. The client must be aware of data conditions and bear responsibility for the appropriate use of the information with respect to possible errors, original map scale, collection methodology, currency of data, and other conditions specific to certain data. NCCGIA does not support secondary distribution of this data. The use of trade names or commercial products does not constitute their endorsement by the NCCGIA or North Carolina State Government.
Data creation and large data analysis jobs contact Database Administration P:(919)733-2090. All data is available through standard ordering procedures on a cost recovery basis.
301 North Wilmington Street, Suite 700
Phone and electronic mail preferred