revised: 05-Feb-2015

NMBGMR Draft Geologic Data Model - v. 1.0.4
LINES: Contacts - Geomorphic Surfaces

In the interests of standardization and interoperability, we are migrating our geologic maps into the USGS NCGMP09 data model. However, our well data model is still actively being used. Documentation for the NMBGMR geology data model is being provided for users with legacy data in this model. We also hope that it will provoke discussion in the ongoing effort to improve NCGMP09 and other models.


This feature class represents contacts bounding geomorphic surfaces (not deposits). Geomorphic surface polygons (Surface_poly) are built from these contacts. Particularly good and/or important exposures of contact relations could be recorded as point data in Feature_point and assigned a special symbol along the contact.

Field Name Field Alias Length
(text fields)
Field Type Field Value Default Allow Nulls? Attributes / Examples Description / Notes
FGDC_code " 16 String variable [null] TRUE 30.3.12 FGDC geologic symbol reference number.
LineClass LineClass 50 String CVD [null] TRUE see: SurfaceMargin Basic class of contact.
IDmethod " 50 String CVD [null] TRUE see: IDmethod The basis for identification of this feature.
Confidence " 16 String CVD [null] TRUE unspecified, certain, probable, uncertain

Confidence regarding the existence/identification of this feature.

Exposure " 16 String CVD [null] TRUE unspecified, exposed, obscured, concealed Exposure of this feature at the surface.
SrfCtType SurfaceContactType 50 String CVD [null] TRUE [upper]-bounding, [lower]-bounding Type of contact bounding the geomorphic surface.
CtNature ContactNature 50 String CVD [null] TRUE see: ContactNature Nature of contact..
Name " 50 String variable [null] TRUE Llano de ABQ Feature name (will generally be NULL)
DsplyScale DisplayScale   Long Integer CVD 24000 TRUE see: DisplayScale Denominator of display scale: display feature at scales larger than number specified (=< denominator). Zero indicates data that should never be displayed.
SourceID " 128 String variable [null] TRUE "Smith, 1999a" Feature level metadata (who mapped this)
Comments " 255 String variable [null] TRUE Free text e.g. "identified from detailed stereo photos" Comments about this particular feature.