revised: 05-Feb-2015

NMBGMR Draft Geologic Data Model - v. 1.0.4
JOINED & RELATED TABLES: Geochron-Detail

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.

Table Name: Geochronology

This table is used to provide more information for age dates of geologic materials referenced in various other feature classes. If need be, these dates could be linked to a more comprehensive geochronology data model that contains analytical data and discussion.

Field Name Field Alias Length
(text fields)		 Field Type Field Value Default Allow Nulls? Attributes / Examples Description / Notes
SampleID " 50 String variable undefined TRUE ER-09-123 ID of sample dated
GeoID " 20 String variable [null] TRUE Tb ID of rock unit sampled (related to lithology detail)
IsoAge IsotopicAge   Double variable [null] TRUE 23.245 Isotopic age
AgeError "   Double variable [null] TRUE 0.0123 Isotopic age error
TimeUnits " 20 String variable [null] TRUE Ma, Ga, ka, yr BP, C-14 years Units of time
DateMethod " 50 String variable [null] TRUE Ar-Ar, U-Pb, U-series, Rb-Sr, C-14, cosmogenic, paleontology, etc. Method of dating
Material " 255 String variable [null] TRUE sanadine, K-spar, zircon, muscovite, monazite, Calcite, etc. Material dated
Technique " 255 String variable [null] TRUE single crystal, total fusion, whole rock, U-Pb isochron, U-series, etc. Technique of dating
RockType " 128 String variable CVD TRUE plutonic, volcanic, sedimentary, metamorphic Rock type of sample
RockDesc " 255 String variable [null] TRUE Brief description of the rock Description of sample
Interp Interpretation 255 String variable [null] TRUE cooling age, crystallization age, etc. What the age means with respect to the sample.
NumSamples "   Short Integer variable [null] TRUE number of independent analyses used to compute date Number of samples
ProvnclAge ProvincialAge 255 String variable [null] TRUE Blancan, Osagean, Santonian Provincial age
SourceID " 128 String variable [null]   unknown; unspecified; Smith, 2006b [variable] Feature level metadata (who mapped this); related to bibliographic detail
Report " 128 String variable [null] TRUE link to analytic data (e.g. internal reports) Report ID
ReportDate "   date variable [null] TRUE Date report/reference was released/published Report date
Comments " 255 String variable [null] TRUE   Comments about this particular date.