Hint of a "Lost World" beneath the sea, a survivor of long-gone geologic ages
, has been hauled up in a trawler's net off the east coast of South Africa: a fish of a kind supposed to have disappeared utterly from the earth 50 million years ago.
As an early (pre-NCGMP) and therefore deprecated alternative, ESRI incorporated an additional relation in which geologic ages are modeled via a relation consisting of attributes that are hierarchically organized.
3, stratigraphic names and geologic ages are simple attributes on the feature class level for a given rock unit.
Geologic ages are related to eras via relationship classes so that erroneous data entries are avoided, however, assignments of, e.