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Allostratigraphic Unit
A mappable stratiform
body of sedimentary rock that is defined and identified on the basis of its
bounding discontinuties.
Allostratigraphic Units, in order of decreasing rank are allogroup,
alloformation, and allomember. The
fundamental unit is the alloformation (NACSN, 1983).
NACSN, 1983
Limit of
Discontinuity
Units extend only to limits of bounding
discontinuities
As discontinuity ends, New
discontinuity-bounded Unit begins