The Biostratigraphic Package Approach to Regional Sequence Stratigraphy and Exploration

LANE, H. R., Amoco Production Co., Houston, TX, and M. W. FRYE, Resource Consulting Group, Morrison, CO

The "Biostratigraphic Package Approach" to regional sequence stratigraphic interpretation is an exploration-oriented set of procedures that promotes and facilitates the multidisciplinary integration of paleontological, geological, and geophysical data and leads to a functional correlation framework. Basic to the approach is the recognition of a new biostratigraphic unit termed a "Biothem," which is here defined as a modified wedge- or lens-shaped body of strata that is: (1) bounded in its updip or near-shore extent by paleontologically recognizable unconformities, (2) conformable with underlying and overlying biothems in its maximum, ideal shelfal development, (3) where applicable, conformable or bounded by surfaces of nondeposition and/or submarine erosion in its downdip basinal or " tarved" equivalent, and (4) characterized by a logical sequence of depositionally related facies.

Biothems are practical units whose definitions and degree of refinement are solely dependent on the quality and availability of biostratigraphic control. Thus, biothems may transcend stratigraphic rank but are conceptually the same as any of W. H. C. Ramsbottom's three unconformity-bounded units (Synthem, Mesothem, and Cyclothem). Ideal individual biothems, expecially those of Mesothem or Cyclothem rank, are interpreted to be depositionally related and most likely equivalent to one transgressive-regressive depositional sequence. Biothems, as derived from the Biostratigraphic Package Approach, are most useful for establishing a time-stratigraphic framework in which to perform areal resource evaluations, especially in cratonic sequences, where seismic stratigraphic methods may not resol e carbonate on carbonate unconformities or sequence boundaries.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)