Integration of the Graphic Correlation Methodology in a Sequence Stratigraphic Study

John E. Neal, Jeffrey A. Stein, James H. Gamber

The composite standard method of biostratigraphy (through graphic correlation) provides a consistent temporal framework for stratigraphic analysis of a basin. The method crossplots biostratigraphic data from an individual section against an ideal composite standard of all fossil markers encountered locally and/or globally. A line of correlation (LOC) can be interpreted from these plots, resulting in a quantification of deposition and stratigraphic lacuna at the location being tested.

Sequence stratigraphy is a stratigraphic interpretation method that genetically relates deposits in a dip profile to relative changes in sea level, based on physical surfaces in the rock record. This approach differs from traditional lithostratigraphy (where stratigraphic units are often time-transgressive) and standard zonal biostratigraphy (which is discipline-specific and correlates ephemeral faunal breaks that may have no relationship to physical bounding surfaces in the rocks). Weaknesses in graphic correlation (underuse and static application) match well with strengths in sequence stratigraphy. Weaknesses in sequence stratigraphy (documentation and consistency) can be equally well matched with the strengths of graphic correlation. Sequence stratigraphic key bounding surfaces cau e predictable patterns in the graphic correlation of biostratigraphic data. Integration of graphic correlation and sequence stratigraphy enhances the utility of both stratigraphic tools and provides a powerful basin analysis technique.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995