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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 57 (1973)

Issue: 2. (February)

First Page: 430

Last Page: 430

Title: Criteria for Biostratigraphic Correlation: ABSTRACT

Author(s): William B. N. Berry

Article Type: Meeting abstract

Abstract:

Biostratigraphic correlations are established using stratigraphic sequences in which a succession of congregations of taxa have been recognized as standards of reference. Recognition of a succession of congregations in any part of the overall geologic column results from (1) detailed measurement of many stratigraphic sections through a part of the overall stratigraphic column under close study with fossil collections obtained from the measured sections such that the precise stratigraphic position of each collection is known; (2) identification of taxa in each collection (commonly one organismal group such as the foraminifers is selected for close taxonomic analysis); (3) plotting of the stratigraphic ranges of each of the taxa in every measured section; (4) recognition of superpositionally unique associations of taxa in each section by analysis of the overlapping stratigraphic ranges, section by section; and (5) recognition of congregations in the area in which the stratigraphic sections were measured, based upon comparisons among the superpositionally arranged unique associations in each individual section. A composite succession of unique associations or congregations recognized in an area provides a standard of reference with which collections of fossils from rocks in the same and adjacent areas may be compared and correlations established on the basis of the closest match between the new collection and the congregations in the reference suite.

New data in the form of new fossil collections from additional stratigraphic sections may reveal range extensions for certain taxa because those taxa may be found associated with congregations other than those in which they were initially found.

Divisions or lumping of congregations may be indicated by new data. Analysis of taxa may include those from a wide range of environments in the steps toward erecting a reference suite of congregations. Alternatively, separate reference suites may be established for each different biofacies within coeval rocks in the area under study. Therefore, criteria for correlation must include analysis of the fossils found to determine their facies relations as well as their stratigraphic superpositional relations. These determinations will aid in erecting the reference successions of congregations, as well as in making comparisons with the reference suites.

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Copyright 1997 American Association of Petroleum Geologists