ABSTRACT: Global Cyclostratigraphy, Sediment Flux and Continental Margin Stratigraphy

PERLMUTTER, M. A., and M. D. MATTHEWS, Texaco Inc., Houston, TX

Idealized models of stratigraphic response to sea level change commonly assume constant rate and timing of sediment supply to continental margins and ocean basins. However, a Global Cyclostratigraphic evaluation of sediment yield indicates flux to margins may vary by up to an order of magnitude during climate cycles caused by Milankovitch oscillations. Rather than occurring at one particular stage of sea level, maximum transport to margins and basins may occur at any phase of glacioeustasy. Magnitude and timing of sediment flux depend on the climatic succession and topography of the drainage basin. High supply concurrent with highstand sea level will tend to bias preservation of highstand deposits and minimize lowstand deposits. Conversely, high supply at lowstand sea level will tend o bias preservation of lowstand deposits and minimize highstand deposits. Interpretation of the magnitude of short-term glacioeustatic changes may therefore be influenced by the paleogeography (i.e., climatic succession) of the drainage basin. Interpretation of the direction of longer term sea level changes may be influenced by a shift in timing of sediment supply relative to sea level caused by continental drift of the drainage basin through different climatic belts. Timing of sediment flux relative to sea level change can have marked effect on the distribution of potential reservoirs within systems tracts.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)