Testing the controls on the seismic sequence stratigraphy of the Eocene-Oligocene boundary in Southern Iran with a Wheeler diagram derived from outcrops, seismic and well logs data

摘要

In this study of Southern Iran the timing of the boundary between the Eocene to Oligo-Miocene sections was determined along with a better understanding of the accumulation of the Paleocene to Eocene sediments. This was established by generating Wheeler diagrams from local seismic, well log data and surface data. This boundary was found to be mainly erosional and the time gap between Eocene to Oligo-Miocene displayed by the Wheeler diagram suggests a "degradational vacuity" formed. Relative sea level changes were found to be responsible for the seaward progradational character of the Jahrum Formation sediments. Red sediments and an intraformational conglomerate overlie this erosional boundary between the Paleocene to the Eocene Jahrum Formation and the Oligo-Miocene Asmari Formation. Long-term lower frequency trends in both regional tectonic and global sea-level curves determined from the Paleocene-Eocene sediments of south Iran, when compared to the coastal plain sediments of US New Jersey and the global coastal onlap chart, suggest that contemporaneous eustastic signals in lower Eocene time produced matching sedimentary patterns. The results of the study recorded in this paper are intended to be used as the foundation of the study of petroleum related facies and petroleum system components (source, reservoir and seal rocks) in the Tertiary portion of sedimentary section.