Chronostratigraphy and regional structure in Ship Shoal, South Marsh Island, and High Island Areas, offshore Gulf of Mexico

Abstract

Chronostratigraphy and regional structure in Ship Shoal, South Marsh Island, and High Island Areas, offshore Gulf of Mexico Abu N. Chowdhury, Schlumberger/Geco-Prakla south and upward into the younger sedimentary sections creating the Ewing bank thrust system to the south (Figure 2). Summary The thrusting separates the southern Green Canyon 18 salt from the Mahogany salt. The GC 18 salt is in the evacuation This integrated study establishes the chronostratigraphic framework and reveals major structural elements in the Ship Shoal and South Marsh Island South Additions, offshore Louisiana, and in the High Island South Addition, offshore Texas. Gulf of Mexico. Data utilized in this study included a large 3D volume of seismic data, extracted regional arbitrary seismic lines, biostratigraphy. well logs. sequence stratigraphy, and check-shot velocities. Three key extracted N-S lines approximately 40. 60. and 30 miles long are used (Figure 1) to depict the results in Ship Shoal, South Marsh Island and High Island areas South Addition, respectively. stage because of loading by Pliocene and recent sediments which have depressed the salt, creating turtle structures in the overlying sediments. Several young fault systems created due to complex salt-sediment interplay sole out at the salt face. like salt intrusion and rafting of sediments created repeat sections in the Ship Shoal 349 Mahogany area in the lower Pliocene as indicated by the biostratigraphic data