Late Quaternary shelf-margin deltas, northwest Gulf of Mexico

Journal Article · Sun Dec 01 04:00:00 EST 1985 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:5857793

Suter, J R; Berryhill, Jr, H L

Interpretations of 35,000 km (21,900 mi) of single-channel, high-resolution, seismic profiles traversing the continental shelf and upper continental slope of the northwest Gulf of Mexico indicate the existence of five late Wisconsinan shelf margin deltas, including the Rio Grande and Mississippi deltas. The deltas were recognized by geomorphic pattern, high-angle clinoform seismic reflections, and associated with buried river systems. Isopach patterns show that the deltas range in size up to 5000 km/sup 2/ (1900 mi/sup 2/) and reach thicknesses of over 180 m (590 ft). The deposits are elongate parallel with depositional strike, indicating subsidence of the shelf margin as a whole. Internal reflection patterns show the deltas to be fluvially dominated. Multilobate structure resulted from both short-term eustatic sea level fluctuations and delta switching. The late Quaternary shelf-margin deltas provide models for analogous deposits in the ancient record. They are primary indicators of the position of ancient shelf margins, and are important for predicting sand occurrence in that environment as well as farther downslope. As exploration moves to the shelf edge and beyond, instability hazards posed by late Wisconsin deltas, as well as older deposits, must be understood and dealt with. 20 figures.

• Research Organization: Louisiana State Univ., Baton Rouge
• OSTI ID: 5857793
• Journal Information: Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 69:12; ISSN AAPGB
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ATLANTIC OCEAN
CARIBBEAN SEA
CENOZOIC ERA
COASTAL REGIONS
GEOLOGIC AGES
GEOLOGY
GEOPHYSICAL SURVEYS
GULF OF MEXICO
QUATERNARY PERIOD
RIVER DELTAS
SEAS
SEISMIC SURVEYS
SURFACE WATERS
SURVEYS