11 Structural Geology and Tectonics (Posters)

Sunday, 22 March 2026
8:00 AM - 12:00 PM
CCC, Ballroom C

The Idenification of Newly Discovered Seven Mesozoic Salt Diapirs Using Gravity Geophysical Data Surveys Bahamas

Paper number: 11-4
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

Rifting along the separation zone between North America and Africa occurred during the Early to Middle Jurassic in the area that is now the Bahamas producing extensional faulting, margin basins and grabens . The Great Isaac #1 well, on the northern edge of the Great Bahama Bank, bottomed (5 km) in synrift volcanoclastics, red beds, and evaporites. Seismic records show a breakup unconformity with continued rifting. Marine water flowed into the region during the Early to Middle Jurassic and extensive shallow water carbonates and evaporites were deposited over the Bahamas area (Epstein and Clark, 2009).

The purpose of this presentation is to inroduce  seven Jurassic-Cretaceous age salt diapers, identified in gravity mapping by Alan Spector.Intialy baslnal  syn-rift salt was predicted utilizing Epstein and Clark ( 2209) rift zone arid sedimenary deposiional models based upon straigraphic evaluations from five wells drilled. The postulated salt is correlates with those oil/gas field salt diapirs found offshore NW West African conjugate margin, and in the expansive Mesozoic age salt diapers (Louann salt) in the onshore and offshore circum- Gulf of Mexico including the Campeche Basin, Mexico and in offshore Eastern Canada.

Identification using gravity lows is well established in the northwestern Gulf of Mexico salt ridge.

We have previously published (Spector, Epstein and Schieck, 2016) one of the seven mapped Bahamas salt diapers 20 miles to the northwest of the Long Island well, appears in seismic and gravity (-30mgal anomaly) data analogue to the East Texas Fairway oil field (440mmbo) with Lower Cretaceous carbonate lateral and vertical heterogeneous reservoirs over salt features resulting from a transgressive depositional event. The salt is overlain by porous carbonate reef-derived grainstones, shallow subtidal packstones/wackestones.

The Jurassic to Lower Cretaceous lagoonal basin covering the Bahamas created ideal conditions anoxic and hypersaline for the preservation of organic matter (TOC 1.5 % to 5 % by wt., HI 400 to 500 mg/gTOC). Evaporites occur in select wells of significant thickness (3km.) intercalated with dolomites. The correlative are type 2 algal kerogen carbonates are the, Smackover and Sunniland Formations.

Currently no wells have been drilled into salt. The 7 Bahamas diapirs, inconjucion with modeled petroleum systems from 6  exploratory wells( Epstein et.al.,2025, 2024, 2022, 2021, 2016, 2014, 2010, 2009)  suggest significant unexplored hydrocarbon potential. 

 

  

 

 

  

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411230

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