--> Abstract: Source Rock Potential of Organic Matter in Caicos Salinas and Tidal Flats, Turks and Caicos Islands, by Arthur Saller, Clark Weaver, and Joseph Curiale; #90078 (2008)

Datapages, Inc.Print this page

Source Rock Potential of Organic Matter in Caicos Salinas and Tidal Flats, Turks and Caicos Islands

Arthur Saller1, Clark Weaver2, and Joseph Curiale2
1Chevron, Houston, TX
2Chevron, Sugar Land, TX

Dark organic mats from the Great Salina of West Caicos and a tidal flat in the middle of Little Ambergris Cay were analyzed for source rock potential. Both have excellent characteristics for generating oil. The samples were oven-dried (40°C) prior to analysis. The West Caicos sample was a gelatinous mat associated with a gypsum-filled salina. The salina is flooded during rains, but then evaporation dominates until the salina becomes completely dry. The Great Salina sample had a total organic carbon (TOC) content of 4.05 wt % and a hydrogen index (HI) of 694 mg/g. The sample from the middle of Little Ambergris Cay was a filamentous cyanobacterial mat at the top of a Holocene succession dominated by carbonate sands (grainstone). That sample had a TOC content of 7.32 wt % and HI of 677 mg/g.

Both samples are highly oil-prone with hydrogen index values approaching 700 mg/g. (Note that Rock-Eval analysis was developed, tested and calibrated using rock samples; therefore, its application for recent sediment is speculative.) With burial, both of these samples would become oil-prone source rocks with substantial ability to generate crude oil upon entering the thermal oil window. Preservation of this type of material is dependent on burial in anaerobic environments. Very little of the organic carbon in these samples (about 0.2% of the rock by weight) is soluble in standard organic solvents, indicating that most of the organic matter in the samples would be classified as kerogen.

 

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas