A GEOCHEMICAL ANALYSIS OF THE TUSCALOOSA MARINE SHALE (UPPER CRETACEOUS) CORE RECOVERED FROM EADS POITEVENT ET AL. #1

A core recovered from Eads Poitevent #1 in the Lacombe Bayou Field of St. Tammany Parish, Louisiana, contains a complete section of the Tuscaloosa Marine Shale (TMS). The TMS is an organic-rich shale interbedded with sandstones and siltstones, deposited on the shelf of the Gulf of Mexico during the Upper Cretaceous. Regionally, the TMS extends from central Louisiana to western Mississippi and is estimated to encompass an area of 8,250 square miles and can be found at depths as great as 15,000 feet. Due to the Gulf of Mexico being a mature producing province, the TMS is believed to be a possible unconventional resource play that contains up to 7 billion barrels of oil. During the Late Cretaceous, the Gulf of Mexico experienced periods of anoxia, including the Oceanic Anoxia Event #2. This anoxic event is believed to have occurred at the Cenomanian and Turonian boundary, which could be recorded in the TMS. The TMS will be used as a geochemical proxy for the Gulf of Mexico during the Late Cretaceous by determining the geochemical stratigraphy of the core.

XRD will be used to determine the mineralogic composition of the core. XRF will be used to determine the ratio of trace elements found within the core, giving insight into oxidation conditions during this time. Trends in both major and trace elements will be determined to correlate geochemical conditions at the time of deposition. RockEval pyrolysis will be used to determine kerogen type and amount of total organic carbon (TOC) found within the core. Preliminary data from RockEval pyrolysis determined the S1 peak to be poor, S2 peak to range from poor to fair, and TOC to range from fair to good. This data set will be used as a geochemical proxy for the Gulf of Mexico during the Late Cretaceous and yield insight into the precise location of the Oceanic Anoxic Event # 2 within the core.