| Description |
A total of 96 core samples from seven DSDP-IODP sites were analyzed for new paleoenvironmental (microfossil-based) and organic geochemistry data (TOC and pyrolysis) to compare and contrast potential source rocks of Cenomanian-Turonian age belonging to the Central Atlantic conjugate margins (East Coast U.S. and NW Africa). Based on the premise of a shared tectonic history around a supposedly ocean-wide anoxic event, OAE2, it was expected that the Cenomanian-Turonian paleoenvironmental conditions and source rock origin and character would be comparable. The results from this study show otherwise, suggesting that a combination of local and regional paleoenvironmental factors impacted not only the organic matter type, but also the quality and/or quantity of organic matter that could potentially generate hydrocarbons. Although best source rock potential, as based on high TOC values and more oil-prone kerogen types, is observed in the OAE2 interval throughout both margins, the southern Central Atlantic sites, which recorded more frequent anoxic events, appear to hold more promise than the northern sites. The southern sites on the NW African margin have the best source rock potential, based on fewer intervals with benthic foraminifera (indicating anoxic conditions), low terrigenous input (thus not diluting marine organic matter), high TOC values, and more oil prone organic matter. Overall, there is more heterogeneity than homogeneity in the potential source rock character during this time along the Central Atlantic conjugate margins. |
