Print this pageAbstract: Anomalously Radioactive Barite Chimneys and Crusts from Hydrocarbon Seeps, Gulf of Mexico Slope: Initial Report
Baoshun Fu, Paul Aharon, D. L. Van Gent, L. M. Scott
Barite chimneys and crusts recovered by submersible dives from hydrocarbon seeps at water depths of 510-670 m in the Gulf of Mexico offshore Louisiana are enriched in 226Ra and 228Ra at levels of 780 pCi/g and 470 pCi/g, respectively. These values are comparable to those found in barite scale associated with hydrocarbon production in the Gulf Coast. The concentrations of 226Ra in the pore fluids from sites where active barite deposition occurs range from 830 to 52000 dpm/100L and are consistent with the range of 226Ra values measured in produced waters from offshore platforms. These radium concentrations are highly anomalous as they exceed by a factor of 80 to 5200 the values reported from the Gulf of Mexico seawater (10 dpm/100 ). We speculate that the high radium levels in the fluids advecting to the seafloor originate from leaching of deep-seated, kerogen-rich, source rocks by highly saline formation fluids.
The environmental impact of the natural discharge of the highly radioactive fluids on the Gulf of Mexico seafloor and habitats needs to be investigated.
AAPG Search and Discovery Article #90950©1996 AAPG GCAGS 46th Annual Meeting, San Antonio, Texas