Print this pageCharacteristics of Hydrocarbon Seep-Related Rocks
from the Deep Gulf of Mexico
Dong Feng1, Harry H. Roberts2, Pengfei Di1, and Duofu Chen1
1CAS Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry,
Chinese Academy of Sciences, No. 511, Kehua St., Tianhe District, Guangzhou 510640, China
2Coastal Studies Institute, Department of Oceanography and Coastal Sciences, Louisiana State University,
331 Howe-Russell Geosciences Complex, Baton Rouge, Louisiana 70803
ABSTRACT
The present study investigates the megascopic characteristics of nearly a hundred hydrocarbon seep-related carbonate rock samples, collected during 2006 deep submergence vehicle (DSV) Alvin and 2007 remotely operated underwater vehicles (ROV) Jason dives from 15 locations from the middle and lower continental slope, northern Gulf of Mexico. These rocks are composed mostly of high Mg-calcite and aragonite, but a significant amount of dolomite occurs at some sites. Several types of hydrocarbon seep-related limestones can be distinguished, including nodules, chimneys, slabs, blocks, and irregular shaped aggregations based on their morphologies.
All types of carbonates are closely related to the seep fauna, e.g., rich in fossil shells and burrow activity relics. The
megascopic characteristics and possible formation mechanisms for each type of limestones are presented. Through our study, we hope to access to
more environmental, chemical, and biological information concerning these hydrocarbon seep systems. Overall, our results suggest that the heterogeneities
in macrofacies of these carbonate rocks probably reflect local controls, e.g., hydrocarbon seep rates at the formation sites.
Feng, D., H. H. Roberts, P. Di, and D. Chen, 2009, Characteristics of hydrocarbon seep-related rocks from the deep Gulf of Mexico: Gulf
Coast Association of Geological Societies Transactions, v. 59, p. 271-275.
AAPG Search and Discover Article #90093 © 2009 GCAGS 59th Annual Meeting, Shreveport, Louisiana