Abstract: Hurricane Impact on Continental-Shelf Stratigraphy, Gulf of Mexico
Barton Birdsall, Robert G. Steward
At the time Hurricane Eloise (September 1975) crossed the northeastern Gulf of Mexico, box coring and water-column-particulate measurements were being collected in the path of the storm. The shelf survey began 1 year prior to the storm and continued until 3 months after. Analysis of sediment size and composition, radiographs, and epoxy-relief casts revealed homogenous, structureless sediments comprising three distinct sedimentary facies. Cyclic seasonal changes were apparent over the 2-year period, showing removal of the fines in winter and redeposition during the summer. Eloise left no detectable changes in the stratigraphic record other than minor resuspension of the fines which was indicated by a water-turbidity layer and a small change in the percent fines from cores collected alo g the storm track 48 hours after landfall. Density and speciation of the benthic fauna also failed to change significantly following the storm. The estimated volume from suspended-material calculations shows that less than 2 cm of surficial sediments would supply enough fine-grained material to maintain the overlying nepheloid layer. However, seasonal-sedimentation patterns suggest that the frequency and organization of winter storms had a greater impact on the stratigraphic record on the West Florida shelf than did Hurricane Eloise.
AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC