HGS General Dinner Meeting

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An extreme sea-level fall is supported by the presence of deep paleocanyons across shelves and slopes, the sudden deposition of massive sandstones hundreds of kilometers from paleoshelf margins, salt and redbeds in the Veracruz Basin, and a deep water unconformity marked by paleokarst near the Yucatan Straits at the mouth of the Gulf of Mexico. The trigger for this event was closure of the 200 km wide deep water strait between the Gulf and the world ocean by the northward advancing Caribbean Plate (Cuban Arc) as it docked against the high-standing Yucatán and Florida-Bahamas blocks. 

Evaporation far exceeded rainfall and runoff into the isolated basin, thereby lowering the Gulf by about 2,000 meters within a few thousand years. The release of hydrocarbon gases from hydrates and disrupted thermogenic reservoirs may have exacerbated the Paleocene-Eocene Thermal Maximum. The barrier was breached after about 1 Ma as Cuba moved east relative to Yucatán. A deep erosional thalweg in the eastern Gulf formed during rapid refill of the basin.

Synoptic understanding of the Gulf of Mexico has been difficult to achieve because of the poor communication among U.S., Cuban and Mexican investigators. Moreover, petroleum companies working in the Gulf are reluctant to release information of a confidential nature. In spite of these constraints, data that has become available since this idea was first published in 2002 continues to point to sea level drawdown as the least improbable explanation for the aforementioned phenomena. In spite of these obstacles, we believe that the idea merits dedicated investigation by a consortium of industry and academic scientists, particularly as additional information is forthcoming from petroleum exploration in the eastern Gulf offshore Mexico, Florida and Cuba.