Miocene Current-Modified Submarine Fans

Abstract

Abstract

In the offshore areas of Mexico northeast of Veracruz, has been recognized what it seems to be Miocene-age contourites, deposits from strong ocean bottom currents that modified submarine fans and transported sediment to the north. Those contourites were identified on older seismic data. I worked with data from the University of Texas, publications and donated seismic. Now, there is access to newly reprocessed seismic which images these contourites much clearer. This project map out and investigate the origin and extent of fans and contourites that extends over a large area of the Gulf of Mexico. These are located close to the seafloor over much of the area, though deeper and older analogs may exist elsewhere in Mexico.

The Miocene is an epoch that marks a transition into Basin-and-Range extension. In the Early Miocene submarine fans systems were formed by the orogenic activity in Mexico, it means that these submarine fans were the result of increased uplift and erosion of the Mexican landmass that was deposited in deep water. The submarine fan development persisted in the Middle Miocene due a continued uplift and erosion of the Mexican landmass. Also in this epoch started develop a small contourite drift complex in deepwater in the north part of the fan. In the Late Miocene the contourite drift reached its maximum extent in the Mexican deepwater area, anchored on its southern end by a submarine mound. This mounded submarine fan is located in the offshore northeast Veracruz and is the result of increased uplift and erosion of the Trans-Mexican volcanic belt that deposited sediments into Mexican deepwater. In the Miocene-Pliocene the large contourite drift continue.

With the seismic and core information has been identified hummocky, oblique and shingled to parallel seismic clinoform reflections. Those shingled seismic reflections in offshore east Mexico has been interpreted as contourite drifts. This current modified deepwater deposits in the seismic lines we can identify that shingled clinoforms dip to the north and northeast. This contourite formation has a thickness between 130 to 200 meters. This research is important to understand more about the Gulf of Mexico and also for the Miocene timeframe that is a key phase in the earth's history.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016