--> --> Abstract: Dynamics of Mud Volcano Systems: Evidences from the Southeastern Caribbean and Some Worldwide Comparisons, by Eric P. Deville; #90082 (2008)

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Dynamics of Mud Volcano Systems: Evidences from the Southeastern Caribbean and Some Worldwide Comparisons

Eric P. Deville
IFP, Rueil-Malmaison, France

The dynamics of mud volcano has been studied in Trinidad and the south of the Barbados prism and compared with other examples in the world. In SE Caribbean, it can be shown that a reaction chain of processes developed from deep reservoirs to the surface. Notably, we have shown that the fluids and the solid fraction have different origins. In Trinidad, the gas phase is mainly deep thermogenic methane. The mobilized sediments within the mud are liquefied argillaceous fragments issued from the main regional seals but also thin sandy material issued from deep horizons. Indeed, in all the cases studied, the mud is rich in thin, angular, and mechanically damaged quartz grains, which are probably cataclastic flows issued from sheared and collapsed deep sandy reservoirs. The clasts and breccias result from hydraulic fracturing processes along the mud volcano conduits. The expulsion of the fluids varies according to cyclic phases. Low frequency cycles could develop when high pore pressure occurs at depth, hydraulic fracturing is responsible for the opening of fracture network favoring successive fluid releases and cyclic pressure decreases. A threshold effect when fluids are oversaturated in dissolved gas generating massive gas discharges can also be invoked. The mud volcano edifices observed at the surface are commonly associated with the development of concentric collapses and calderas. The stacking of mud volcano edifices is observed in the high sedimentation areas. Locally, trends of sub-circular structures corresponding to massive uplifts of well preserved turbidite and hemipelagic sediments are observed. They probably correspond to uplift of shallow stratified levels possibly due to the tectonic inversion of pre-existing mud volcano calderas. Finally, it is worth to note that no evidence for piercing shale diapir has been observed in the areas studied.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery