Wrench Tectonics in the Geology of Cuba

R. Socorro, S. Lopez

Over 800 kilometers long in the northern region of Cuba, outcropping rocks from the Lower Jurassic to the Quaternary, show the Cuban overthrust belt lying on the Cuban southern basins, where sedimentary filling began to form since the Upper Cretaceous-Tertiary.

The structural displacement of the northern belt towards the northeast is due to a system of wrench faults, with a main strike from southwest-northeast, that makes up the current geological configuration.

By studying the characteristic of numerous seismic sections next to the outcrop, it is possible to differentiate several structures. The origins of which are compression, wrench faulting, and extension. These features may be related to one another.

The wrench system played an important role in the formation of the current Cuban structures. In the overthrust belt to the north, some folds are formed on "en echelon", and the southern basins, are genetically classified as "pull-apart".

It is debated whether the genesis of the Cuban thrusting structure belong to a Cuban compressive laramic system or to the component of compression of wrench system all over the Caribbean region. This system started with the displacement of the Caribbean plate towards the northeast in the Middle Cretaceous, and this movement continues towards the East.

Finally, with the chronological analysis of the different structures, it is possible to propose a logical structural evolution of the island.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995