Problems in Application of Modern Tectonic Hypotheses to Cuba and Caribbean Region

Abstract

Within the framework of the Caribbean, structures may be classified according to the type of crust and the character of its Mesozoic-Cenozoic development. Magmatic activity associated with Benioff zones has undergone a continuous clockwise rotational movement from Paleozoic until recent time. Within Cuba, it is proposed that the original crust was of the modified oceanic type. The Benioff zone of Cuba, no longer active today, dipped from north to south beneath the island. The geologic evolution of Cuba can be divided into three stages: (1) an oceanic stage until Tithonian time; (2) an island-arc stage from Tithonian until middle Eocene time; and (3) a platform stage from the late Eocene until the recent. If one applies the new global tectonics to the problem, a model emerges according to which lithospheric plates must form to explain the structure and geologic composition of Cuba and the Caribbean. This model supposes a Pacific origin for the Caribbean plate, the movement of which was considered to be active between Tithonian and middle Eocene times. Several facts support this hypothesis, but others negate it. Finally, the fracture-contraction hypothesis is applied to the geology of Cuba and of the Caribbean. The fracture-contraction hypothesis explanation is based on a rotation of the axis of maximum compressive stress which, in turn, is designed to explain the continuous rotational clockwise movement of the loci of magmatism and the associated tectonic processes. The fracture-contra tion hypothesis explains most logically the observed regularities within the Caribbean realm.