Structural Relations Between Lesser Antilles, Venezuela, and Trinidad-Tobago: ABSTRACT

Abstract

More than 2,500 nautical mi of seismic-reflection profiling, gravity, magnetic and bathymetric data were collected in 1968 by the ESSA Coast & Geodetic Survey ship Discoverer. End_Page 2045------------------------------ A review of the structural geology of the southeastern Caribbean and the South American continent in conjunction with the ESSA data supports a relatively simplistic explanation for the geologic structure. The Barbados ridge was found to be a strongly fractured anticlinorium, supported by basement rocks, and consisting of two parallel arches with a central syncline. The Lesser Antilles volcanic arc, the Tobago trough, and the Barbados anticlinorium are traceable into the Venezuelan and Trinidadian shelves (South American continent). An analogy between the Caribbean island arc system and previous work done in the Andaman Sea (Indonesian island arc) shows the validity of the concept of continuation of continental mobile belts into island arc systems. The mobile belt and the island arc system are manifestations of orogeny in different crustal types. Evidence is against wrench faulting, with its implication of vast horizontal movements of individual blocks. The island arc structural belts and the mobile belts of the continent are interrelated, gradational, and interlocked. End_of_Article - Last_Page 2046------------