Metamorphic rocks of the Araya Peninsula,Eastern Venezuela

Two grades of metamorphism, both subfacies of the greenschist facies of regional metamorphism, were mapped on the Araya Peninsula: 1. the quartzalbite-epidote-almandine subfacies, consisting mainly of a sequence of garnet and kyanite quartz-mica schists, interlayered with quartzites; and 2. the quartzalbite-muscovite-chlorite subfacies, which consists of chloritic phyllites, quartzmica schists and phyllites, metaconglomerates, calcareous quartz-mica schists, limestones and marbles, and calcareous epidote schists of volcanic origin. The two subfacies are separated by faults. The probable age of these rocks ranges from Triassic(?)-Jurassic to Lower and Middle Cretaceous. Serpentinites intrude rocks of the lower metamorphic grade, and are interpreted as tectonically emplaced. The foliation of these rocks is highly folded by mesoscopic folds, whose axes trend east-northeast and which are overturned to the south-southeast. Lineations parallel to the fold axes and thrusting to the south-southeast are common. These structures reflect a macroscopic structure of antiforms and synforms, all affected by a dominant north-northwest to south-southeast tectonic transport. A system of high-angle or vertical longitudinal faults crosses the peninsula from west-southwest to east-northeast. Evidence of recent strike-slip movement was found, although vertical movement has also been important along these faults. Two tectonic styles exist in the metamorphic rocks. The older one is characterized by compression and thrusting in a south-southeast direction. The younger one is represented by longitudinal faults oriented in an east-northeast direction, with vertical and strike-slip movement. They probably reflect the eastward movement of the Caribbean region with respect to South America.