Metallogenic zoning in northwestern venezuela

摘要

Detailed studies carried out by the GeologicalSurvey of Venezuela (Direccion de Geologia) in northwesternVenezuela, between the towns of Carora and Aroa, have revealedimportant metallogenic zone in Lower Cretaceous to Tertiary rocks.The area covers more than 20,000 square kilometers.Geologically, it is composed in the eastern part by thick LowerCretaceous metamorphic rocks, and by Tertiary and Cretaceoussediments in the western part. Large deep-seated structuresaffecting the different stratigraphic units and related to tectonicevents in the Caribbean Block, are present in the region. Thedifferent metallogenic belts are located near the intersections ofthese deep-seated structures.The metallogenic zoning developed in the region ischaracterized, in the eastern part, by pyrite - chalcopyrite –pyrrhotite veins, affecting Lower Cretaceous metamorphic rocks.The central part hosts boulangerite, sphalerite, galena, tetrahedriteand arsenopyrite veins, and the western zone is typified by cinnabarveins in Tertiary sediments.Apparently, metallogenic zoning is closely associated with deep-seated structures. Mapping these structures constitutes animportant tool for outlining areas with different types of ore deposits.