GEOLOGICAL, MINERALOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE CARLES GOLD MINERALIZATION, ASTURIAS, SPAIN

In the western part of the Cantabrian Zone, Carles gold mineralization is related to an igneous stock of granodioritic composition which intruded into devonian limestones, forming a well-developed exo-skarn and quantitatively less important endo-skarn. The skarn is characterized by the presence of garnet, pyroxenes, amphiboles, layers of hornfels corresponding to pelitic intercalations, and a number of opaque oxides and sulfides. Gold inclusions in arsenic minerals are present in quartz-veins occurring in the skarn and in the granodiorite, but gold-rich zones are limited to the skarn. The crystallization temperature of arsenopyrite is coherent with T-P conditions (T = 460-degrees-C, P = 2200 bars) deduced from intersections of isochores of aqueous and carbonic fluid inclusions studied in samples of cogenetic quartz.