Resultados Preliminares de Anisotropia de Susceptibilidade Magnética e Mineralogia Magnética do Complexo Vulcânico Caviahue-Copahue (Argentina).

The petrofabric of igneous rocks is important to explore the flow dynamics of materials that formed them. In volcanic and pyroclastic rocks, the petrofabric reflects the directions in which lavas and pyroclasts flowed. Anisotropy of Magnetic Susceptibility (AMS) is a technique widely used to characterize the petrofabric of igneous rocks. However, recent studies show that this technique must be supported by a detailed mineralogical characterization to reduce the ambiguity in the interpretation. In this work, we present preliminary results of AMS and magnetic mineralogy in volcanic and pyroclastic rocks (ignimbrites) from Caviahue-Copahue Volcanic Complex (CCVC, Argentina). Results indicate that magnetic mineralogy strongly affects the AMS results in volcanic rocks and associated ignimbrites, providing “scattered” fabrics when late, Ti-rich titanomagnetite phases dominate the fabric; “inverse” or “intermediate” fabrics when single-domain grains are present, and “normal” fabrics when early crystalized pure magnetite is present.