Mineralizaciones de magnetita asociadas a skarns y bandas de cizalla: La mina de Cala (Huelva)

The Cala iron deposit has been traditionally regarded as a classic iron skarn developed on Cambrian limestone adjacent to a Variscan monzogranitic stock. Ongoing studies show that the geologic setting is more complex and the mineralization is replacive on marble and calcsilicate and pelitic hornfels and controlled by syntectonic hydrothermal activity with a pull-apart structure. The skarn only forms a part of the hydrothermal alteration. Most of the magnetite is related to an biotite-quartz-ankerite-chlorite assemblage, while the pyrite-chalcopyrite ore seems to be slightly younger, replacing magnetite along extensional structures, sharing many features with the IOCG style of mineralization.