Scandium mineralization associated with hydrothermal lazulite-quartz veins in the Lower Austroalpine Grobgneis complex, Eastern Alps, Austria

摘要

Lazulite (MgAl_2(PO_4)_2(OH)_2)-quartz veins within the Lower Austroalpine Grobgneis complex, Austria, have Sc-contents up to 200 ppm. The predominant Sc-carrier is pretulite, ScPO_4, and this phase occurs as a wide-spread accessory mineral. Vein formation took place at temperatures of 300-500℃ and low pressure during Permo-Triassic extensional tectonics and fluid flow. Mg-enriched alteration zones suggest that vein material was not derived from the immediate host rocks. Eo-Alpine metamorphism and deformation overprinted the veins to varying degrees. Despite the low tonnage of the Sc-rich veins, this new type of Sc-mineralization may point to larger Sc-accumulations in similar phosphate-rich hydrothermal environments.