Investigation of Malachite Formations on Horseshoe Island (West Antarctica)
Abstract
This study examines the occurrence of malachite in gabbro rocks on Horseshoe Island in the West Antarctic Peninsula. As part of the TÜBİTAK project no. 121Y357, samples were collected during the TAE-6 expedition in 2022 and subjected to petrographic analysis, mineralogical observations, and whole-rock geochemical study. The results suggest that malachite formation is directly linked to hydrothermal alteration zones, particularly occurring as vein or coating structures within the fractures and cavities of the gabbroic host rocks. Geochemical analyses revealed elevated concentrations of cupper (Cu) and iron (Fe), supporting the idea that malachite formed through the oxidation of sulfide-bearing copper minerals. These findings suggest the development of low-temperature hydrothermal systems influenced by post-magmatic processes, reflecting the characteristics of the late -stages of continental arc magmatism widely observed along the Antarctica Peninsula. The malachite formations on Horseshoe Island are an important indicator that contributes to our understanding of the tectonic and magmatic evolution of the region
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