Structural Evolution of the Yuntai Mountain Area in Hunan Province: Implications for Sb-Au Exploration

The Yuntai Mountain area in Hunan Province represents a region of significant geological interest due to its position on the Western Hunan Sb-Au metallogenic belt. This area is characterized by distinctive geological structures formed through diverse tectonic activities spanning millions of years, and hosts important antimony and gold deposits. While hydrothermal fluids likely contributed to the formation of these mineral occurrences, the structural evolutionary pattern and its influence on mineralization remain inadequately understood. This study aims to reconstruct the structural evolutionary history of the Yuntai Mountain area. The research objectives are achieved through (a) conducting field geological surveys to identify the structural alignments (faults, fold patterns, shear zones, fractures, displacement markers, and lineations) formed during different deformation episodes within the Yuntai Mountain area’s strata and ore veins, (b) performing classical inversion analysis to categorize the episodes of structural deformation, and (c) correlating these deformation episodes with corresponding structural movements to clarify the region’s tectonic evolutionary pattern. Our findings reveal that the Yuntai Mountain area experienced four major tectonic events: (a) Early Paleozoic NW-SE compression, (b) Triassic NE-SW compression, (c) Jurassic NW-SE compression, and (d) Cretaceous NW-SE extension. Understanding this structural evolutionary pattern of the Yuntai Mountain area holds critical significance for guiding the future exploration of Sb-Au deposits throughout the region.