Tectonic Control Over Emerald Mineralization in Swat
Abstract
Emerald and chromian tourmaline occur in carbonate-talc/serpentine/chlorite rocks, carbonate-bearing talc schists, and associated quartz veins near Mingora, Charbagh, and Shangla. The rocks are altered ultramafic found in a discontinuous belt of volcanic, volcano-sedimentary, and sedimentary rocks that have undergone high P- low T metamorphism. The belt is a thrust slice overlying Gondwanic sialic metasediments and underlying the Kohistan (? oceanic) amphibolites both of which display Barrovian metamorphism in the almandine amphibolite facies. It appears that the emerald-bearing belt represents a marginal basin or trench rocks of (?) Mesozoic age with tectonically incorporated lenses of ultramafic rocks from the upper mantle.
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