Global Distribution
UHT rocks are now identified in all major continents and span different geological ages ranging from c. 3178 to 35 million years associated with major geological events. More than 46 localities/terranes with diagnostic UHT indicators have been reported over the globe, related to both extensional and collisional tectonic environments; the two fundamental types of Earth orogenic systems. The major Archean UHT rocks are distributed in East-Antarctica, South Africa, Russia and Canada. Paleoproterozoic UHT granulites were reported from the North China Craton (during the accretion of the supercontinent Columbia), Taltson magmatic zone, northwestern Canada and South Harris, Lewisian complex, Scotland. UHT rocks from the Neoproterozoic Grenville orogeny are distributed in the Eastern Ghats Province, India. Neoproterozoic-Cambrian (Pan-African) UHT occurrences are mainly distributed in Lutzow-Holm Bay, East Antarctica, southern Madagascar, Sri Lanka and southern India UHT rocks are also reported from younger terranes like the Triassic Kontum Massif, Vietnam, Cretaceous Higo belt, Japan and Paleogene Gruf Complex, central Alps. Three million year old xenoliths erupted in Qiangtang imply that UHT metamorphism is ongoing beneath central Tibet.
Read more about this topic: Ultra-high-temperature Metamorphism
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