SHRIMP U-Pb gcochronology of the Yunkal metamorphic complex in southeastern Guangxi, China

Highly precise zircon SHRIMP U-Pb dating was carried out on granitic gneiss in the Late Precambrian Yunkai metamorphic complex, garnet pyroxenite in the medium- and high-grade metamorphic Tiantangshan Group complex and mid-ocean ridge metabasic volcanic rocks (amphibolite) in the medium- and low-metamorphic Yunkai Group complex in the Yunkai area, Guangxi, southwestern Cathaysia. The data show the following ages: 1894±17 Ma and 1847±59 Ma for garnet pyroxenite of the Tiantangshan Group complex, indicating a Paleoproterozoic age; 1462±28 Ma for the metabasic volcanic rocks (amphibolite) of the Yunkai Group complex, indicating the presence of fragments of the Meso- and Neoproterozoic oceanic crust in the Yunkai area; 906±24 Ma for the granitic gneiss intrusion is, which should be the product of the global Grenville (Sibaoan) collisional orogeny occurring around 1000 Ma BP. In addition, an inherited detrital zircon age of 2702±13 Ma was also obtained, which is the oldest age in the Yunkai area and even in Cathaysia, proving the presence of Neoarchean continental crustal material in Cathaysia.