Early to Middle Paleozoic arc magmatism in the Korean Peninsula: Constraints from zircon geochronology and geochemistry

The Hongseong area of the central southwestern Korean Peninsula has been tectonically correlated to the Qinling-Dabie-Sulu collisional belt of the central China Orogenic Belt. Here we have presented geochemical and sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon data on the metaigneous rocks from the Early to Middle Paleozoic Gwangcheon gneiss, located in the middle of the Hongseong area. Our data show U-Pb ages of ca. 450. Ma for quartz-dioritic gneiss, 442. Ma for metagabbro, 409, 407 and 402. Ma for tonalitic gneiss, 440. Ma for intermediate dyke, and 401. Ma for mafic intrusive. The rocks display geochemical features suggesting magma generation within Late Ordovician (ca. 450. Ma) to Early Devonian (ca. 401. Ma) subduction-related volcanic arc and subsequent collapsing environment. The ages and geochemical characteristics presented in this study correlate well with those of the Early to Middle Paleozoic orogenic belts in the Qinling orogenic belt. Our study provides further insights into the tectonic linkage among Paleozoic to Triassic East Asian continents, with evidence for a Paleozoic Pacific-type subduction prior to the Triassic Alpine-type collision.