Petrology, geochronology and tectonic implications of Mesozoic high Ba–Sr granites in the Haemi area, Hongseong Belt, South Korea |
| |
Authors: | Seon-Gyu Choi V J Rajesh Jieun Seo Jung-Woo Park Chang-Whan Oh Sang-Joon Pak and Sung-Won Kim |
| |
Institution: | Department of Earth and Environmental Sciences, Korea University, Seoul 136 701,;Department of Earth and Environmental Sciences, Chonbuk National University Chonju 561 756, and;Energy Resources and Technology Research Institute, Chosun University, Gwangju 501 759, South Korea |
| |
Abstract: | Collision between the North and South China continental blocks began in the Korean peninsula during the Permian (290–260 Ma). The Haemi area in the Hongseong collision belt (proposed as the eastern extension in South Korea of the Dabie–Sulu collision zone of China) within the Gyeonggi Massif comprises post-collisional high Ba–Sr granite with intermediate enclaves that intruded into the Precambrian rocks. The intermediate enclaves have a shoshonitic affinity whereas the granite is a high-K calc-alkaline variety. The chondrite-normalized rare earth element (REE) pattern with relative enrichment of LREE over HREE and absence of a significant negative Eu anomaly typifies both enclaves and granite. Geochemical similarities of enclaves and granite are attributed to the involvement of enriched mantle sources in their genesis. However, dominant crustal components were involved in the formation of high Ba–Sr granites. A granite crystallization age of 233 ± 2 Ma was obtained from SHRIMP U–Pb zircon dating. This age is slightly younger than the Triassic collision event in the Hongseong Belt. Geochemical data, U–Pb zircon age, and regional tectonics indicate that the Haemi high Ba–Sr granite formed in a post-collisional tectonic environment. A Mesozoic post-collisional lithospheric delamination model can account for the genesis of high Ba–Sr granite in the Haemi area. |
| |
Keywords: | High Ba-Sr granite post-collisional lithospheric delamination Haemi Hongseong Belt Dabie–Sulu |
|
|