Pretectonic and posttectonic emplacements of the granitoids in the south central Okchon belt, South Korea: Implications for the timing of strike‐slip shearing and thrusting

Temperature and Timing of the Mylonitization of the Leucocratic Granite in the Northeastern Flank of the Taebaeksan Basin

“…Because the shear zone predates intrusion of the Boeun granitoid (ca. 172 Ma; Ree et al, 2001). Multiple shear movements also preserved in the Jeonju-Muan and Yecheon shear zones (Fig.…”

“…The Honamshear zone mainly developed around the tectonic boundaries between the Yeongnam massif and the Okcheon Basin (e.g., Sunchang, Cheongsan, and Yecheon shear zones; Cho et al, 1999;Cheong et al, 2006;Cho et al, 2007) and within the Okcheon Basin (Jeonju-Muan shear zones; Lee et al, 2001;Lee et al, 2003;Kim et al, 2003;Park et al, 2009). These shear zones are dominantly characterized by right lateral strike-slip movement of ductile or brittle-ductile shearing (Kim and Kee, 1994;Lee, 1996a, 1996b;Chough et al, 2000;Ree et al, 2001). Cluzel et al (1991) suggested that the shear zones are amalgamated during the Triassic associated with the Chinese continental collision.…”

“…11; Ree et al, 2001). Ree et al (2001) suggested that the Cheongsan shear zone is transform fault boundary generated from juxtaposition of the South China Block (involving Okcheon Basin and Gyeonggi massif) and North China Block (involving the Taebaeksan Basin and Yeongnam massif) during a late stage of the Middle Triassic Songrim orogeny. However, another interpretation for the mylonitization timing is that the Cheongsan shear zone can be developed during the Early to Middle Jurassic (Fig.…”

“…1). The Honam shear zone is characterized by a dextral strike-slip shear zone and mainly developed around the Okcheon belt and the Yeongnam massif (Kim and Kee, 1994;Lee 1996a, 1996b;Cho et al, 1999;Ree et al, 2001Ree et al, , 2005Cheong et al, 2006;Kim et al, 2009;Park et al, 2009). Yin and Nie (1993) suggested that the dextral strike-slip shear zone developed during the middle-late Triassic Songrim orogeny associated with collision between the North and South China Blocks (e.g., Yanai et al, 1985).…”

“…Yin and Nie (1993) suggested that the dextral strike-slip shear zone developed during the middle-late Triassic Songrim orogeny associated with collision between the North and South China Blocks (e.g., Yanai et al, 1985). However, recent radiometric age data and structural evidence indicate that the multiple strike-slip shear movements along the Honam shear zone occurred during the Middle Jurassic to the Early Cretaceous (Turek and Kim, 1995;Cho et al, 1999;Ree et al, 2001;Cheong et al, 2006;). Thus, the Honam shear zone is not the Permian to Triassic tectonic features related to the Chinese collision (Cheong et al, 2006;Kim et al, 2009).…”