Cenozoic Strike-Slip Displacement along the Yangsan Fault, Southeast Korean Peninsula

Abstract

Abstract Granitic rocks astride the Yangsan fault on the southeast Korean Peninsula can be classified into five rock types in two groups, based on field relationships and petrographic features. Group I rocks are granodiorite, enclave-rich porphyritic granite, and enclave-poor porphyritic granite. Mafic microgranular enclaves (MME) and/or mafic clots in rocks of this group imply magma mixing. Group II rocks are equigranular and micrographic granite indicative of shallow emplacement. Group II rocks intrude Group I rocks without magma mingling at several outcrops. The granitic rock facies on both sides of the Yangsan fault are similar, suggesting post-50 Ma dextral motion of approximately 21 km in a N20°E direction.