慶南 咸陽地域에 分布하는 火成岩類에 對한 岩石地化學的 硏究

Petrochemical study on igneous rocks in the Hamyang area, Kyongnam, Korea

Igneous rocks of the Hamyang area consist of Hamyang foliated granites and hornblende diorite. Hamyang foliated granites are classified into four rock types in terms of mineral composition and texture. The four rock types are foliated hornblende biotite granodiorite, foliated porphrytic granodiorite, foliated fine biotite granodiorite and foliated leuco granite. Petrochemical data of these rocks suggest that Hamyang foliated granites is calc-alkali rock series of differentiated products of cogenetic magma by fractional crystallization. Igneous rocks of studied area correspond to I-type, peraluminous and calc alkali rock series. Rb-Sr age and Sr⁸⁷/Sr⁸⁶ initial ratio for foliated prophrytic granodiorite is 200±Ma and 0.711±0.0037, respectively. K-Ar(hornblende) age of hornblende diorite is 179±9Ma. These data come to an coincidence with Igneous activity of South Korea which were proposed by O. J. Kim(1975), that is, they correspond to Hamyang foliated granites of products of Songrim Disturbance, and to hornblende diorite of Daebo Orogeny.