경남 양산 원동칼데라 중앙부의 각섬석-흑운모 화강암에 나타나는 포획암의 기원

• 발행기관: 대한자원환경지질학회
• 저자명: 김춘식 김성욱 김근수 김국락 손문 김종선
• 간행물 정보: 『자원환경지질』32권 4호, 339~351쪽, 전체 13쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1999.08.30

영문 초록

Petrographic and palaeomagnetic studies have been conducted to understand the origin of dark-colored enclaves occurring in the hornblende biotite granite within the Wondong caldera. The enclaves are commonly elongted and rounded in shape. They are finer-grained and darker-colored than enclosing granite, but they have simliar mineral assemblage to that of granite. Under the microscope the enclaves show microstructures reflecting an igneius origin. The microstructures of igneous origin include elongate grain shapes of plagioclase, hornblende, apatite, poikilitic anhedral quartz and zoning of plagiclase. All above features indicate that the enclaves belong to the microgranitoid enclaves of Vernon (1984). a total of 91 orirnted samples were drilled from 4 sites, and their AMS (anisotropy of magnetic susceptibility) axis directions and remance components were analyzed. The result shows thar both enclave and host granite have same AMS priniciple axis direction and same remanence magnetic direction in each site. The result of this study suggests that the anclaves were derived from the globules of magma, which were formed by pillowing of synpltonic dike of magma that is more mafic than the host granite magma.

키워드

원동칼데라 각섬석 흑운모 화강암 암석기재학 고자기학 enclave xenolith 염기성포획체 집적암