浦港盆地에 分布하는 延日層群의 古地磁氣 硏究

• 영문명: Paleomagnetic study of the Yeonil group in Pohang basin
• 발행기관: 대한자원환경지질학회
• 저자명: 김광호(Kwang Ho Kim) 도성재(Seong Jae Doh) 황창수(Chang Soo Hwang) 임동성(Dong Seong Lim)
• 간행물 정보: 『자원환경지질』26권 4호, 507~518쪽, 전체 12쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1993.08.30

영문 초록

Paleomagnetic investigations have been carried out on the Tertiary sedimentary formations (Yeonil Group) in Pohang basin, southeastern Korea. A total of 215 samples were collected from 26 sites. Progressive thermal demagnetization indicates that many samples have unstable magnetization and do not reveal a characteristic direction. However, some samples from the lower and upper Duho Formation show a characteristic direction D/I=7.8°/48.3° (α95=3.7°, κ=174.1). Stepwise thermal demagnetization data show that some samples from the Hagjeon and middle Duho Formations reveal great-circle distributions moving from the present to a reversed direction of geomagnetic field. The mean of intersection points of the great-circles is nearly antipodal to the characteristic normal direction of the lower and upper Duho Formation. We infer that the Hagjeon Formation was formed during the reversed polarity chron C5B (16.2~14.7 Ma) and the Duho Formation 14.7~11.6 Ma based on our results and previous paleontologic and age dating data. Paleomagnetic direction for the Middle Miocene of Korea, analysed from the combined results of stable endpoints and great circles, is D/I=8.7°/53.9° (α95=4.2°, κ=74.8), and the corresponding paleopole is Lat./Long.= 82.7°/230.2° (δp=2.8°, δm=5.9°). On the basis of this, we interpret that the opening of the East sea (Japan sea) or the synchronous clockwise rotation of the Southwest Japan exerted no structural influence on the Yeonil Group in the Middle Miocene.

목차

ABSTRACT

서언

지질 및 시료채취

고지자기측정 및 결과

암석자기 측정 및 결과

논의

결론

참고문헌