上部 沃川層 의 巖石學的 및 地構造的 解釋 에 關한 硏究

• 영문명: Study on Lithologic and Tectonic Interpretation of the Upper Okcheon Members
• 발행기관: 대한자원환경지질학회
• 저자명: Ok Joon Kim(金玉準) Jeong Su Yoon(尹正守)
• 간행물 정보: 『자원환경지질』13권 2호, 91~103쪽, 전체 13쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1980.06.30

영문 초록

In spite of the fact that the Okcheon system has been rather intensively studied by many geologists since 1945, it still remains as a controversal problem as to its stratigraphy and geologic age. Present study has mainly focused on the upper members of the Okcheon system, namely the Hwanggangri and the Kunjasan formations so as to clarify the lithology, the depositional environment and the tectonic evolution of the formations. The Kunjasan formation lying unconformably over the Hwanggangri formation which is supposed to be a meta-tillite is interpreted as a metamorphosed calcareous argillaceous and/or arenaceous sediments on contract to the idea postulated by some geologists that it was a derivative of silicified Hwanggangri formation. Lithology of the Kunjasan and the Hwanggangri formation is quite different in that the former is white in color, contains few pebbles, and mostly composed of diopside and detrital quartz, whereas the latter is black to dark in color, contains abundant and variable kinds of pebbles, and composed of more argillacous matrix that has been metamorphosed to hornfels. The Hwanggangri and the Kunjasan formations were deposited in the rather deep sea which has transgressed toward northeast from southwest in the late Precambrian time, and the writer (1970) had formerly designated it as Okcheon Paleogeosyncline. With the beginning of Paleozoic era, Okcheon neogeogyncline was formed to the northeast of the old paleogeogyncline area. The transgression of the sea had proceeded toward southwest in which Cambrian strata were accumulated. During this period the area occupied formerly by the paleogeosyncline was uplifted, so that most of the Hwanggangri and the Kunjasan formations were eroded away except in the area close to the neogeosyncline sea coast. This is the reason why the Hwanggangri and the Kunjasan formations are cropped out presently in the area of the vicinity of contact zone of the paleo- and neogeosyncline zones. The age of the Okcheon system has been reconfirmed to be Precambrian from the view of the facts that 1) the Hanggangri formation, the upper member of the Okcheon system is meta-tillite and correlated to the Precambrian tillite in the Yantze basin in China, 2) the Okcheon system has been moderately metamorphosed while other formations of the same age, if it is Paleozoic or later, have not been metamorphosed, and 3) tectonic history and limited areal distribution of the Hwanggangri and the Kunjasan formations is suggestive of Precambian age.

목차

Abstract

1. 序論

2. 本硏究가 지니는 意義

3. 沃川系 硏究의 綜合과 討論

4. 今般 調査硏究의 綜合

5. 結論

References