楊平火成 複合體에 對한 岩石學的 硏究

• 영문명: Petrology and petrochemistry of the Yangpyeong igneous complex
• 발행기관: 대한자원환경지질학회
• 저자명: Dai Sung Lee(李大聲) Yong Jun Kim(金勇俊)
• 간행물 정보: 『자원환경지질』7권 3호, 123~145쪽, 전체 23쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1974.09.30

영문 초록

The study focused to the so called “Yangpyeong Igneous Complex” which intruded into the Gyeong Gi gneiss complex of Pre-cambrian basement of Yangpyeong area. The geologic sequence of the mapped area was shown in table I. In laboratory work, 31 modal analyses and 7 chemical analyses on the rock samples taken from the igneous complex have been made to discuss the nomenclature of the rocks and the petrological relationship between rock types. The petrographical and petrochemical features based on the analyses are as follow: 1) The classification of this rocks based on the systematics of igneous rocks of JUGS showed that Yangpyeong Igneous complex consist of hornblende gabbro, diorite and porphyritic monzonite. The major rock forming minerals in hornblende gabbro are hornblende and plagioclase(An46~55), in diorite, hornblende, biotite and plagioclase (An23~33) and in porphyritic monzonite, K-feldspar, plagioclase (An21~35), hornblende and biotite. Hornblende gabbro and diorite show coarse to medium grained hypidiomorphic granular texture and porphyritic monzonite was named by the characteristically porphyritic texture of K-feldspar phenocrysts. 2) Silica-oxides variation diagram (Fig.4) illustrate that the igneous complex is similar to that of Daly’s average basalt-andesite-dacite-rhyolite and equivalent to the calc-alkalic rock series of Peacock’s rock series. In AMF diagram (Fig. 5), the trend of the igneous complex is nearly pararell to that of the Skaergaard intrusion which shows the trend of the fractional crystalization of magma. 3) In normative Or-Ab-An diagram (Fig. 6) the general trend of the data points from gabbro to porphyritic monzonite of the igneous complex directs to a point of Or/Ab=1:1 on the side of Or-Ab. The field and laboratory evidences suggested that the Yangpyeong igneous complex was thought to be a series of comagmatic differential products.

목차

Abstract

1. 序論

2. 地質槪要

3. 岩石各論

4. 化學成分

5. 論議

6. 結言

Reference