釜山直轄市 影島地域의 層序設定과 球狀岩에 關한 硏究

• 영문명: Stratigraphic Erection and Orbicular Rocks of the Yeongdo Island, Busan, Korea -With Emphasis on Orbicular-Tuff and-Hornfels-
• 발행기관: 대한자원환경지질학회
• 저자명: Haang Mook Kim(金恒黙 )
• 간행물 정보: 『자원환경지질』17권 4호, 299~314쪽, 전체 16쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1984.08.30

영문 초록

The Yeongdo Island in Busan City is a remnant of the latest Cretaceous volcano, and consists geologically of andesites, rhyolite tuff, pelitic and psammitic hornfelses, lapilli rhyodacite tuff of the Yucheon Group, felsite and felsite porphyry of the Bulgugsa intrusives, and Holocene sediments in ascending order. The hornfelses are bound to the Taejongdae Formation. The stratigraphic position of the Formation is determined definitely into the Yucheon Group, thus the geologic age is approximately the same with the volcanic rocks of the Group. The sediments had been thermally metamorphosed to make pelitic and psammitic hornfelses of the albite epidote hornfels facies by the effects of active hydrothermal circulation, vaporization, and hybridization of andesitic solution, or of basification of acidic intrusives. Thus, on occasion, those hornfelses are not used to be distinguished from the andesitic rocks in the southeastern part of the Korean peninsula. The paleocurrent direction determined from several cross-beddings of the Taejongdae Formation is suggested to be from southwest to northeast. Orbicular rocks occur in hornfelsed rhyolite tuff, pelitic- and psammitic-hornfelses, and felsite porphyry at a lot of outcrops in the area of southwestern shoreline of the Yeongdo Island. Orbicules in rhyolite tuff and hornfels in the island might have originated from diffusion processes of metasomatic metamorphism carried out by hydrothermal solution rised from the intrusive adamellite which may be emplaced deeply under the Yeongdo volcanics. Those orbicules are due to metasomatic, secondary, and epigenetic origin. Proto-, multi-shelled, and multi-cored orbicules are described in the orbicular tuff. But multi-cored orbicules are not found in the orbicular fornfels. 250 tuff-orbicules numbered sporadically are in 20,000m² area of the locality of orbicular tuff. About 60 hornfels-orbicules occurred sporadically are in 1,700m² area of the locality of orbicular hornfels in the Taejongdae Formation. Orbicules in felsite porphyry might have originated by diffusion reaction between xenoliths and a quiescent zone in felsite porphyry magma. Those are of igneous, primary, and syngenetic origin.

목차

Abstract

序言

層序設定

球狀岩의 確因

産出狀態

球狀岩의 鑛物

球狀岩의 化學組成

球狀岩의 成因

結論

參考文獻

Explanation of Plates