朝鮮累層群 상부 캠브리아係 花折層에 挾在된 carbonate flat pebble conglomerate의 成因

• 영문명: Origin of carbonate flat pebble conglomerate of the upper Cambrian Hwajŏl formation, Chosŏn supergroup, Korea
• 발행기관: 대한자원환경지질학회
• 저자명: Byong Kwon Park(朴炳權) Sang Joon Han(韓相俊)
• 간행물 정보: 『자원환경지질』18권 2호, 177~187쪽, 전체 11쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1985.04.30

영문 초록

The carbonate flat pebble conglomerates (CFPC) are interbedded as lenticular bed in the greenish rhythmite of the upper part of Hwajŏl Formation, Josŏn Supergroup. Pebbles are composed mainly of lime-mudstone with small amounts of bioclasts and silt-sized subangular quartz grains. The matrix among pebbles is composed mainly of sparry calcite with relatively much amounts of bioclasts, silt-sized subangular quartz grains and authigenic pyrite crystals or grains. The sparry calcite of the matrix seems to be the results of neomorphism of skeletal sands and bioclasts. The pebbles are well rounded and no plastic deformations are found. Some pebbles show the outer rim of glauconite. CFPC are not associated with any other intertidal features such as stromatolites, flaser bedding and channel structures. Also any features indicative of subaerial exposure such as dessication cracks, fenestrae and so on are not found in the bed. The sedimentological features of CFPC suggest that the following conditions appear to have been necessary for the formation of CFPC : 1) episodic deposition of thin, permeable calcareous beds separated argillaceous beds; 2) preservation of these beds near the sediment-water interface where they could become rapidly cemented; 3) erosion and redeposition of the partially lithified beds by storms or other exceptional erosional events. Eventually storm erosion and redeposition together represent only one of several critical conditions in the genesis of CFPC. The CFPC are very common in Cambrian and lower Ordovician formations, and become very rare in the younger carbonate formations. The expansion of infauna after Ordovician Period eliminated the widespread potential for rapid submarine cementation which is one of the critical factors to form CFPC.

목차

Abstract

序言

硏究方法 및 材料

花折層의 CFPC

討議

結論

參考文獻