摘要
庙岛群岛扼渤海之口,位于黄、渤两海交界处。作者等近年来对庙岛群岛的地貭情况进行过一些观测,其结果可能对于正确孰识群岛的地貭情况及推论渤海海峡的形成时代有所帮助,现提供于下,备今后在这个区域工作的同志参考。
The Miaodao Islands lie in the Pohai Strait and are of considerable importance in the studies of the formation of this strait.The geological history of Miaodao Islands is a history of the Pohai Strait itself.They consist of precambrian metamorphic rocks covered by Quaternary sediments.According to their contact relations and distributional positions,the Quaternary sediments may be divided into three groups in the following ascending order:1.Deposit of Changshan stage(Q_(Ch))It consists of red clay,of which part is weathered fragments of phyllit.2.Deposit of Heishan stage(Q_(h))It consists of loess formed in the upper Pleistocene age.Its colour is yellow with earthy red.In most part it is fossiliferous,but there remain some gastropoda and pelecypoda.These fauna are preliminarily identified as Ostrea denselamellosa Lischke,Chlorostoma argyrostoma umbilicata(Lischke),Turbo coronutus granulatus Gmelin,Monodonta labio(Linne).The formation of loess indicates seashore or estuary phases.3.Deposit of Miaodao Islands stage(Q_(m))It consists of diluvial and eluvial deposits of Holocene age with recent sediments of sea shore or estuary.Hence,from the view-point mentioned above,a primary result indicates that Miaodao Islands projected out persistently above the sea level from late Precambrian without remains of any sediments until the late Pleistocene.They were submerged by sea water,and the widespreaded loess was deposited on them at the same time.Islands rose above the sea level again in Holocene age.The present Pohai Strait may be considered as being formed in late Pleistocene or early Holocene.
作者
金翔龙
郑开云
JIN XIANG-LONG;ZENG KAI-YUN(Institute of Oceanology,Academia Sinica)
出处
《海洋与湖沼》
1964年第4期364-370,共7页
Oceanologia Et Limnologia Sinica
