山东荣成成山头“柳夼红层”的层序、划分与成因及其气候意义(Ⅱ)

四、“柳夼红层”的物质组成 本文(Ⅰ)所列“柳夼红层”剖面地层层序进行了物相、粒度、X衍射和ESR年代测定,其结果与宏观观察结果相吻合。 “柳夼红层”,剖面序列,层位和时代有所不同,成因有别,而在物质组成上却大同小异,表现出从晚更新世早期至全新世地层,其物源供应基本相同,都来源于燕山期斑状花岗岩的风化破碎产物,属就地近源搬运。

THE SEQUENCE, DIVISION, GENESIS AND CLIMATIC IMPLICATION OF "LIUKUANG RED BEDS" IN CHENGSHANTOU, RONGCHENG COUNTY,SHANDONG PROVINCE

Liukuang red beds", the red-coloured strata which crop up on the north coast of Chengshntou, Rongcheng county, Shandong Province, bear no fossils. Debate has been continuing since 1960's on the genesis and age, and the sequence of strata has not been established yet. This paper illustrates the sequence and division of "Liukuang red beds" as well as the marks of palaeoenvironments in which the strata were formed. In addition, discussions are made about the composition and age of the strata. "Liukuang red beds" may be divided into two members. The upper member largely consists of a succession of cyclic deposits, namely the alternations of eolian deposits and pedogenic clay beds (soils), subordinate alluvial deposits being intercalated within the lower part. There are eight first-order boundary surfaces in the upper member, showing nine cold/warm climate cycles. The upper member, therefore, has a good geological record of the last glacial stage for the north coasts of China. The lower member, belonging to the record of last interglacial stage, is composed of pedogenic sandy clay beds which are distributed on the erosive surfaces of porphyritic granites formed during the Yanshanian stage. In "Liukuang red beds", the marks of environment for eolian deposits are clear and three orders of boundary surfaces also obvious, explaining the frequent alternations of cold and warm climates. Consequently, the strata are of significance for the division and comparison of climate stages of the last glacial age.