龙门山地区泥盆纪碳酸盐与硅质碎屑的混积相与混积机理  

HYBRID FACIES AND MECHANISM FOR THE FORMATION OF THE MIXED DEVONIAN CARBONATE SILICICLASTIC SEDIMENTS IN THE LONGMEN MOUNTAIN AREA,SICHUAN

作　　者：李祥辉[1] 刘文均[1] 郑荣才[1] 

机构地区：[1]成都理工学院沉积地质研究所

出　　处：《岩相古地理》1997年第3期1-10,共10页

基　　金："八五"国家基础性研究重大关键项目

摘　　要：碳酸盐与陆源碎屑的混合沉积研究至今尚未引起足够重视，文献屈指可数。扬子西缘龙门山地区泥盆纪发育了这类良好的混合沉积。作者根据实际材料，首次从这一思路出发，识别出该区泥盆纪Ｅｍｓｉａｎ期到Ｇｉｖｅｔｉａｎ早期的混积相四种，混积亚相约１４种，阐明了其优势混积作用；根据混积作用特征、沉积背景关系，划分出两大混积类型，即泥质背景下的混积Ⅰ型和砂灰质背景下的混积Ⅱ型；对混积作用机理进行了探讨；并指出不同级次的混积层序类型。Four hybrid facies and fourteen hybrid subfacies are recognized in the Emsian to early Givetian (Devonian) mixed siliciclastic-carbonate sediments from the frontal zone of the Longmen Mountain area,Sichuan on the westren Yangtze platform.They may be assigned, on the basis of hybrid processes and background sediments,to two types;the hybrid type Ⅰ sediments dominative of shelf shales controlled by punctuated mixing,in-situ mixing and source mixing,and the hybrid type Ⅱ sediments dominated by sandy and limy littoral and shallow shelf deposits. The authors contend that the punctuated mixing of the hybrid type I sediments is re- lated to the processes of storm wave and reflux,while the in-situ mixing has a connection with birth growth and death of biological communities after the storms ceased.The mixing of the main hybrid facies in the hybrid type Ⅰ sediments is in general governed by relative sea level fluctuations and the supply cycles of different orders are also discussed in the pre- sent paper.

关 键 词：泥盆纪 碳酸盐 硅质碎屑 混积相 岩石混合 

分 类 号：P588.245[天文地球—岩石学] P588.244[天文地球—地质学]