灵山岛北端早白垩世复理石中的滑塌断崖  

Slump Scarp Outcrop Found in Early Cretaceous Flysch,North of Lingshan Island,Qingdao,Shandong

作　　者：董晓朋 吕洪波 张星 张海春[2,3] 王俊[4] 张素菁[4] 

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266580 [2]现代古生物学和地层学国家重点实验室,南京210008 [3]中国科学院南京地质古生物研究所,南京210008 [4]香港大学地球科学系

出　　处：《地质论评》2014年第4期771-779,共9页Geological Review

基　　金：现代古生物学和地层学国家重点实验室开放课题(编号0826060303)的成果

摘　　要：山东灵山岛北端背来石附近复理石为下白垩统灵山岛组(K1lsd)上段,笔者等在其野外露头上发现了海底滑塌侵蚀区的代表性构造——滑塌断崖。据野外观察,背来石附近复理石以含砾粗砂岩夹泥质粉砂岩为主,偶夹砾岩层。滑塌陡崖一般发育在事件沉积层——粗砂岩或含砾粗砂岩中,断面呈上凹的弧形,上覆继承性沉积了泥质粉砂岩或粉砂质泥岩。滑塌褶皱、震动液化脉等事件沉积普遍发育,说明灵山岛组沉积时地震频发。根据滑塌褶皱枢纽、轴面以及滑塌断崖产状判断滑塌方向有两个:主要为SW→NE,部分为S→N。滑塌断崖的发育揭示了:随着盆地的收缩变浅,灵山岛地区由纯粹的滑塌堆积区逐渐转变为滑塌侵蚀—堆积混合区,灵山岛组上段砂泥比增大且含大量片麻岩和石英岩砾石,说明沉积区更接近陆缘,盆地处于残余洋盆发育的晚期阶段。On the outcrop of flysch nearby Beilaishi （flying stone）,north of Lingshan Island,we recognized the typical structures of slump depletion zone-slump scarps.The flysch there belongs to the upper part of Lingshandao Formation （K1lsd）,which is mainly composed of coarse sandstone and pelitic sandstone,embedded with some conglomerate beds.Slump scarps were found in the event deposits-sandstone and pebbly sandstone beds.The pelitic sandstone or silty mudstone beds were cut by the slump surface concaving upward.Slump folds,liquefaction sand dikes and event deposits that are frequently outcropped in the flysch were speculated to be triggered by earthquakes.Attitudes of slump folds and scarps reveal the major slump direction,SW →NE,and the minor slump direction,S→N.Slump folds and scarps in the same section imply a transformation from pure slump accumulation zone to slump depletion-accumulation zone of this area in the Early Cretaceous.The sand-shale ratio of the upper part of Lingshandao Formation nearby Beilaishi （flying stone） is higher than that of the flysch in the Shipyard outcrop.Besides,many gneissose and quartzitic gravels are found in sandstone beds in the upper part of Lingshandao Formation.Therefore,the remnant basin was in its late stage with water shallowing upward during the sedimentation time.

关 键 词：山东青岛灵山岛 灵山岛组(K1lsd) 滑塌断崖 滑塌侵蚀—堆积混合区 残余盆地晚期 

分 类 号：P534.53[天文地球—古生物学与地层学]