新疆柯坪地区二叠纪卡仑达尔组震积岩的发现及意义

Discovery and Geological Significance of Seismites of Permian Kalundaer Formation in Keping Area,Xinjiang

新疆柯坪地区二叠系卡伦达尔组岩性主要为灰绿色中-厚层细粒钙质砂岩、浅紫红色钙质粉砂岩、钙质粉砂质泥岩等,见交错层理、平行层理、透镜状层理,偶见波痕等沉积构造,具有滨浅海环境特征。局部发育多种软沉积变形构造,包括层间微断层、球枕构造、重荷膜与火焰状构造、液化泥岩脉等。根据沉积构造和沉积序列特征,推测本组沉积时主要为三角洲平原环境,软沉积变形构造可能由地震事件触发。

This paper mainly discusses the sedimentary characteristics,vertical sequence and geological significance of suspected seismites of Permian Kalundaer Formation in Keping area,Xinjiang.Lithology is mainly composed of interbedded medium-thick celadon fine calcareous sandstone,shallow purplish red calcareous siltstone and calcareous silty mudstone.Sedimentary structures such as cross beddings,parallel beddings,lenticular beddings and occasional ripple marks indicate the sedimentary environment of the offshore area.We found various soft-sediment deformation structures including interlaminar micro faults,seismic-related fractures,ball-and-pillow structures,load cast and flame structures,sandstone blocks and liquefied shale veins.According to sedimentary structures and characteristics of sedimentary sequence,we infer that Kalundaer Formation deposited in deltaic plain,and soft-sediment deformation structures are most probably triggered by seismic event.