【摘要】 新疆克拉美利山南麓西大沟二叠系平地泉组,按其沉积特征划分为扇三角洲沉积。它具有三带结构,即:①扇三角洲平原,以瓣状河流及席状洪流沉积为主,是冲积扇体系的一部分;②扇三角洲前缘,包括水下分支河道、河道间沉积及滨岸和席状砂沉积;③前扇三角洲,主要由泥岩和粉砂岩组成。整个剖面可划分为8个大的正旋回,各旋回又由许多小的正、反韵律层序组成。更多还原

【Abstract】 The Pingdiquan Group in Xidagou area,according to its sedimentary features,is classified as fan-delta sedi-ments. The Xidagou fan-delta have following three member structure: ①)fan-delta plain, a part of alluvial system,consists mainly of braided stream and sheet-like-flooding sediments; ②fan-delta front,including underwater dis-tributary channel,inter-channel,shoreline and sheet-like sand sediments ; ③pro-delta consists mainly of clays andsilts. The entire profile can be divided into eight positive (fining-upward) cyclothems,and each of them in turnconsists of many secondary positive and negative rhythm sequences.更多还原