摘要：

准噶尔盆地夏盐凸起石南31井区下白垩统清水河组为1套砂泥岩互层沉积，前人关于清一段沉积相和物源方向的研究成果较少。通过岩心观察和描述以及岩屑录井、分析化验资料的综合研究，从碎屑百分含量、砾岩厚度分布以及锆石-电气石-金红石指数（ZTR指数）、泥岩颜色分区等方面对物源方向进行了判断。综合分析表明：石南31井区清一段沉积时期的物源不是单一方向的，而是随时间推移，物源方向有所变化。碎屑百分含量分析发现清水河组一段第二砂层组第1砂层（K1q 2-11）和清水河组一段第一砂层组第3砂层（K1q 1-31）沉积时期的物源主要来自东南方和北方；清水河组一段第一砂层组第1砂层（K1q1-11）沉积时期物源方向发生了重大变化：东南方的物源消失，物源的变化主要是由于清一段晚期地层发生掀斜运动，导致古地理面貌由早期的南高北低变为北高南低。砾岩的厚度分布、重矿物ZTR指数分析及泥岩颜色分区也反映了相似的特征。综上所述，石南31井区在清一段沉积时期主要存在两个方向的物源：一为东南方向，一为北方，而且在一定时期，两个方向的物源各有一定的影响范围。由早到晚，北方物源由北向南逐渐深入，到晚期影响了整个研究区，早期东南方物源也为主要物源，到晚期退出了研究区范围。

Abstract:

The Lower Cretaceous Qingshuihe Formation in SN 31 well area in the Xiayan uplift of Junggar Basin is dominated by a set of interbedded sandstones and mudstones. Prior to this investigation, few studies had been carried out on the sedimentary facies and provenances. Based on the core observations，logging curves and analytical and testing data，the provenance was determined according to the clastic content，the thickness distribution of conglomerates，heavy mineral ZTR index and mudstone color zoningThe results show that the provenance during the deposition of the Member 1 of the Qingshuihe Formation in SN 31 well area is not a single one，while it   changed with time. The clastic content of the No1 interval  of the second sand zone of Member 1 of Qingshuihe Formation and the No3 interval  of the first sand zone indicated that the sediments were mainly derived from the southeastern and the northern provenances. During the deposition of the No1 interval  of the first sand zone，the provenance changed greatly. The southeastern provenance disappeared and its disappearance was mainly due to the tectonic movements during the late depositional period of the Member 1 of Qingshuihe Formation, which led to the topography changing from the earlier south higher and north lower topography to the north higher and south lower topography. The thickness distribution of conglomerates and heavy mineral ZTR index analyses also show similar characteristics. During the deposition of the Member 1 of Qingshuihe Formation，two main provenances existed in SN 31 well area. One is the southeastern source area and the other is the northern one. The two provenances had their own affecting regions. The impact of the northern provenance gradually increased and dominated the whole study area in the late period，while the southeastern provenance mainly had its controlling influence in the early period and disappeared in late period.