准噶尔盆地沙湾凹陷西斜坡二叠系佳木河组物源区构造背景分析  

Tectonic setting analysis of provenance area of the Permian Jiamuhe Formation on western slope of Shawan sag,Junggar Basin

作　　者：吴晨骁 姚宗全 德勒恰提·加娜塔依 邓高山 李天明 赫佳 刘宇 王小红 曙格拉·马哈西 WU Chenxiao;YAO Zongquan;DELEQIATI·Janatayi;DENG Gaoshan;LI Tianming;HAO Jia;LIU Yu;WANG Xiaohong;SHUGELA·Mahaxi(Research Institute of Exploration and Development,PetroChina Xinjiang Oilfield Company,Urumqi 830014,China;School of Geology and Mining Engineering,Xinjiang University,Urumqi 830047,China;Key Laboratory of Central Asian Orogenic Belts and Continental Dynamics,Urumqi 830047,China)

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,新疆乌鲁木齐830014 [2]新疆大学地质与矿业工程学院,新疆乌鲁木齐830047 [3]中亚造山带与大陆动力学重点实验室,新疆乌鲁木齐830047

出　　处：《古地理学报》2022年第6期1149-1161,共13页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金青年基金(编号:41902109);新疆维吾尔自治区天山青年计划(编号:2020Q064)联合资助。

摘　　要：准噶尔盆地沙湾凹陷西斜坡二叠系佳木河组物源体系一直备受争议,导致沉积体系“众说纷纭”。利用聚类分析、多维尺度分析及主成分分析等方法,对重矿物含量、微量元素进行分析,明确了沙湾凹陷西斜坡二叠系佳木河组砂砾岩碎屑颗粒富石英(35.41%)、长石(43.2%),贫岩屑(18.71%)。稀土元素总量(ΣREE)平均值139×10接近大陆上地壳(UCC)的平均值148.14×10,Hf-La/Th微量元素物源判别图解和La/Sc-Co/Th值表明佳木河组属于酸性岛弧区。稀土配分模式表现为右倾分布模式,整体上具有“轻稀土元素富集、重稀土元素亏损”的特征,指示源岩以长英质火山岩为主,即“一源”。在同一物源下,又可以分为4个物源区:新光1井—中佳6井物源区,车排10井—中佳5井—中佳4井—中佳3井物源区,车排7井—车排005井体系物源区,车排5井物源区,即“四区”。构造背景判别图解揭示了佳木河组形成于大陆岛弧环境。该研究将有助于对沙湾凹陷西斜坡的沉积体系及古水系的准确恢复和远景区油气储集层的准确预测。It is very controversial on the provenance system and the depositional system of the Permian Jiamuhe Formation in Shawan sag of the Junggar Basin. In this paper, cluster analysis, multidimensional scaling analysis and principal component analysis were used to analyze the contents of heavy minerals and trace elements, and it was found that it is rich in quartz(35.41%),feldspar(43.2%)and poor in rock debris(18.71%)of conglomerate clastic particles in Permian Jiamuhe Formation in Shawan sag. The average value of rare elements equal 139×10,which is close to the average value in the continental upper crust(i.e.,148.14×10),the diagram of Hf-La/Th and La/Sc-Co/Th ratio indicate that the Jiamuhe Formation belongs to the acidic island arc region. The distribution pattern of REE shows a right-leaning distribution pattern, which is characterized as rich in LREE and poor in HREE,indicating that the source rocks are mainly feldspathic volcanic rocks. There are four provenance areas including Wells XG1-ZJ6 area, Wells CP10-ZH4-ZJ3 area, Wells CP10-CP005-CP26 area, and Well CP5 area. The discriminant diagram of tectonic setting reveals that the Jiamuhe Formation was formed in continental island arc environment. This study will be helpful for the reliable estimation of sedimentary system and ancient river system of the western slope area in Shawan sag and the accurate prediction of oil and gas reservoirs in prospective areas.

关 键 词：重矿物组合 微量元素 聚类分析 多维尺度分析 佳木河组 二叠系 沙湾凹陷 准噶尔盆地 

分 类 号：P595[天文地球—地球化学]