准噶尔盆地车排子凸起新近系沙湾组重矿物、U-Pb年代学特征及物源分析  

Heavy Minerals Characteristics,U-Pb Geochronology and Provenance Analysis of Neogene Shawan Formation in Chepaizi Uplift,Junggar Basin

作　　者：李严 吴朝东[1,2] 张学才 谢利华 冷佳宣[1,2] 关旭同 LI Yan;WU Chaodong;ZHANG Xuecai;XIE Lihua;LENG Jiaxuan;GUAN Xutong(Key Laboratory of Orogenic Belts and Crustal Evolution,MOE,Peking University,Beijing 100871;Institute of Oil&Gas,Peking University,Beijing 100871;Manage Center of Oil and Gas Exploration of Shengli Oilfield Company,Sinopec,Dongying 257000)

机构地区：[1]北京大学造山带与地壳演化教育部重点实验室,北京100871 [2]北京大学石油与天然气研究中心,北京100871 [3]中国石油化工股份有限公司胜利油田分公司油气勘探管理中心,东营257000

出　　处：《北京大学学报（自然科学版）》2021年第6期1058-1070,共13页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家重大科技专项(2017ZX05008-001)资助。

摘　　要：综合岩石学特征、砂岩碎屑组分特征、重矿物组合特征和锆石U-Pb年代学特征,探讨准噶尔盆地车排子凸起新近系沙湾组沙一段的沉积特征和物源演化过程。结果表明,车排子凸起存在南北双物源体系,沙一段以粗碎屑沉积为主。在一砂组沉积阶段,扎依尔山为北部物源区,发育小规模扇三角洲沉积;中天山及北天山造山带为南部物源区,发育辫状河三角洲沉积。在二砂组沉积阶段,中天山供给减弱,北天山供给加强,盆地水体加深,南部辫状河三角洲前端分布小型滨浅湖滩坝。南部物源变化的主要原因可能是受印度板块和欧亚板块碰撞的远程影响,天山在新生代中新世中期经历强烈的挤压和抬升过程,造成北天山隆升,为车排子凸起提供物源。Based on the petrological characteristics,sandstone detrital composition,analysis of heavy minerals assemblages and U-Pb zircon age,the sedimentary characteristics and provenance evolution of Sha 1 member of Neogene Shawan Formation in Chepaizi Uplift are discussed.The results show that there were double-provenance systems of north and south in Chepaizi Uplift and Sha 1 member of Shawan Formation was dominated by coarse clastic deposits.In the sedimentary period of first sand group of Sha 1 member,the Zaire Mountains was the northern provenance,with small-scale fan delta deposits.The Central Tianshan and North Tianshan orogenic belts were the southern provenances,with braided river delta deposits.In the sedimentary period of second sand group of Sha 1 member,the sediments derived from the Central Tianshan were weakened,while those from the North Tianshan were strengthened,and the water body of the basin was deepened.Small shore-lake beach bars were distributed in front of the southern braided river delta.The main reason for the variation of the provenance in the south may be that the Tianshan experienced a strong extrusion and uplift process in the middle Miocene due to the remote collision between the Indian plate and the Eurasian plate,resulting in the uplift of the North Tianshan,which provided the provenance for Chepaizi Uplift.

关 键 词：物源分析 沉积特征 沙湾组 车排子凸起 准噶尔盆地 

分 类 号：P618.13[天文地球—矿床学]