四川前陆盆地上三叠统须家河组物源区分析及其地质意义  

Provenance Analysis of Xujiahe Formation of Upper Triassic in Sichuan Foreland Basin and Its Geology Implications

作　　者：戴朝成[1,2] 郑荣才[2] 任军平[3] 朱如凯[4] 

机构地区：[1]东华理工大学地球科学学院,南昌330000 [2]成都理工大学油气藏地质及开发工程国家重点实验室,成都610059 [3]天津地质矿产研究所,天津300170 [4]中国石油勘探开发研究院油气储层重点实验室,北京100083

出　　处：《吉林大学学报（地球科学版）》2014年第4期1085-1096,共12页Journal of Jilin University：Earth Science Edition

基　　金：国家重大专项(2008ZX05000-003-01);东华理工大学博士基金项目(DHBK201118)

摘　　要：为了深入认识四川前陆盆地须家河组沉积物源方向及物源区构造背景,对该盆地次级构造单元内须家河组砂岩碎屑组分、岩屑类型、重矿物组合特征、稀土元素和微量元素进行了分析。结果表明,盆地中的碎屑物源主要来自再旋回造山带,部分可能来自造山之前的混合区,不同的构造单元和层位存在不同物源区的特点:川西坳陷物源主要受龙门山逆冲推覆带控制;川东北坳陷物源主要受米仓山—大巴山逆冲推覆带控制;川东南坳陷物源受雪峰古陆控制,而川中古隆起物源则主要来自南部峨眉瓦山古陆。物源区具有大陆边缘向大陆岛弧转化的构造演化特点,须四期龙门山的逆冲推覆活动明显强于须二期。Through the analysis of sandstone clastic composition, debris types, heavy mineral assemblages,REE and trace elements of Xujiahe Formation in Sichuan foreland basin secondary structure unit,the authors studied the provenance and tectonic setting of Xujiahe Formation sediments in Sichuan foreland basin.The results indicate that most of the clastic materials were derived from the orogenic recycle belt,some of them maybe come from the mixed area before the orogenesis,different tectonic units and strata exist different provenance：the provenance of west Sichuan depression is controlled by Longmen mountain thrust nappe belt,the provenance of northeast Sichuan depression is＆amp;nbsp;controlled by Micang Daba mountain thrust nappe belt,the provenance of southeast Sichuan depression is controlled by Xuefeng old land,while the provenance of medieval Sichuan uplift is controlled by the southern Emei archicontinent.Tectonic evolution characteristics of source area appear from a continental margin transform to the continental island arc,and Longmenshan thrust nappe activity in Xujiahe fourth phase is more stronger than Xujiahe second phase.

关 键 词：四川前陆盆地 上三叠统须家河组 物源分析 碎屑成分 重矿物 稀土元素和微量元素 

分 类 号：P618.13[天文地球—矿床学]