江南造山带西段冷家溪群沉积地质特征及构造属性探讨  

A discussion on the sedimentary characteristics and structural properties of Lengjiaxi Group in the west part of Jiangnan orogenic belt

作　　者：张恒[1,2] 谢莹 张传恒[2] 李廷栋[1] 耿树方[1] 高林志[1] 游国庆[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质大学(北京),北京100083 [3]中国石油华北油田公司石油勘探开发研究院,河北任丘062552

出　　处：《地学前缘》2013年第6期269-281,共13页Earth Science Frontiers

基　　金：中国地调局工作项目(1212011120117);国家油气重大专项(2011ZX05043-005);国家自然科学基金项目(40921062)

摘　　要：江南造山带西段的重要组成部分冷家溪群中可识别出浊积岩相、深海相两种类型沉积相,属活动类型沉积建造。临湘地区冷家溪群的沉积物扩散指向南,物源应来自北方的古老基底;而沅陵地区冷家溪群的沉积物扩散指向东或东北方向,物源应来自西或西南方向古老基底。沉积岩骨架颗粒统计结果表明,石英含量占44%~87%,且主要为单晶石英,而长石含量占5%~20%,岩屑含量占6%~42%,火山岩屑极少见,冷家溪群的物源为再旋回造山带。地球化学特征分析表明,冷家溪群形成的构造环境为活动大陆边缘。综合分析冷家溪群的物源、骨架颗粒特征及其构造环境,冷家溪群的原型盆地为周缘前陆盆地。The turbidite facies and deep sea facies can be identified from the Lengjiaxi Group,the important part of the west segment of Jiangnan orogenic belt.They belong to the active type of sedimentary formation.The sediment diffusing direction of the Lengjiaxi Group in Linxiang area is pointing southward,and its source should be the ancient basement in the north;the sediment diffusing direction of the Lengjiaxi Group in Yuanling area is pointing east-or northeastward,and its source should be the ancient basement in the west or southwest.Skeleton particle statistical results show that quartz adds up to 44%-87%,mainly single crystal quartz,and that feldspar adds up to 5%-20%,clast adds up to 6%-42%,and it is rare to see volcanic clast.The source of the Lengjiaxi Group is re-cyclic orogenic belt.The geochemical analysis also shows that Lengjiaxi Group＇s tectonic environment is active continental margin.By comprehensive analysis of Lengjiaxi Group＇s source,skeleton particles and tectonic environment,it is concluded that the basin prototype of the Lengjiaxi Group is the peripheral foreland basin.

关 键 词：冷家溪群 江南造山带 活动大陆边缘 周缘前陆盆地 

分 类 号：P588.2[天文地球—岩石学]