库车前陆盆地早白垩世岩石圈粘弹性变形的地层记录  

Stratigraphic Records on Lithospheric Viscoelastic Deformation in Early Cretaceous,Kuqa Foreland Basin

作　　者：王家豪[1,2] 王华[1] 云露 马慧明 尚亚乐[1] 

机构地区：[1]中国地质大学资源学院,武汉430074 [2]中国地质大学构造与油气资源教育部重点实验室,武汉430074 [3]中国石油化工股份有限责任公司西北油田分公司勘探开发研究院,乌鲁木齐830011

出　　处：《沉积学报》2010年第3期412-418,共7页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(批准号:40872077)资助

摘　　要：基于前陆盆地岩石圈弹性与粘弹性挠曲变形的不同特点,提出应用前隆斜坡带地层结构获取岩石圈力学性质及变形过程信息的思路。对库车前陆盆地的实例分析表明,研究区早白垩世历经了两个逆冲期至宁静期的构造演化,卡普沙良群、巴什基奇克组分别为逆冲期和宁静期的地层记录。在单个逆冲期,随着逆冲加载和岩石圈挠曲变形,岩石圈性质从弹性转化为粘弹性,盆地由向克拉通方向扩展变宽转变为向逆冲带变窄加深。相应地,前隆斜坡带的地层记录为:逆冲早期,地层向克拉通方向渐进超覆和退积;逆冲晚期,地层向逆冲带收缩和前积,形成底面上超/削截和顶面削截—顶超两个重大不整合面。宁静期盆地宽浅,地层平行连续,临近冲断带因岩石圈回弹产生少量削截不整合。Based on the flexural process of elastic lithosphere different from that of viscoelastic lithosphere in foreland basins,this paper provides a solution to acquire the information about lithospheric dynamic property and deformation process by virtue of stratigraphic configurations at the forebulge slope belt.The Kuqa foreland basin,as an example,had gone through tectonic evolution of two thrust period and a quiescence period in the Early Cretaceous.The Kapushaliang Group and Bashenjiqike Formation had respectively developed during thrust and during quiescence.In a single thrust period,accompanied with thrust loading and lithospheric flexural deformation,lithosphere had transformed from elastic property to viscoelastic,and the basin had widen forward to carton and then had narrowed and deepened forward to thrust-fault belt.Accordingly,the stratigraphic records at the forebulge slope dipping forward to the foredeep were as follows： during early thrust,the strata gradually onlapped and retrograded forward to carton so as to form a great onlap/truncation bottom unconformity;during the late thrust,the strata gradually shrank and prograded forward to thrust-fault belt so as to form a great truncation-toplap top unconformity.During quiescence,the basin was wide and shallow,and the strata appeared parallel and continuous with a few slight truncation unconformities adjacent to thrust-fault belt due to lithosphere rebounding.

关 键 词：库车前陆盆地 早白垩世 岩石圈 弹性 粘弹性 

分 类 号：P534.53[天文地球—古生物学与地层学]