鲁西隆起晚中生代盆地重矿物组合分析及其构造响应

本文以鲁西隆起区盆地及周边盆地砂岩中碎屑重矿物为研究对象,通过重矿物的稳定性分析,以及通过不同源区重矿物组合的差异,探讨了鲁西隆起及周边地区晚中生代以来的物源及构造演化过程。研究结果显示,鲁西盆地中生代早期早中侏罗纪时期主要源区为鲁西隆起,中晚侏罗纪时期主要物源为胶东地区和鲁西隆起,而早白垩世时期主要物源为胶东地区,其次才是鲁西隆起。晚白垩世沂沭断裂带盆地物源主要是鲁西隆起和胶东地区,鲁西隆起贡献量大于胶东地区。重矿物的稳定性也折射出源区构造演化历史。早-中侏罗世至中-晚侏罗世,鲁西盆地重矿物物源由鲁西隆起向胶东地区的显著转变,暗示着苏鲁造山带自三叠纪形成之后,经折返抬升,至晚侏罗世之前已经到达地表。重矿物的含量变化显示,早白垩世中期和晚白垩世中期鲁西盆地内沉积了大量的鲁西变质岩矿物组合,并且不稳定重矿物含量急剧增加,我们推测鲁西在早白垩世晚期、晚白垩世中期存在两次构造抬升。

Heavy minerals assemblage analysis and its structural indication in Late Mesozoic basin of Luxi uplift

This paper Luxi uplift in the basin and the surrounding sandstone detrital heavy minerals are studied through the stability of heavy minerals,as well as by different source areas between the heavy mineral assemblages are discussed later in Luxi uplift and the surrounding areas since the Mesozoic tectonic evolution and provenance.The results showed that the Early Mesozoic Luxi Early Jurassic period in the main source for the Luxi uplift,in the Late Jurassic period the main source for the Jiaodong and Luxi uplift,while the Mesozoic during the Early Cretaceous main source for the Jiaodong,followed by the Luxi uplift.Late Cretaceous fault basin source Yishu main Luxi uplift and Jiaodong,Luxi uplift contribution is greater than Jiaodong.Stability of heavy minerals also reflects the tectonic evolution history of the source.Early Middle Jurassic to the Late Jurassic,western Shandong Basin heavy mineral material source is to the eastern Shandong Luxi uplift significant change,suggesting the formation of the Sulu orogenic belt from the Triassic period,after he returned to the Late Jurassic uplift before the world had reached the surface.The content of heavy minerals shows that Early Cretaceous and Late Cretaceous sedimentary basins of the mid-western Shandong Luxi metamorphic mineral assemblage of large and unstable heavy mineral content increased dramatically,and we speculated that the late Early Cretaceous in western Shandong,Late Cretaceous mid-existence of two tectonic uplift.