东秦岭-大别造山带南侧中生代砂岩碎屑组分及其构造意义

利用Dickinson、Suczek等人建立的砂岩碎屑模型,对东秦岭大别造山带南侧中生代盆地碎屑岩的组分特征进行研究,分析碎屑岩的物源区类型,认为中生代砂岩物源主要来自东秦岭大别造山带、龙门山、江南逆冲带,具有明显的再旋回造山带属性,碎屑组分变化序列是盆缘造山带3期逆冲活动的沉积响应。通过分析中生代砂岩碎屑组分的构造意义,探讨了东秦岭大别造山带中生代的构造演化及其盆山耦合关系。

Detrital Composition and their Tectonic Significance of the Mesozoic Sandstones at the Southern Margin of the Eastern Qinling and Dabie Orogenic Belt

Based on the detrital model of sandstone proposed by Dickinson and Suczek et al.,the characters of the detrital composition of the Mesozoic sandstones at the southern margin of the eastern Qinling and Dabie orogenic belt are studied to determine the type of their source areas. it seems that most Mesozoic sandstone were derived from the eastern Qinling and Dabie orogenic belt,from the Longmen mountain and from the Jiangnan thrusting nappe belt, with features of the recycled orogenic belt. The variation sequence of the detrital composition should be the sedimentary response to the three episodes of large scale of thrusting of the orogenic belt surrounding the basins. Through analysis on the tectonic significance of the detrital composition of Mesozoic sandstone,the authors discuss the coupling between basin and mountain and the tectonic evolution during Mesozoic in the eastern Qinling and Dabie orogenic belt.