秦岭-大别新元古代-中生代沉积盆地演化

Evolution of Neoproterozoic-Mesozoic Sedimentary Basins in Qinling-Dabie Orogenic Belt

秦岭-大别造山带处于中央造山带的东部,经历了复杂的构造-沉积历史.在系统分析研究区4个二级和13个三级构造单元岩石地层、化石组合、同位素年代学及构造学等资料的基础上,划分出18个沉积盆地类型,并讨论新元古代-中生代构造-沉积演化:(1)新元古代-早古生代:商丹洋以北的北秦岭为岩浆弧和弧前盆地;南秦岭为陆内裂谷-台盆、台地-陆缘裂谷发育阶段;大别-苏鲁为陆内裂谷-台盆台地发育阶段;(2)晚古生代:北秦岭为海陆交互陆表海;勉略洋于泥盆纪开启;南秦岭为弧后陆棚与台盆台地并存发育阶段;(3)三叠纪:陆陆碰撞造山,全区进入前陆盆地发育阶段;(4)侏罗纪-白垩纪:断陷盆地和压陷盆地发育阶段.

As the eastern part of the Central Orogenic Belt,Qinling-Dabie Orogenic Belt has a complicated tectonic-sedimentary history.On the basis of a systematic research on the lithostratigraphy,fossil assemblages,isotopic geochronology and tectonics of 4 secondary and 13 three-level tectonic units,this paper divides the study area into 18 types of sedimentary basins,and dis-cusses its tectonic-sedimentary evolution from Neoproterozoic to Mesozoic：（1）Neoproterozoic-Early Paleozoic：North Qinling was magmatic arc and forearc basin; South Qinling experienced intracontinental rift to interplatform basin-platform to continental-margin rift;Dabie-Sulu experienced intracontinental rift to interplatform basin-platform.（2）Late Paleozoic：North Qinling was marine-continental alternation epeiric sea;Mianl＆#252;e oceanic basin opened in the Devonian;South Qinling was back-arc shelf and interplatform basin-platform at the same time.（3）Triassic：continental collision orogeny,stage of foreland basins. （4）Jurassic-Cretaceous：stage of fault basins and depressional basins.