定量恢复大别造山带侏罗—白垩纪的隆升和剥蚀  

Quantitative method for reconstructing the Dabie orogenic's uplifting and erosion history during the Jurassic-Cretaceous

作　　者：杨欣[1] 李双应[1] 

机构地区：[1]合肥工业大学资源与环境工程学院,安徽合肥230009

出　　处：《地质科学》2011年第2期308-321,共14页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学基金项目(编号:40972082;40572076)资助

摘　　要：以造山带为物源区的周缘盆地中的沉积物记录着物源区的成分特征,保存着造山带的演化历史。根据地层资料,利用质量平衡方法得到大别造山带周缘的合肥盆地、江汉盆地、安庆—潜山盆地和信阳盆地在侏罗—白垩纪的沉积总量为1.685×10~5km^3。大别造山带周缘盆地的平均沉积速率分别为早侏罗世0.407×10~6m^3/a,中晚侏罗世0.921×10~6m^3/a,早白垩世2.107×10~6m^3/a,晚白垩世0.985×10~6m^3/a。并根据造山带剥蚀与盆地充填的动态平衡,将沉积物回剥至造山带,得出大别造山带侏罗—白垩纪总地表剥蚀厚度为4.5 km,各个阶段的平均剥蚀速率分别为11 mm/ka、25 mm/ka、56 mm/ka和26 mm/ka。最终由造山带隆升和剥蚀平衡关系重塑了大别造山带侏罗—白垩纪的隆升剥蚀历史,并与造山带的构造演化格局对比,结论基本一致。The orogenic adjacent basins always record the composition of the source area,and record the evolutionary history of orogenic belts. Based on strata information such as thickness, area and porosity,the paper worked out the sediment accumulation of Hefei Basin,Jianghan Basin, Anqing-Qianshan Basin and Xinyang Basin using the mass balance method. The total deposit of the basins during the Jurassic-Cretaceous is 1. 685×10^5km^3. And the average sedimentation rates of the adjacent basins are ： 0. 407×10^6km^3/a of the Early Jurassic, 0. 921×10^6km^3/a of the Middle and Late Jurassic, 2. 107×10^6km^3/a of the Early Cretaceous,and 0. 985×10^6km^3/a of the Late Cretaceous. Then according to the dynamic balance of orogenic belte＇s erosion and the basin-fill sequences the paper denude back the sediment to the orogenic belt. And figured out the Dabie total thickness of the erosion of the Jurassic-Cretaceous is 4.5 km, furthermore the speeds of average denudation in each phase are 11 mm/ka,25 mm/ka,56 mm/ka,26 mm/ ka. Finally based on the balance between the uplift and erosion the paper reconstruct the Dabie orogenic belt＇s uplifting and erosion history during the Jurassic-Cretaceous, and the result is basically corresponds to the orgenic evolution of the tectonic pattern.

关 键 词：大别造山带 侏罗-白垩纪 质量平衡 侵蚀量 

分 类 号：P512.2[天文地球—地质学]