龙门山前陆盆地晚三叠世沉积通量与造山带的隆升和剥蚀  

The Sediment Flux of the Longmen Shan Foreland Basin During the Late Triassic Epoch and the Uplift and Denudation of the Orogenic Belt

作　　者：颜照坤[1] 李勇[1] 董顺利[1] 韩冰[1] 陈浩[1] 

机构地区：[1]成都理工大学“油气藏地质及开发工程”国家重点实验室,成都610059

出　　处：《沉积学报》2010年第1期91-101,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(批准号:40972083,49803013,40372084,40841010);中国地质调查局应急项目;中石化前瞻性项目资助的成果

摘　　要：根据钻井资料、地层剖面资料,利用Surfer8.0软件编制出晚三叠世前陆盆地各组段的残留地层等厚图,得出各组段残留地层的沉积总量,并计算出各阶段沉积通量:21.4t/(m2·Ma)、184.2t/(m2·Ma)、278.0t/(m2·Ma)、147.6t/(m2·Ma)、703.5t/(m2·Ma)、272.0t/(m2·Ma)。然后,利用物质平衡法将沉积物回剥至龙门山造山带并进行脱压校正,计算出晚三叠世龙门山造山带剥蚀总厚度为2514m,各阶段造山带剥蚀速率分别为:0.009mm/a、0.114mm/a、0.133mm/a、0.094mm/a、0.423mm/a和0.133mm/a。最终,重塑了龙门山造山带晚三叠世的隆升历史:在距今228.0～199.6Ma的时间内龙门山造山带地壳隆升了约4.3～4.6km,地表隆升了1.8～2.1km;并且隆升过程具有明显的阶段性,可划分为初始隆升(228.0～216.5Ma)、加速隆升(216.5～211.0Ma)、缓慢隆升(211.0～203.6Ma)、急剧隆升(203.6～202.7Ma)和缓慢隆升(202.7～199.6Ma)五个阶段。Based on boreholes and stratigraphic sections,we draw maps about uniformly thick residual formation in the Longmen Shan Foreland Basin with Surfer 8. 0 software,work out the total amount of sediment of residual formation,and figure out the sediment flux in each phase：21. 4t/（ m2·Ma） ,184. 2t/（ m2·Ma） ,278. 0t/（ m2·Ma） ,147. 6t/（ m2·Ma） ,703. 5t/（ m2·Ma） ,and 272. 0t/（ m2·Ma）. Then we denude back the sediment to the orogen-ic belt based on material balance method and carry out depressure correction. We can work out the aggregate thickness denuded is about 2 514 m on Longmen Shan during the late Triassic Epoch,and the speeds of denudation in each phase are：0. 009 mm/a,0. 114 mm/a,0. 133 mm/a,0. 094 mm/a,0. 423 mm/a and 0. 133 mm/a. At last,we reconstruct the history of uplifting during the late Triassic Epoch of the Longmen Shan orogenic belt：the crust in the Longmen Shan orogenic belt uplift about 4. 3 ～ 4. 6 km and the surface of the Longmen Shan orogenic belt uplift about 1. 8 ～ 2. 1 km in the time between 228. 0 Ma and 199. 6 Ma ago,and the process of uplift had the obvious stage features,which could be divided into the initial uplift stage（ 228. 0 ～ 216. 5 Ma） ,the accelerated uplift stage（ 216. 5 ～ 211. 0 Ma） ,the slow uplift stage （ 211. 0 ～ 203. 6 Ma） ,the steeprise uplift stage（ 203. 6 ～ 202. 7 Ma） and the slow uplift stage（ 202. 7 ～ 199. 6 Ma）.

关 键 词：沉积通量 龙门山前陆盆地 剥蚀 龙门山造山带 隆升 

分 类 号：P534.51[天文地球—古生物学与地层学]