利用回剥分析重建古构造格局——以川、鄂、湘边区为例

利用回剥分析重建了川、鄂、湘边区二叠系底二叠纪末、中三叠世末、三叠纪末及中侏罗世末的古构造格局，结果表明：二叠纪末古构造形态较复杂，由NE，EW及近SN向3组构造叠加而成， 以NE，EW向构造为主；中三叠世末，其构造格局为两坳一隆一斜坡，以发育近SN向构造为主；三叠纪末，构造面埋深明显增大，主要隆起和坳陷更加醒目；中侏罗世末，总的构造格局为南高北低，构造走向近EW向。黄陵背斜是中生代开始发育的继承性古隆起，而当阳复向斜是与黄陵背斜同期形成的。晚古生代末至中生代，江南隆起开始形成并不断发育。

PALAEOTECTONIC RECONSTRUCTION USING BACKSTRIPPING ANALYSIS —EXAMPLE FROM THE BORDER AREAS OF SICHUAN, HUBEI AND HUNAN PROVINCES

This paper introduces the principle and method of Palaeotectonic Reconstruction Using Backstripping Analysis, and successfully reconstructed the palaeotectonic frameworks of the base of Permian in the border areas of Sichuan, Hubei and Hunan Provinces at the end of the Permian, Middle Triassic, Late Trias-sic, and Middle Jurassic respectively. The result shows: At the end of the Permian, the base of the Permian had a complicated palaeotectonic pattern which consisted of three sets of structures which extended in northeast, east-west and north-south directions respectively. At the end of the Middle Triassic, the general pattern of the tectonic surface consisted of two depressions, one uplift, and one slope. The north-south elongated structures were the main structures developed at the base of the Permian. At the end of the Late Triassic, the palaeotectonic framework formed in the Early-Middle Triassic was largely unchanged , but the buried depth of the tectonic surface increased obviously and the main uplift and depression were clearer. At the end of the Middle Jurassic, the tectonic pattern of the tectonic surface had evidently changed. Its southern part was higher than the northern part and the direction of the main structures was east - west. The Huangling anticline and the Dangyang synclinorium were palaeo-uplift and short to equal axial depression respectively formed during the Mesozoic. The Jiangnan uplift formed at the end of the Palaeozoic and continuously developed during the Mesozoic.