中文摘要：

川西前陆盆地中-新生代各构造层的残余厚度展布和沉积特征分析发现．四川克拉通周缘的前陆盆地在晚三叠世时期发育于龙门山山前．明显属于龙门山褶皱逆冲构造载荷所形成的前渊凹陷：侏罗纪早期的沉积地层呈面状分布，没有表现出显著的挠曲沉降，指示了一个构造相对平静的阶段；中侏罗世早期前渊凹陷迁移至龙门山北段和米仓山山前，前渊沉积从晚三叠世的北东向转换为近东西向，广泛的湖泊相沉积预示了前陆盆地的欠充填状态：中侏罗世中晚期，川西盆地沉降中心又迁移到大巴山山前．相应的挠曲变形又从近东西向转化为北西向，构成了大巴山的前渊凹陷：晚侏罗世-早白垩世时期，沉降中心再次回到米仓山山前，巨厚的前渊凹陷沉积指示了米仓山冲断带的主要活动时期：白垩纪末-古近纪的前渊凹陷则跃迁至雅安-名山地区。川西前陆盆地的同造山沉降中心以四川盆地中心为核心在西部和北部呈弧形迁移．沉积序列不断更替和叠加。中生界各构造层底界构造图显示现今的构造低部位位于川西北地区和川西南地区．在川西北地区均有东西走向的等值线分布．而川西南地区等值线走向则为北东-南西向。因此分析认为．晚侏罗世至早白垩世的构造变形可能控制了川西盆地现今的地层变形．形成了川西北地区的南北向构造挤压结构．而晚期的新生代构造变形则主要体现在川西盆地的西南部,形成北东-南西向的地层展布特征。

英文摘要：

The authors analyzed the residual thicknesses of various Meso-Cenozoic structural layers and sedimentary characteristics in the western Sichuan foreland basin and found the following： The foreland basin at peripheries of the Sichuan craton occurred in the front of the Longmen Mountains during the Late Triassic, evidently belonging to a foredeep formed under the structural loads of the Longrnen fold-thrust; in the Early Jurassic sedimentary strata were of areal distribution with no markedly flexural subsidence, indicating a tectonically quiet stage. In the early Middle Jurassic, the foredeeps migrated to the front of the Micang Mountains and the northern segment of the Longmen Mountains and the direction of foredeep sediments changed from northeast in the Late Triassic to nearly E-W then. Widespread lacustrine sediments imply a hungry basin. During the middle- late Middle Jurassic, the subsidence center of the western Sichuan basin migrated to the front of the Daba Mountains, with the direction of the corresponding flexural deformation changing from nearly E-W to NW, forming the Daba foredeep. During the Late Jurassic to Early Cretaceous, the subsidence center again returned to the front the Micang Mountain and very thick foredeep sediments indicate the main period of activities of the Micang thrust belt. Then during the Late Cretaceous to Paleogene, the foredeep jumped to the Ya＇an-Mingshan area, southwestern Sichuan. The syn-orogenic subsidence center of the western Sichuan foreland basin migrated in an arcuate form in the western and northern parts with the Sichuan basin as the center, and the sedimentary sequences alternated and were stacked continuously. The contour maps of the bottoms of various Mesozoic structural layers show that the present structure low is located in northwestern and southwestern Sichuan, with E- W-striking contours distributed in northwestern Sichuan and NE-SW-striking contours in southwestern Sichuan. Therefore this paper suggests that Late Jurassic to Early Cretaceous structural d