本文根据钻井、地层剖面等资料,利用Surfer8.0软件编制出晚三叠世以来龙门山前陆盆地各构造层序的残留地层等厚图,计算出6个构造层序地层的沉积总量、沉积通量.沉积通量分别为:300.2g/(m2·ka)、66.5g/(m2·ka)、71.7 g/(m2 ·ka)、38.5 g/(m2·ka)、113.0 g/(m2·ka)、1204.6 g/(m2·ka).利用物质平衡法将各阶段沉积物回剥至物源区,计算各阶段物源区剥蚀速率分别为:167.3 mm/ka、22.5 mm/ka、22.9 mm/ka、9.8mm/ka、22.9 mm/ka、319.4 mm/ka.计算结果表明,晚三叠世以来,物源区的剥蚀速率和沉积区的沉积速率均具有先减小后增大的变化规律,晚三叠世和晚新生代是剥蚀一沉积过程最强烈的两个阶段,可能对应了龙门山强烈隆升的两个时期.根据对盆地沉积物总量的估算,利用物质平衡的原理,可以推算出龙门山自晚三叠世开始隆升到现在,龙门山冲断带的地壳隆升幅度大于10 ～ 12km,平均剥蚀厚度超过7.05km.%Based on drillings and stratigraphic sections,writers draw maps about uniformly thick residual formation in the Longrnen foreland basin since the Late Triassic Epoch with Surfer 8.0 software,and figure out the sediment flux in each phase:300.2g/(m2 · ka),66.5 g/(m2 · ka),71.7 g/(m2 · ka),38.5 g/(m2 · ka),113.0 g/(m2-ka),1204.6 g/(m2 · ka).We carry the sediment back to the provenance with the material balance method,and then figure out the speeds of denudation in each phase are:167.3 mm/ka,22.5 mm/ka,22.9 mm/ka,9.8 mm/ka,22.9 mm/ka,319.4 mm/ka.The results show that the speeds of denudation and the sediment flux increased initially and decreased aferwards.The erosion--deposition process was the strongest in the Late Triassic Epoch and the Late-Cenozoic,which may be the two period with strong uplifting in the Longmen Mountain area.Based on estimating the total volume of sediment,with the principle of material balance,we could draw the conclusion that,since Longmen Mountains began to uplifte in Late Triassic Epoch,the Longmen thrust belt uplifted above 10 ～ 12 km,and the aggregate thickness denuded is more than 7.05 km.
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