【摘要】 长320 km横跨鲁西地区的聊城-连云港宽角反射地震剖面揭示了鲁西地区的地壳结构,上地壳为二层结构,总厚18~20 km,速度5.4~6.2 km/s;下地壳也分为二层结构,总厚度13~15 km,速度6.4~6.7 km/s.Moho深度33~35 km.Pn速度为7.9 km/s.地壳速度分布在横向上有较大变化,且平均速度为6.2~6.5 km/s,较正常值偏高.研究结果发现地壳内有两个近直立的高速体.从下地壳延伸到上地壳并直达沉积盆地的底部.可能是幔源岩浆大量侵入地壳,使得地壳的局部平均速度增高.近直立的高速体可能是幔源岩桨上涌的通道.鲁西地壳结构的研究对于探讨古地台的裂解与沉陷机制具有一定的意义.更多还原

【Abstract】 The crustal velocity structure of western Shandong is presented from a DSS profile with a length of 320 km.In this area,the depth of Moho layer is from 33 km to 35 km.The thickness of upper crust is 18～20 km,the velocity is 5.4～6.2 km/s; these of the lower crust are respectively 13～15 km,6.4～6.7 km/s.Pn velocity in this region is 7.9 km/s.Crustal velocity varies transversally at a rather large range.The mean velocity is from 6.2 km/s to 6.5 km/s,higher than the normal value.In the crust there are two nearly vertically high-velocity blocks,stretching from the lower crust to the upper crust reaching the bottom of the sediment basin.It is possible that a large mount of magma from the upper mantle gushes up into the crust,causing the increase of the crustal mean velocity.The high velocity blocks are the channels of mantle magma to go up through.更多还原