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洋壳的厚度一般为6.5—9千米。地震波传播速度和洋壳厚度的变化反映出海洋基底中存在的巨大构造不均匀性。在我们看来,具有异常厚(超过9—10千米)的地壳的不均匀性最令人感兴趣。因其预计在海洋基底中存在着不均匀性,其中的厚地壳与“花岗岩”层的存在有关,也有一些地壳的变厚是由于典型洋壳的构造“堆聚”造成的。在后一种情况下,海洋基底主要应由变基性岩和辉长岩类型的岩石组成。在地壳均衡改造的范围内,这两种情况下的海底
The thickness of the oceanic shell is generally 6.5-9 km. Seismic wave propagation velocities and oceanic shell thickness variations reflect the large structural heterogeneities present in marine substrates. In our opinion, the heterogeneity of the crust, with unusually thick (more than 9-10 km), is the most interesting. Because of its projected heterogeneity in marine substrates, thick crusts are associated with the presence of “granite” layers and some thickening of the crust is due to “stacking” of typical oceanic crusts. In the latter case, the marine basement should mainly consist of rocks of the metamorphic and gabbro types. In the context of a balanced crustal transformation, the seafloor in both cases