根据地震纵波速度分析青藏高原地壳放射性生热率和地幔热状态

摘要

A large amount of geophysical data of Tibetan Plateau has been accumulated since 1974 when the modern geophysical exploration about Tibetan Plateau began. P-wave velocities of 23 deep seismic sounding profiles are collected and relationship curve of crustal radiogenic heat and P-wave velocity (A - Vp) in each profile was plotted. The mantle heat flow contour map of Tibetan Plateau is drawn reference to terrestrial heat flow data sets. There is a very high mantle heat flow area on the Bangong-Nujiang suture zone,Indus-Yarlung suture and Lhasa block. It can be infered that the magma under the area is possible active.%从1974年至今,人们对青藏高原的研究积累了大量的地球物理资料.笔者搜集了23条地震剖面纵波数据,利用地震纵波速度和生热率的关系,绘制了各条剖面的地壳岩石生热率随深度变化的等值线,并结合已有的大地热流数据,得到了地幔热流密度分布情况.从地幔热流密度分布可以看出:在班公-怒江缝合带、印度-雅鲁藏布江缝合带、拉萨地体上存在地幔热流较高区域；该区域位于地块碰撞挤压带上,地层构造复杂,地热资源丰富,以著名的羊八井地热田为代表.初步推断该区域地幔岩浆较活跃.