延庆─怀来地区地壳细结构──利用深地震反射剖面

FINE CRUSTAL STRUCTURE IN YANQING─HUAILAI REGION BY DEEP SEISMIC REFLECTION PROFILING

１９９２年底在延庆－怀来地区实施了深地震反射剖面测量，目的是通过对该区地壳细结构的研究来探讨延庆－怀来盆地形成演化的机制和过程，以及与该区地震活动图像的关系．结果表明，研究区上部地壳总体上呈“透明”性质，厚２５－２６ｋｍ；下部地壳具有强烈的反射性质，厚约１４－１５ｋｍ．壳幔过渡带是由双程走时约２ｓ和厚约５－６ｋｍ的水平反射叠层所组成，莫霍界面具有深度深（约３９－４０ｋｍ）和平坦的特点。

At the end of 1992, deep seismic reflection measurements were carried out in Yanqing-Huailai region by Research Center of Exploration Geophysics and Institute of Geophysics of State Seismalogical Bureau.The object of this experiment is to investigate the evolution mechanism and process of Yanqing-Huailai basin and its relation to the seismicity in this region.The results indicate that the upper crust is characterized by seismic transparency with the thickness of about 25-26km and the lower crust is characterized by high reflectivity with the thickness of about 14-15km in this region.The crust-mantle transition zone consists of sets of subhorizontal reflections refferred to seismic lamellae with TWT of 2 seconds and the thickness of about 5- 6km. The Moho is flat and its depth is about 39-40km in this region.