【摘要】 为了深入研究大别—苏鲁超高压变质带的深部结构及空间展布特征 ,进一步揭示该超高压变质形成的动力学过程 ,在中国大陆科学钻探场址区进行了广角反射 /折射地震测深调查 .根据广角反射 /折射地震测深的资料研究 ,建立了中国大陆科学钻探场址区的地壳纵波速度结构 .从纵向上来看 ,研究区域的地壳结构可划分为上、中、下 3层 :上地壳的速度小于6 .2 0km/s,厚 10余km ;中地壳的速度为 6 .4 0km/s,厚亦为 10km左右 ;下地壳的速度为 6 .6 0km/s.地壳厚度为 31km左右 ,且其地壳的平均速度为 6 .30km/s.上地壳中的速度倒转指示了超高压变质体在地壳内部的空间分布 ,且超高压变质体在大陆科学钻探场址及其附近的下部呈现为一隆起形态更多还原

【Abstract】 In order to study the deep structure, spatial tectonic characteristics and the dynamic process for the Dabie-Sulu ultral-high metamorphic belt, a wide-angle reflection/refraction seismic survey was conducted in the Chinese Continental Scientific Drilling (CCSD) site. The crustal velocity structure beneath the CCSD site has been established based on wide-angle seismic reflection/refraction data acquired at the site. According to the results, the crust beneath CCSD is composed of three layers: the upper, middle and lower crust, with velocities of <6.20 km/s, 6.40 km/s, and 6.60 km/s, and a thickness of ～10 km, ～10 km, and ～12 km respectively. The crust thickness is 31 km around with an average velocity of 6.30 km/s. However, the reversed velocity in the upper crust implies an ultrahigh-pressure metamorphic (UHPM) layer (body) with a shape of uplift beneath or near the CCSD site.更多还原