摘要
本文根据1985—1986年在福建省穿过漳州热田地区完成的一条NNE向地震折射剖面资料,采用一维与二维射线追踪和理论地震图拟合、反演等方法,获得了该地区比较详细的地壳与上地幔顶部结构及速度分布图像.结果表明:漳州热田地区正好位于一个地壳厚度突变带上,从漳州市往南向海岸方向地壳上隆,厚度只有29.5km,往北迅速加大到32.0 km左右;在这个突变带上地壳内所有速度界面均发生扭曲甚至错动,它可能是一个断裂带;地壳中部有一个横向延伸有限的低速区,其最低速度小于5.80km/s,顶部深度大于10.2km,这个低速区正好位于漳州市下方的地壳突变带上.作者推断它很可能就是漳州热田的壳内热源体,并可能是一个部分熔融体.
A seismic refraction profile in the NNE direction passing the Zhangzhou geothermal field in the Fujian Province carred out in 1985-1986. By use of one- and two-dimensions ray tracing, synthetic seismograms fitting and inversion etc., a detailed image of structure and velocity distribution of the crust and uppermost mantle in the region has been obtained.The result shows that: The Zhangzhou geothermal field is just located an area that the crustal thickness changes suddenly there- The crust uplifts in the direction from the Zhangzhou city to the seacoast in the south, and the crustal thickness is only 29.5 km there. But it increases rapidly to about 32.0 km to the north.At the suddenly changed position of the crustal structure, all the seismic velocity interfaces in the crust has been crooked or even broken, this suggests probably a fault belt. There is a P-wave low-velocity zone (LVZ), which is a limited extension laterally, in the middle-upper crust. The velocity of the LVZ is less than 5.80 km/s and it's top depth is more than 10.0 km. The LVZ is just located in the crust beneath the Zhangzhou geothermal field and at the suddenly changed zone of the crust. It suggests that the LVZ is the deep source of the geothermal field and it is probably a portion meltting body.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第1期55-63,共9页
Chinese Journal of Geophysics
关键词
漳州市
地热田
地壳
深部构造
Zhangzhou geothermal field, Crustal structure, Seismic refraction, Lowvelocity zone.
