新疆天山（独山子）—西昆仑（泉水沟）地学断面地震与重力联合反演地壳构造特征

利用滑动平均的布格重力异常剖面结合地震资料和大地电磁资料,参考介质纵波速度与密度的经验转换关系,通过二维均匀介质模型人机交互式计算得到了新疆天山(独山子)-西昆仑(泉水沟)地学断面走廊域中心剖面的地壳构造特征.所得的反演结果表明,准噶尔盆地与北天山地体、中天山地体为一整体;准噶尔盆地和天山构造带的中、下地壳之间存在低密度层,但塔里木盆地不存在低密度层;由于受到南北两侧板块挤压,造成塔里木盆地的地壳结构在横向上似一南陡北缓、中部隆起的不对称"拱形"弯曲;塔里木盆地南缘与西昆仑构造带间呈"V型盆山耦合关系",其下方恰好是莫霍面上隆区.

Corridor Gravity Fields and Custal Density Structures in Tianshan (Dushanzi)-West Kunlun(Quanshuigou)GGT

Based on the filetered Bouguer gravity anomaly, seismic data and telluric electromagnetic sounding data, the features of crustal structures of the corridor central profile in Tianshan(Dushanzi) West Kunlun(Quanshuigou) GGT are recognized by using modified empirical formula for the relationship between compressional velocity and density as well as the forward formula of uniform media for the two dimensional polygonal model. The inverse results suggest that North Tianshan, Central Tianshan and Junggar Basin are a monolithic body, and that a relatively low density layer exists between the middle and the lower crust in Jungar basin and Tianshan tectonic belt but does not exist in Tarim basin. As the Tarim basin is compressed by plates on both sides, i.e., Kazakstan Plate on the north and Indian Plate on the south, it looks like an asymmetrical arc, being wider in the North, steeper in the south and upwarped in the middle of the Tarim basin. The V shape coupling relationship between the basin and the range is located between the Tarim basin and the West Kunlun tectonic belt, just above the upwarped area of Moho.