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利用最新的地球重力场模型 ,计算了新疆及邻近地区的自由空气重力异常、大地水准面扰动异常、地壳和上地幔平均密度异常以及地幔对流引起的岩石层底界面粘滞应力场分布 .根据计算结果 ,对新疆天山地区的构造动力学特征进行了分析和推断 ,认为天山处于地幔对流形成的挤压沉降环境中 ,在南北不对称的挤压应力作用下快速隆升 ,挤压应力场中心在天山以南 .这种应力场特征有利于塔里木板块向天山之下俯冲的观点 .天山南北两侧的准噶尔盆地南缘和塔里木盆地北缘 ,是地壳内质量缺失区 ,是由于南北两侧地壳向天山下挤压而弯曲造成的 .中国天山东段的深部密度分布特征与中段和西段的不同 ,可能是地幔对流分布的东西向差异造成的 .
Based on the latest model of the Earth’s gravity field, the free-air gravity anomaly, the anomaly of the geoid, the average density anomalies of the crust and the upper mantle, and the viscous stress field distribution at the lithosphere bottom boundary due to the mantle convection were calculated. As a result, the tectonic dynamics in Tianshan area, Xinjiang were analyzed and inferred. It is considered that the Tianshan uplifted rapidly under the compressional and subsidence environment formed by the convection of the mantle under the asymmetric compressive stress of the north and south. The center of compressional stress field is South of the Tianshan Mountains.This stress field is conducive to the subduction of the Tarim plate below the Tianshan Mountains.The southern margin of the Junggar Basin and the northern margin of the Tarim Basin on the north and south sides of the Tianshan Mountains are the regions of mass loss in the crust due to the crustal Tianshan under the extrusion and bending caused by the Chinese Tianshan section of the eastern section of the deep density distribution characteristics and the middle and western sections of the difference may be due to the distribution of the mantle convection east-west differences caused.