【作者】 朱连； 李平一；

【Author】 Zhu Lian Li Pingyi (Institute of Geophysics,Chinese Academy of Sciences)

【机构】 中国科学院地球物理研究所；

【摘要】 分析了准噶尔盆地(44°0′-46°15′,84°37′-87°47′)的航磁数据,得到小于0.05 cyc/km的低频径向功率谱.利用Spector和Grant(1970)的模型,同时计算单层磁集合体的平均顶深、厚度、水平尺度及磁化强度的最佳值,求得磁性地壳的上界面和下界面深度分别为7和43km.7km的深度与盆地中地震剖面的古生界顶面相符,43km与重力算得的莫霍面深度相符,盆地的地壳地温梯度推测为不大于14℃/km,而油井中的地温梯度值为1.87℃/100m.更多还原

【Abstract】 Aeromagnetic data of the Junggar basin are analyzed to yield radial power spectrum of low frequencies(<0.05cyc/km).Parameters in the Spector and Grant model(1970),viz.average depth,thickness,lateral extent and magnetization,are estimated simultaneously by matching the observational spectrum with the spectra of a succession of models with 4 varying parameters. The optimum depths to top and to bottom,7km and 43km respectively,are interpreted as the upper and lower boundary of the magnetic crust in the area.The lower boundary is in agreement with the Moho derived from gravity data.The crust geothermal gradient is inferred to be less than 14℃/km in contrast to the value of 1.87℃/100m in the oil wells.更多还原