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塔里木盆地存在前震旦纪结晶基底。已是人们公认之事,但基底固结之前的情况怎样,是模糊不清的。以往的地质文献多数认为是一个完整的古老块体。但自从对物探资料(特别是航空磁测资料)进行深入酌分析研究之后,发现全盆地的背景磁场(见图1)有三种截然不同的特征:南半部为正负条带相间、北东走向的磁场区(异常强度在-100—+200伽马);北半部为变化平缓的负磁场区(异常强度一般在-200伽马);中央西起喀什以
Pre-Sinian crystalline basement exists in the Tarim Basin. It is a well-accepted fact, but what happened before the foundation was consolidated is ambiguous. Most of the past geological literature is considered a complete ancient block. However, since geophysical data (especially aeromagnetic data) have been analyzed in depth, it has been found that there are three distinct characteristics of the background magnetic field in the whole basin (see Figure 1): the southern half is a positive and a negative banding and the northeast (Anomalous intensity of -100- +200 gamma); the northern half of the negative changes in the gentle magnetic field area (anomaly intensity is generally -200 gamma); central west of Kashgar