【摘要】 <正> 柴达木地体大致为现在的柴达木盆地范围.大地构造上,它是一个微型大陆或中间地块.目前,柴达木地体内已知出露最老的地层为前震旦系达肯大坂群.不整合于达肯达坂群之上的是震旦系的全吉群和下寒武统含冰碛岩的小高炉群.1985年,我们对全吉群进行了古地磁研究,其目的:①求得柴达木地体震旦纪的古纬度;②初步了解全吉群的磁性地层特征,并与我国其他地区同时代地层进行磁性地层相对比.更多还原

【Abstract】 Paleomagnetic data from the Quanji Group of Late Precambrian ( Sinian ) age have been obtained from the Chaidam terrane. Directions of magnetization from six sites spanning 600 m.y. to 700 m.y. give a mean direction of Dec. = 115.3°, Inc.=0.8, K=6.1, α95=29.6° after tilt correction. Both magnetic polarities are present The equatorial latitude of the Quanji Group is consistant with that of the Tarim craton during the Sinian, Suggesting that the Chaidam terrane probaly had an affinity with the Tarim craton. Since the Quanji Group is stratigraphi-cally below the lower Cambrian tillite of the Xiaogaolu Group, the paleomagne-tic data imply that the Xiaogaolu Group tillite also formed in low latitudes.更多还原