| The major character of neotectonic movement is the periodical uplift in different amplitude in the middle Ordos basin and taphorgeny in different age of the Ordos basin edge. Corresponding to this situation the basin shows the deletion of strata in early Cenozoic (65-10Ma) in the center of the basin and a series of downfaulted basin was formed in the edge of the Ordos basin.The eastern part of the basin has undertaken the sedimentation since 10 Ma;but the whole basin began to have the red clay until 8Ma. Outline of the red clay distribution map is made according to the synthesizing data which include the data got in the field, the petrol and hydrology drilling data, regional and hydrology reporting data, the section data from the collecting information.Thicker red clay in the basin's edge and thinner red clay in the center make the red clay look like an inversed shallow dish. The distribution of the red clay has a close relation to the underlying the relief, which is thicker in the low-lying part and form clear contrast to the high-lying part. The sedimentation of the red clay has no direct relation with tectonic movement but the sediment rate of the red clay has an indirect certain relationship with it.By studying the gravel at the foot of the LiiLiang mountain, conclusion is arrived that can deduce the body of LiiLiang mountain was uplifting between lOMa and 6.7 Ma;Based on fissional tracing, the process of LiuPan mountain's uplift and the terrace of rivers, it can be concluded that the rate of uplift in the eastern part of the basin was greater than the western of the basin before 6.7Ma. LiuPan Mountain's intense uplift began from 5.2Ma;the rate of uplift in the western part of the basin was greater than the eastern part of the basin since 5.2Ma. In other words, there was a tectonic movement invertion in Odors basin at 5.2Ma, which led to the relief invert. The latter, later than the former, may occur 3.5Ma ago. |
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