| Qaidam Basin,located in the northeastern Tibetan Plateau,is an ideal place for studying relationship between Tibetan Plateau uplift,chemical weathering and global climate changes because of its special geographical location as well as thick and successive Cenozoic sediments.However,past studies focus mostly on understanding tectonic deformation of the basin associated with Tibetan uplift and few explore relationship between uplift and chemical weathering.Here we fill this gap and cast light on the relationship between Tibetan uplift,global climatic change and chemical weathering variations in the Qaidam basin based on paleomagnetic dating and chemical weathering index of the Xitieshan section in the northern Qaidam Basin.We highlight the main conclusions as follows:(1)According to the paleomagnetism dating,the Xitieshan section has an age span of 60-2 Ma.(2)The sedimentation rates constrainted by paleomagnetic reversal ages of the Xitieshan section show two high value periods: 20-15 Ma and after ?8 Ma.The results are consistent with periods of intensified tectonic activities in the northern Tibetan plateau.(3)The chemical weathering index records show remarkable similarity to the benthic oxygen isotope record,indicating that global climatic change is the main factor controlling the chemical weathering over the tectonic time-scale in the basin. |
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