| Sedimentary basin and orogenic belt are the two basic tectonic units in continent, they constitute the closed contacted tectonic system in space development and formation mechanism. Sedimentary basin documented the most direct and the most specific geological records for the orogenic belt tectonic evolution, it provided the information and clue for the orogenic belt evolution research. The sediments filled in the basin were the result of the orogenic belt rock weathering, denudation, transportation and deposition within drainage area. The sediments not only continuously recorded information of the tectonic evolution of the orogenic belts,but also reflected the climatic and environmental changes during the process of basin formation.Qaidam basin is the closed inland basin of Tibetan Plateau, it lies in the SN extrusion stress of Indian-Eurasian collision. It is surrounded by the Kunlun fault belt(the southern boundary), the Altyn fault belt(the western boundary), the Qilian fault belt(the northern boundary) and contains possibly 6000m (thickest～12,000m)continuous sequence of Cenozoic sedimentary rocks. The huge thickness strata shed from the surrounding mountains, which fully preserved the detailed records of Cenozoic Northern Tibetan Plateau uplift, it is the optimal region to test and perfect the existed mode of Tibetan Plateau uplift. Therefore, understanding the structure and sedimentary evolution process in Qaidam Basin has great significance, which is of importance to the research on the deformation, uplift mechanism of Tibetan Plateau and the long-distance effect after the Indo-Asia collision. Because the lack of absolute age of Cenozoic strata in Qaidam Basin, we couldn't establish the credible strata chronology sequence. The further researches about refined sedimentary-tectonic evolution of Qaidam Basin and the tectonic uplift of Tibetan Plateau has been tied. In order to resolve above scientific problems, the researches of absolute chronology sequence to Cenozoic strata in Qaidam Basin are very imperative and important. We choose the Naoge section in the NE Qaidam Basin as studying object. Through high-resolution magnetostraitigraphy studies, combining with the macroscopical age control of vertebrate fossil, we could establish the detailed chronology sequence of Cenozoic strata. Under the control of strata chronology ,the sedimentary evolution of the Qaidam and the uplift process of surrounding mountains could be revealed through the studies of detailed basin analysis including Cenozoic strata, sedimentary characters(lithology, lithofacies, sedimentary characteristic components, contact relation, et al), space changing rule, paleocurrent direction, sedimentary facies combinations, depositional provenance analysis, deposition rate, sedimentary-tectonic evolution and tectonic rotation. It provides the important information for discussing the formation of basin-mountain physiognomy pattern in the NE Tibetan Plateau .Through our researches in this paper, we mainly obtained the following conclusions:1. Through high-resolution magnetostraitigraphy studies, combining with the macroscopical age control of vertebrate fossil, we establish the detailed chronology sequence of Neogene strata since 17.6Ma. And the widely used stratigraphic units the Xia Youshashan, Shang Youshashan, the Shizigou Formations were formed at >17.6Ma-14.2Ma,14.2Ma-8.3Ma and <8.3Ma, respectively.2.Through the analysis of lithology, sedimentary structure-tectonic, sedimentary geometric morphology, sixteen kind of lithofacies and six sedimentary facies(pluvial fan facies, fan-delta facies, delta facies, fluvial facies, lacustrine and turbidite facies) have been divided in Naoge region of NE Qaidam Basin.3.Through the analysis of sedimentary facies combinations, gravel composition, paleocurrent direction and depositional provenance, we found that paleocurrent direction and depositional provenance underwent three times change in Naoge region at 14.2Ma,11Ma,8.3Ma, respectively. Paleocurrent direction has changed from SW (17.6Ma-14.2Ma) to NE (14.2Ma-11Ma)to SSE(11Ma-8.3Ma) to NW (<8.3Ma).. Depositional provenance have changed from Nan Qilian Shan (17.6Ma-14.2Ma) to Kunlun Shan (14.2Ma-11Ma) to Nan Qilian Shan (11Ma-8.3Ma) to Elashan and Aimunike Shan (<8.3Ma) .4.Through the general analyses including the strata chronology, sedimentary facies combinations, paleocurrent direction, depositional provenance, sedimentary rate, strata contact and basin-mountain coupling relation, NE Qaidam Basin underwent five sedimentary-tectonic evolutional periods and two basin type evolution periods since 17.6Ma. Five sedimentary-tectonic evolutional periods are respectively as 1) the beginning period of Delingha depression (>17.6-16.7 Ma) ; 2) the beginning development period of Delingha depression (16.7-14.2Ma);3) the further development period of Delingha depression (14.2-11.0Ma); 4) the furthest development period of Delingha depression (11.0-8.3Ma);5) gradual shrinkage period of Delingha depression (<8.3Ma) and two basin type evolution periods are respectively as l)the development of foreland basin(>17.6-8.3Ma);2) shrinkage period of foreland basin(<8.3Ma).5.Through the research of paleomagnetic tectonic rotation ,we found NE Qaidam Basin underwent 16.1°±8.6°clockwise tectonic rotation before 8.3 Ma and 16°±7.5°counterclockwise rotation after 8.3 Ma.6. Through the general research including the response relations between tectonic action and sedimentary characters, tectonic rotation et al, there are five intense tectonic uplift events happened in this region since 17.6Ma. They are respectively happened at >17.6Ma,14.2 Ma,11 Ma,9-8.3Ma and <7.6Ma.
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