| Tectonic deformation and tectonic uplift of Tibet plateau is the hot topic and research front of present international geoscience community. Since～65—45Ma, neotectonic deformation is the main impetus of uplifting of the plateau, the steep slope zone on the circumference is the important geomorphic unit for studying evolution of Tibetan plateau, it is also one of the key areas for inquiring into the uplifting of the Tibetan plateau. Northwestern margin of Tibet plateau is one of the areas which are the highest, the narrowest and nearer away from west syntaxes, it is also the area where the neotectonic deformation is strongest. However, present-day, tectonic deformation of drived uplift of Tibet plateau are poorly constrained.The thesis summarized the spatial-temporal evolution characteristics, deformation sequence, dynamic source and deformation mechanism of neotectonic movement at northwestern margin of Tibetan plateau, then inquired into the time, amplitude and the model of uplifting of the plateau and discussed the formation and evolution process of steep slope zone and genesis of Xiyu conglomerate through the studying of geometrical and kinematical characteristics of large fault system, sedimentation and tectonic deformation of depression basin, late Cenozoic magmatism, the formation and evolution of relief in the steep slope zone and isotopic geochronology in west Kunlun and its north margin at western part of northwestern margin of the Tibetan plateau. There are our main cognitions as follows:Thrusting deformation belt of northwestern in the Tibetan plateau thrusts movement from SSW to NNE for several in late Miocene-eraly Pleistocene. The thrusts of northwestern margin in the Tibetan plateau show backward propagating mode, while the fold-thrust belts of margin in the basin show forward propagating mode. The deformation's amplitudes of fold-thrust belt in depression basin decrease from orogene to basin, most are fault-propagation fold related to buried thrust and form growth fold or growth strata. The most important deformation has taken place in the sedimentary period in middle Pliocene to early Pleistocene (～3.6-1.1Ma), regional fold deformation also occur in this period, and forming regional angular unconformity.Filled sequence of the sedimentary basin can reflect tectonic evolution of the basin dominate sedimentation under regional tectonic setting.Kashi group in depression basin of the southwest tarim is sediments of shallow sea to lagoon facies, Wuqia group is sediments of delta to plain fluvial facies, Atushi formation is sediments of fluvial to fan margin facies, while Xiyu conglomerate is upper fan to middle fan alluvial-diluvial deposition. Kashi group is shallow sea facies sediments in stable tectonic setting; Wuqia group is fine grained clastic sediments in relative tectonic quiescent; from Atushi formation fine conglomerate begins to appear, and its component maturity begins to lower, which imply that source area is much nearer and the landform contrast is sharper, Pakabulake formation is parallel unconformable contact with Atushi formation above in the margin of basin, which display that neotectonic movement reinforced and regional uplifting have occurred there; Xiyu conglomerate is almost coarse conglomerate and its component maturity is low, containing massive debris-flow deposit, paleocurrent varies sharply from SE and SEE in the sedimentary period of Wuqia group to NW and NNW in the sedimentary period of Atushi formation, which imply that the landform contrast has further increased, sedimentary rate increase rapidly, fault on the mountain front has activate intensely and the Kunlun mountains fast raised.Magmatic activity is associate matter of tectonic monement. Magmatic activity at northwestern margin of Tibet plateau is rare before Miocene, Magmatic activity begin to increase form10-8Ma. We found three late Miocene small stocks at north Quanshuigou, their zircon SHRIMP U-Pb ages are respectively 10.1±0.4 Ma, 9.7±0.2Ma ,9.1±0.3 Ma, while these ages are agreement of age of east Kunlun strike-slip fault by strike-slip rates estimating.Geochemical character indicates EM II granites, and intruded in pull-apart area of strike-slip fault.Moreover, we found Qitaidaban late Miocene trachyte volcanic at north Tianshuihai, the whole rock 40Ar-39Ar age is 8.3±0.3 Ma. Volcanic activity significantly enhanced since 10-8Ma, geochemical analysis is revealed that their origin is admixture of mantle and crust, spatial distribution of magma are contral of pull-apart basin of strike-slip fault, they are result of India-Asia collision functionary of matle and crust.The AFT ages record the cooling and denudation history of rock in the uppermost crust about 3km, and AFT modeling is a effective means what understand rocks erosion's history.We acquired the AFT age of 24.8～14.0Ma by analyzing the AFT of granite on the surface of plateau in north Quanshuigou, which show that this granite undergo two rapid cooling periods which are 25～17Ma and 5～2Ma through thermal history simulation. The age concentrated in 5～2 Ma by analyzing the AFT of granite in Xinjiang-Tibetan highway from Kudi to Mazha, reflecting rapid cooling since Pliocene. By analyzing the AFT of granite of Yuetangnengdailiya in steep slope zone of west Kunlun Mountains, show that the age is very new and their main interval is 2.9±0.5～0.9±0.3Ma, different rocks have the characteristic of the upper the younger, the lower the older, presenting backward propagation thrust nappe structure; also reflecting rapid cooling since middle Pliocene.Geomorphic of Tibetan Plateau is controlled of tectonic deformation.The development of drainage system is obviously controlled and affected by neotectonics. Drainage system in west Kunlun mountains and its margin can fall into two classes: longitudinal drainage to the south of main peak of West Kunlun mountains, and transverse drainage to the north according to the relationship between drainage and tectonic. Longitudinal drainage generally extend in EW direction approximately, the rivers are long, the valley is wide and the gradient is small, is a ancient geomorphic unity and the age is not later than 3.82Ma. Transverse drainage generally extend in SN direction approximately, the rivers are short and the gradient is large, upper part of the valley is wide while the lower is narrow, it generally develops 4-6 terraces, indicating it's a young geomorphic unity which formed after 1.1±0.1 Ma, showing intense neotectonic movement.Synthesize the research of tectonic deformation , such as a series of fold systems and regional large fault zone, integrating with sedimentation, regional magmatic activity, the AFT age, and evolution of drainage landform, we bring forth that: tectonic upliftt at northwestern margin of Tibet plateau is a multistage,complex uplifting process that is a agreement of tectonic deformation, underwent initial uplift at 25-17Ma, eraly little uplift of at 10-8Ma, middle speed uplift at～5.3—3.6Ma, late aggravated uplift at～3.6—0.7Ma, and slower uplift since0.7Ma, then the plateau uplift intensely, reaching its highest altitude and was brought into the cryosphere.The most important uplift took place at middle Pliocene-middle early Pleistocene (～3.6-0.7Ma), main uplift form is thrust movement by from boundary thrust for peripheral basin, ground uplift amount is about 2000～3000m in northwestern margin of Tibetan plateau since middle Pliocene-middle early PleistoceneAuthor think that neotectonic dynamic source at northwestern margin of Tibetan plateau comes from the NNE direction compression of Indian plate and the SSE direction hold up of Tarim basin and is associated with the northward wedging effect of west Pamir syntaxis through the analysis of tectonic trace ,modern tectonic stress field and present-day GPS data, imply that it is related of west structural knot. Besides, it indicated stronger wedge in early Pliocene and middle-late Pleistocene.
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