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The terranes composing the basement of the Tian Shan were originally sutured together during two collisions in Late Devonian-Early Carboniferous and Late Carboniferous-Early Permian time. Since then, the range has repeatedly been uplifted and structurally reactivated, apparently as a result of the collision of island arcs and continental blocks with the southern margin of Asia far to the south of the range. Evidence for these deformational episodes is recorded in the sedimentary histories of the Junggar and Tarim foreland basins to the north and south of the range and by the cooling and exhumation histories of rocks in the interior of the range. Reconnaissance apatite fission-track cooling ages from the Chinese part of the range cluster in three general time periods, latest Paleozoic, late Mesozoic, and late Cenozoic. Latest Paleozoic cooling is recorded at Aksu (east of Kalpin) on the southern flank of the range, at two areas in the central Tian Shan block along the Dushanzi-Kuqa Highway, and by detrital apatites at Kuqa that retain fission-track ages of their sediment source areas. Available 40 Ar/ 39 Ar cooling ages from the range also cluster within this time interval, with very few younger ages. These cooling ages may record exhumation and deformation caused by the second basement suturing collision between the Tarim-central Tian Shan composite block and the north Tian Shan. Apatite data from three areas record late Mesozoic cooling, at Kuqa on the southern flank of the range and at two areas in the central Tian Shan block. Sedimentary sections in the Junggar and Tarim foreland basins contain major unconformities, thick intervals of alluvial conglomerate, and increased subsidence rates between about 140 and 100 Ma. These data may reflect deformation and uplift induced by collision of the Lhasa block with the southern margin of Asia in latest Jurassic-Early Cretaceous time. Large Jurassic intermontane basins are preserved within the interior of the Tian Shan and in conjunction with the fission-track data suggest that the late Mesozoic Tian Shan was subdivided into a complex of generally east-west-trending, structurally controlled subranges and basins.Apatite data from five areas record major late Cenozoic cooling, at sites in the basin-vergent thrust belts on the northern and southern margins of the range, and along the north Tian Shan fault system in the interior of the range. The thrust belts

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To test existing models for the formation of the Amerasian Basin, detrital zircon suites from 12 samples of Triassic sandstone from the circum‐Arctic region were dated by laser ablation‐inductively coupled plasma‐mass spectrometry (ICP‐MS). The northern Verkhoyansk (NE Russia) has Permo‐Carboniferous (265–320 Ma) and Cambro‐Silurian (410–505 Ma) zircon populations derived via river systems from the active Baikal Mountain region along the southern Siberian craton. Chukotka, Wrangel Island (Russia), and the Lisburne Hills (western Alaska) also have Permo‐Carboniferous (280–330 Ma) and late Precambrian‐Silurian (420–580 Ma) zircons in addition to Permo‐Triassic (235–265 Ma), Devonian (340–390 Ma), and late Precambrian (1000–1300 Ma) zircons. These ages suggest at least partial derivation from the Taimyr, Siberian Trap, and/or east Urals regions of Arctic Russia. The northerly derived Ivishak Formation (Sadlerochit Mountains, Alaska) and Pat Bay Formation (Sverdrup Basin, Canada) are dominated by Cambrian–latest Precambrian (500–600 Ma) and 445–490 Ma zircons. Permo‐Carboniferous and Permo‐Triassic zircons are absent. The Bjorne Formation (Sverdrup Basin), derived from the south, differs from other samples studied with mostly 1130–1240 Ma and older Precambrian zircons in addition to 430–470 Ma zircons. The most popular plate tectonic model for the origin of the Amerasian Basin involves counterclockwise rotation of the Arctic Alaska–Chukotka microplate away from the Canadian Arctic margin. The detrital zircon data suggest that the Chukotka part of the microplate originated closer to the Taimyr and Verkhoyansk, east of the Polar Urals of Russia, and not from the Canadian Arctic.