A TRAVERSE THROUGH THE WESTERN KUNLUN (XINJIANG, CHINA) - TENTATIVE GEODYNAMIC IMPLICATIONS FOR THE PALEOZOIC AND MESOZOIC

The northern part of the western Kunlun (southern margin of the Tarim basin) represents a Sinian rifted margin. To the south of this margin, the Sinian to Paleozoic Proto-Tethys Ocean formed. South-directed sub duction of this ocean, beneath the continental southern Kunlun block d uring the Paleozoic, resulted in the collision between the northern an d southern Kunlun blocks during the Devonian. The northern part of the Paleo-Tethys Ocean, located to the south of the southern Kunlun, was subducted to the north beneath the southern Kunlun during the Late Pal eozoic to Early Mesozoic. This caused the formation of a subduction-ac cretion complex, including a sizeable accretionary wedge to the south of the southern Kunlun. A microcontinent (or oceanic plateau?), which we refer to as ''Uygur terrane,'' collided with the subduction complex during the Late Triassic. Both elements together represent the Kara-K unlun. Final closure of the Paleo-Tethys Ocean took place during the E arly Jurassic when the next southerly located continental block collid ed with the Kara-Kunlun area. From at least the Late Paleozoic to the Early Jurassic, the Tarim basin must be considered a back-arc region. The Kengxiwar lineament, which ''connects'' the Karakorum fault in the west and the Ruoqiang-Xingxingxia/Altyn-Tagh fault zone in the east, shows signs of a polyphase strikes-lip fault along which dextral and s inistral shearing occurred.