Tectonic Evolution of the West Kunlun: Geochronologic and Geochemical Constraints from Kudi Granitoids

Abstract

The West Kunlun contains important information about the early evolutionary history of the Tibetan Plateau. Single-grain zircon U-Pb dating and systematic geochemical analyses were conducted on representative granitic plutons from the Kudi area. The earliest Paleozoic magmatism (471 ± 5 Ma) possesses characteristics of volcanic-arc granites, indicating that Proto-Tethys started to close in the Mid-Ordovician. An arc-continent collision occurred in the Late Ordovician, corresponding to the closure of Proto-Tethys. Following the collision, extensional deformation began in the Early Devonian and gave rise to a post-dynamic, A-type North Kudi Pluton (405 ± 2 Ma) and coeval lamprophyre dikes. Extension was pervasive throughout the whole Kunlun orogenic belt, and was responsible for Devonian to Early Permian magmatic quiescence. The reoccurrence of magmatism in the West Kunlun took place in the Early Permian, when Paleo-Tethys started to be consumed, and a new subduction zone developed in the West Kunlun. Paleo-Tethys closed by the Late Triassic (214 ± 1Ma), and led to rapid uplift and voluminous post-collisional granites.

Geochemistry and geodynamic implications of the Triassic bimodal magmatism from Western Kunlun Orogen, northwest China

“…Numerous studies have been done since the early 1990s (e.g. Jiang et al 1992;Brunel et al 1994;Xu et al 1994;Hsu et al 1995;Matte et al 1996;Ding et al 1996;Pan 1990Pan , 1994Pan , 1996Pan , 2000Mattern et al 1996;Mattern and Schneider 2000;Chen et al 2005;Jiang et al 2002Jiang et al , 2008Xiao et al 2002aXiao et al , b, 2003Xiao et al , 2005Yuan et al 2002Yuan et al , 2005Zhang et al 2006;Li 2007), which have given new insights into the tectonic evolution of this region.…”

Geological characteristics and age of the Dahongliutan Fe-ore deposit in the Western Kunlun orogenic belt, Xinjiang, northwestern China

“…1b). Knowledge of the Tianshuihai geology remains sparse and due to geographic remoteness and widespread glacial coverage (Yuan et al, 2002). As a result, there have been different views on the regional geological evolution.…”

“…For instance, Yuan et al (2002), Zhang et al (2003b), Wang (2008Wang ( , 2011 and Ji et al (2011) have reported ages of 2481 ± 14 Ma (metavolcanic rocks), 2426 ± 12 Ma (gneissic granite), 2210-2270 Ma (hornblende plagiogneiss) and 2130-2700 Ma (schists and gneisses). Therefore, the Paleoproterozoic rocks in either the North Kunlun or the Tianshuihai terranes, or both of them, are likely the detrital sources for the Tianshuihai metasedimentary rocks.Regarding the zircon age population of 2076-1644 Ma (small peaks: ca.…”

“…The South Kunlun terrane consists of a Mesoproterozoic metamorphic complex primarily composed of schist and gneiss locally intercalated with ultramafic lenses (Gaetani et al, 1990;Zhou, 1998), which is lithologically similar to the basement of the North Kunlun terrane (Yuan et al, 2002. The overlying strata are dominated by Upper Paleozoic to Mesozoic siliciclastic-, carbonate-and calc-alkaline volcanic rocks (Pan et al, 1994;Pan, 1996).…”

“…The protoliths to the Precambrian metamorphic rocks had undergone amphibolite facies metamorphism in the Neoproterozoic (ca. 1.0-0.9 and 0.8 Ga) (Matte et al, 1996;Yuan et al, 2002Yuan et al, , 2003Xiao et al, 2003;Zhang et al, 2003aZhang et al, , 2007. The basement is overlain by a low-grade metamorphosed Upper Neoproterozoic (Sinian; ca.…”