|Title||Permian rifting processes in the NW Junggar Basin, China: implications for the post-accretionary successor basins|
|Author||Tang, W; Zhang, Y; Pe-Piper, G; Piper, D J W; Guo, Z; Li, W|
|Source||Gondwana Research vol. 98, 2021 p. 107-124, https://doi.org/10.1016/j.gr.2021.06.005|
|Alt Series||Natural Resources Canada, Contribution Series 20200004|
|Media||paper; on-line; digital|
|File format||pdf; html|
|Lat/Long WENS|| 82.0000 87.0000 47.3333 44.6667|
|Subjects||tectonics; structural geology; stratigraphy; geophysics; sedimentology; geochronology; Nature and Environment; Science and Technology; basin evolution; tectonic evolution; rifting; subsidence; faulting;
volcanism; plate margins; geodynamics; depositional history; sedimentation; sediment dispersal; provenance; thermal history; bedrock geology; structural features; faults, strike-slip; fault zones; grabens; lithology; sedimentary rocks; volcanic
detrius; geophysical surveys; seismic reflection surveys; seismic refraction surveys; sedimentary petrology; radiometric dating; uranium lead dating; zircon dates; crustal thickness; crustal structure; Junggar Basin; Central Asian Orogenic Belt;
Irtysh Fault Zone; North Tianshan Fault Zone; Phanerozoic; Mesozoic; Cretaceous; Paleozoic; Permian|
|Illustrations||geoscientific sketch maps; schematic cross-sections; geochronological charts; stratigraphic charts; seismic profiles; photomicrographs; plots|
|Released||2021 06 09|
|Abstract||The Junggar Basin, bounded by the West Junggar along late Carboniferous strike-slip faults in the west, is a post- orogenic successor basin within the Neoproterozoic to Paleozoic Central Asian Orogenic
Belt (CAOB). The Junggar Basin is a key region for understanding the Permian rifting processes since it is located in an extensional step-over zone between the Irtysh and North Tianshan strike-slip fault zones that were most active in the Permian.
Based on new seismic reflection profiles, detrital petrology and zircon U-Pb ages, together with regional geological data and a refraction seismic profile, this study investigates the tectonic evolution and the geodynamic mechanics of the basin. The
early Permian phase of syn-rift mechanical subsidence in the western Junggar Basin formed half grabens. Volcanic detritus is abundant, and detrital zircon U-Pb ages show sediment supply was entirely local. During the middle Permian post-rift phase
with thermal subsidence, sediment supply exceeded subsidence, and there are increasingly distant sources of sediment. The Permian regional extensional stress field between major post- accretionary strike-slip fault zones triggered the reactivation of
the pre-existing late Carboniferous strike-slip faults in West Junggar and produced thinning of the crust beneath the Junggar Basin, with a ß crustal stretching factor of 1.74. Seismic refraction data reveals asthenospheric upwelling resulted in
underplated mafic lower crust (6-10 km). The location of initial rift axis in the Junggar Basin was controlled by the juxtaposition of thin and weak crust beneath the basin and relatively strengthened thick crust in the West Junggar attributed to the
cooling of A-type granites, resulting from localized strain. Similar location of post-orogenic rifting in southwestern CAOB, in areas of high heat flow following collision, suggests that Junggar Basin is an example of a more general process.
|Summary||(Plain Language Summary, not published)|
The Junggar Basin in western China is a petroleum-rich basin that has a remarkably similar history to the Magdalen Basin in the Gulf of St Lawrence. This
study uses a variety of geological techniques to determine how prior geological history determined the location and early evolution of the Junggar Basin.