| Title | Permian to early Triassic tectono-sedimentary evolution of the Mahu sag, Junggar Basin, western China: sedimentological implications of the transition from rifting to tectonic inversion |
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| Author | Tang, W B; Zhang, Y Y; Pe-Piper, G; Piper, D J W ; Guo, Z; Li, W |
| Source | Marine and Petroleum Geology vol. 123, 104730, 2020 p. 1-15, https://doi.org/10.1016/j.marpetgeo.2020.104730 |
| Image |  |
| Year | 2020 |
| Alt Series | Natural Resources Canada, Contribution Series 20200050 |
| Publisher | Elsevier |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Area | China |
| Lat/Long WENS | 82.0000 87.0000 47.4167 45.0000 |
| Subjects | stratigraphy; sedimentology; tectonics; geophysics; fossil fuels; Science and Technology; Nature and Environment; sedimentary basins; tectonic evolution; rifting; depositional history; subsidence; core
samples; geophysical logging; well logging; geophysical surveys; seismic reflection surveys; isopachs; lithofacies; deltas; fans; alluvial fans; lacustrine deposits; paleogeography; bedrock geology; structural features; grabens; fault zones;
peneplains; sediment dispersal; dispersal patterns; petroleum resources; hydrocarbon potential; hydrocarbons; gas; oil; stratigraphic correlations; Junggar Basin; Mahu Sag; Hong-Che Fault Zone; Ke-Bai Fault Zone; Wu-Xia Fault Zone; Phanerozoic;
Mesozoic; Triassic; Paleozoic; Permian |
| Illustrations | location maps; geoscientific sketch maps; stratigraphic cross-sections; stratigraphic charts; tables; photographs; lithologic sections; seismic profiles; correlation sections; 3-D models |
| Released | 2020 09 29 |
| Abstract | The Permian to early Triassic terrestrial successions in the Mahu sag constrain the tectonic evolution of northwestern edge of the Junggar basin. This study analyzes the sequence stratigraphy of the
Mahu sag in order to understand the interplay between tectonic processes and the sedimentary fill of the basin. It uses detailed analysis of drill cores, geophysical well logs, 2D seismic reflection profiles and isopach maps. Sixteen lithofacies are
grouped into three facies associations: fan delta, fluvial delta and lacustrine. The Permian to Triassic strata are organized into two second-order transgressive-regressive (T-R) sequences, further separated into transgressive systems tracts (TST)
and regressive system tracts (RST). Based on seismic profiles, paleogeographic facies distribution and isopach maps, two stages of tectonic evolution are recognized: 1) early Permian syn-rift to middle Permian post-rift; 2) late Permian to early
Triassic tectonic inversion. During the early Permian, sediments of TST1 record two cycles of depositional system transition from fan delta to deep lacustrine setting within the half-graben structure shown by 2D seismic profiles. At this time,
tectonic mechanical subsidence exceeded sediment supply. The middle Permian post-rift stage (RST2) is characterized by gradual and slow peneplanation, which is documented by sediment supply exceeding thermal subsidence, so that the location of
depocenter shifted and the depositional system transitioned from lacustrine to fan delta setting. Late Permian-early Triassic tectonic inversion is demonstrated by a striking change of the sediment dispersal patterns along the Hong-Che, Ke-Bai and
Wu-Xia fault zones and alluvial fan deposition at the base of TST2. Tectonism is the main factor controlling sediment dispersal, paleogeographic evolution and hence hydrocarbon accumulation, providing a new perspective to oil and gas exploration and
development in the Mahu sag. |
| Summary | (Plain Language Summary, not published)
The Junggar Basin in western China is a major petroleum producing basin with similarities to the Maritimes Basin of Atlantic Canada and Gulf of Saint
Lawrence. This study describes in detail the sedimentation environments and tectonic deformation during the early history of the Junggar Basin and their significance for petroleum geology of the basin. |
| GEOSCAN ID | 326077 |
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