Preprints
https://doi.org/10.5194/egusphere-2024-1670
https://doi.org/10.5194/egusphere-2024-1670
10 Jun 2024
 | 10 Jun 2024
Status: this preprint is open for discussion.

Alternating Extensional and Contractional Tectonics in the West Kunlun Mountains during Jurassic: Responses to the Neo-Tethyan Geodynamics along the Eurasian Margin

Hong-Xiang Wu, Han-Lin Chen, Andrew V. Zuza, Yildirim Dilek, Du-Wei Qiu, Qi-Ye Lu, Feng-Qi Zhang, Xiao-Gan Cheng, and Xiu-Bin Lin

Abstract. The Tethyan Orogenic Belt records a long-lived geological cycle involving subduction and collision along the southern margin of the Eurasian continent. The West Kunlun Mountains, located at the junction between the Tibetan and Western Asian Tethyan realm, records multiple orogenic events from the Paleozoic to the Cenozoic that shape the northwestern Tibetan Plateau. However, deciphering the complex Mesozoic contractional and extensional tectonics to interpret the broader Tethyan geodynamics remains challenging. To address the tectonic transition following the early Cimmerian (Late Triassic) collision, this study investigates the newly identified Jurassic sedimentary strata and volcanic rocks in the West Kunlun Mountains. Zircon geochronological results of basalts and sandstones reveal that this ~ 2.5-km-thick package was deposited at ca. 178 Ma, rather than the previously reported Neoproterozoic age. The alkaline basalts at the top of the formation exhibit chemical compositions similar to oceanic island basalts, consistent with the intracontinental extension environment revealed by the upward-fining sedimentary pattern. Provenance analysis, integrating conglomerate clast lithologies with detrital zircons, suggests a substantial contribution from adjacent basement sources, likely influenced by the normal faulting during initial rift stage. These findings indicate that the West Kunlun Mountains rapidly transitioned into an extensional setting after suturing with Cimmerian terranes. The regional structure, stratigraphy and magmatism suggest that this Early - Middle Jurassic basin was subsequently inverted during the Late Jurassic and earliest Cretaceous. We propose that the Mesozoic deformational history in the West Kunlun Mountains was related to the northward subduction of the Neo-Tethys Ocean, as it transitioned from southward retreat to northward flat-slab advancement. Comparing with the entire strike-length of the Eurasian Tethyan orogen, we find that the subduction mode varied from the west to the east, reflecting the broad geodynamic changes to, or initial conditions of, the Neo-Tethyan system.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Hong-Xiang Wu, Han-Lin Chen, Andrew V. Zuza, Yildirim Dilek, Du-Wei Qiu, Qi-Ye Lu, Feng-Qi Zhang, Xiao-Gan Cheng, and Xiu-Bin Lin

Status: open (until 22 Jul 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • CC1: 'Comment on egusphere-2024-1670', Johannes Rembe, 11 Jun 2024 reply
Hong-Xiang Wu, Han-Lin Chen, Andrew V. Zuza, Yildirim Dilek, Du-Wei Qiu, Qi-Ye Lu, Feng-Qi Zhang, Xiao-Gan Cheng, and Xiu-Bin Lin
Hong-Xiang Wu, Han-Lin Chen, Andrew V. Zuza, Yildirim Dilek, Du-Wei Qiu, Qi-Ye Lu, Feng-Qi Zhang, Xiao-Gan Cheng, and Xiu-Bin Lin

Viewed

Total article views: 53 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
41 10 2 53 3 0 0
  • HTML: 41
  • PDF: 10
  • XML: 2
  • Total: 53
  • Supplement: 3
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 10 Jun 2024)
Cumulative views and downloads (calculated since 10 Jun 2024)

Viewed (geographical distribution)

Total article views: 49 (including HTML, PDF, and XML) Thereof 49 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 12 Jun 2024
Download
Short summary
The Tethyan Orogenic Belt documents an extensive history of subduction along the southern margin of Eurasia. This study examines the stratigraphy and provenance of Jurassic strata in the West Kunlun Mountains, highlighting the alternating extensional and contractional tectonic episodes in this region. We interpret that this complex evolution was related to the northward subduction of the Neo-Tethys Ocean, transitioning from southward retreat to northward flat-slab advancement.