Jinlong Dong
Early Devonian mafic igneous rocks in the East Kunlun Orogen, NW China: Implications for the transition from the Proto- to Paleo-Tethys oceans
Dong, Jinlong; Song, Shuguang; Su, Li; Allen, Mark B.; Li, Yanguang; Wang, Chao
Authors
Shuguang Song
Li Su
Professor Mark Allen m.b.allen@durham.ac.uk
Head of Department
Yanguang Li
Chao Wang
Abstract
The tectonic evolution of the Proto- and Paleo-Tethys oceans had a significant influence on ocean-continent distributions in East Asia in the Phanerozoic, and major implications for continental growth in the region. However, it remains ambiguous when and how the Proto-Tethys Ocean transformed into the Paleo-Tethys Ocean. Here we present petrologic, mineralogical, chronological and geochemical data for Early Devonian mafic igneous rocks, located in the East Kunlun Orogen. The mafic igneous rocks include basaltic lavas and diabase dykes, and are tholeiitic in composition. Geochemical and Sr–Nd isotopic data indicate that the basaltic lavas were derived from melting of a spinel-bearing asthenospheric mantle (E-MORB) at normal mantle potential temperatures (1384–1400 °C) with negligible (1–4%) crustal contamination. The diabase dykes probably originated from melting of a spinel-bearing lithospheric mantle metasomatized by subduction-related fluids, with 5–20% crustal contamination, and crystallized at 1100–1135 °C. Both basaltic lavas and diabase dykes have the geochemical characteristics of within-plate basalts. Magmatic zircons from the mafic rocks yield Early Devonian ages (407–403 Ma), postdating the East Kunlun ultrahigh-pressure metamorphism by 19–25 Myr. Comparing our results with the location and timing of the high- and ultrahigh-pressure metamorphic belt, we conclude that the mafic igneous rocks formed in a post-collisional extensional setting. Their generation was associated with both the terminal stages of the Proto-Tethys orogenic belt, (with orogenic collapse promoted by repeated and localized delamination of lithospheric mantle), and early continental rifting related to the evolution of the Paleo-Tethys Ocean to the south. The period of ~426–390 Ma is important for the transition from Proto- to Paleo-Tethys oceans in the East Kunlun Orogen.
Citation
Dong, J., Song, S., Su, L., Allen, M. B., Li, Y., & Wang, C. (2020). Early Devonian mafic igneous rocks in the East Kunlun Orogen, NW China: Implications for the transition from the Proto- to Paleo-Tethys oceans. Lithos, 376-377, Article 105771. https://doi.org/10.1016/j.lithos.2020.105771
Journal Article Type | Article |
---|---|
Acceptance Date | Sep 8, 2020 |
Online Publication Date | Sep 10, 2020 |
Publication Date | 2020-12 |
Deposit Date | Oct 8, 2020 |
Publicly Available Date | Sep 10, 2021 |
Journal | Lithos |
Print ISSN | 0024-4937 |
Publisher | Elsevier |
Peer Reviewed | Peer Reviewed |
Volume | 376-377 |
Article Number | 105771 |
DOI | https://doi.org/10.1016/j.lithos.2020.105771 |
Files
Accepted Journal Article
(1.2 Mb)
PDF
Publisher Licence URL
http://creativecommons.org/licenses/by-nc-nd/4.0/
Copyright Statement
© 2020 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
You might also like
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search