Jurassic tectonic regime transition of the southwestern Yangtze block, SW China: Evidence from sedimentary provenance analysis
Author Identifier
Yujie Yuan: https://orcid.org/0000-0003-3931-2071
Document Type
Journal Article
Publication Title
Journal of the Geological Society
Volume
182
Issue
1
Publisher
The Geological Society
School
School of Engineering
RAS ID
77397
Funders
National Natural Science Foundation of China (U2202210, 42302162) / Yunnan Fundamental Research Projects (202401AT070435, 202201AU070041)
Abstract
The Lufeng Basin (LFB) in central Yunnan is located on the southwestern margin of the Yangtze Block in the eastern segment of the Tethys tectonic domain, where the Palaeo-Tethys and the Palaeo-Pacific tectonic domains converge. Jurassic red beds in this basin record the closure of the Palaeo-Tethys Ocean and key information on the tectonic transition driven by the spreading of the Palaeo-Pacific plate. We present sedimentary provenance analysis on these Jurassic red beds based on heavy mineral assemblages and detrital zircon geochronology. The results indicate that the strata in this basin were deposited after 214 Ma, and the Early Jurassic Lufeng Fm was mainly sourced from the west of the LFB with minor contributions from western Yunnan. In contrast, the sedimentary provenance of the Middle Jurassic Chuanjie Fm and Laoluocun Formation Fm shifted to the proximal ancient basement surrounding the basin and the east of the LFB. The regional unconformity between the Early and the Middle Jurassic may have resulted from the subduction of the Palaeo-Pacific plate, jointly influenced by two tectonic domains. The sedimentary provenance shift in the Middle Jurassic may be related to the local uplift of the southwestern Yangtze Block caused by the subduction of the Palaeo-Pacific plate. The tectonic regime transition associated with this highest peak of local uplift occurred at c. 170 Ma.
DOI
10.1144/jgs2023-190
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Comments
Wang, J., Luo, L., Yuan, Y., Chu, C., & He, H. (2025). Jurassic tectonic regime transition of the southwestern Yangtze block, SW China: Evidence from sedimentary provenance analysis. Journal of the Geological Society, 182(1). https://doi.org/10.1144/jgs2023-190