Cenozoic tectonic evolution of South China: A brief review, and new insights from the Huangshadong‐Shiba area, south‐east China

Abstract

The Cenozoic tectonic dynamic process controlled by the Pacific subduction and Tethyan subduction/collision in South China are still controversial and lacks geological evidence of intracontinental deformation to define. Here, we focused on the Huangshadong-Shiba area (HSA) in the southeastern coastal area of China. This study aims to obtain multi-stage geological events by an integrated multidisciplinary investigation to decipher the multiple tectonic deformation in Cenozoic South China. We found that the Jurassic and Cretaceous granite not only dominates in surface magmatic rocks but also integrates into a whole with buried depth more than 2 km. This plate-like granite (it means the occurrence of granite is like a tremendous plate) with thickness more than 3 km is sliced by Heyuan Fault, Renzishi Fault, and Zijin-Boluo Fault. The basalts in the Shiba Basin have an Ocean Island Basalt-like property, and the Heyuan Fault controlled the distribution of basalt. Our results, merged with a review of the Cenozoic tectonic evolution in South China, emphasise the decisive role of the India-Eurasia collision on the tectonics of South China in the Palaeogene and suggest the continuous northward drift of the Philippine Sea Plate and Australian Plate had a substantial effect on South China in the Neogene. This study also proposes a two-stage tectonic activity model to visualise the Cenozoic tectonic activity acting on the HSA or South China.

Upwelling of Mantle‐derived Material in Southeast China: Evidence from Noble Gas Isotopes

“…The main feature was extensive intracontinental volcanism, which formed alkaline basalt and basalt extrusive rocks. The intracontinental volcanism and rift are often coupled, and the volcanism is spatially related to extensional faults (Sun et al, 2017), and is considered to have been caused by the ascension of the asthenosphere caused by subduction and a compression upwelling formation (Kuang et al, 2020). In the late Cenozoic, due to the continuous northward drift of the Philippine Sea Plate and the Australian Plate, the tectonic environment in southeastern South China gradually turned into a lefthanded compressive torsional stress state, and the peripheral sea in South China gradually closed or a structural inversion occurred (Suo et al, 2012;.…”

“…Cenozoic basalt veins are distributed near the samples in the Heyuan Basin. The distribution of the basalt is controlled by the Heyuan fault, which was initiated by the upwelling of the asthenosphere material caused by the collision of the India -Eurasia Plate (Kuang et al, 2020).…”

“…He to reduce the R value (Bauer et al, 2016), the samples in the Chaozhou granite area have a high R value and are not affected by the mixing of crust-derived He, showing obvious mantle-derived characteristics. These research areas or on their periphery have developed regional large faults, and at the same time have produced Cenozoic basalts controlled by regional large faults (GBGMR, 1988;Kuang et al, 2020). Combining the gravity wavelet of Guangdong and the surrounding area, the upwelling information of mantle-derived material identified by geophysical surveys such as arrays (Xi et al, 2018;Deng et al, 2019), and from the study of noble gas isotopes in this paper, there is a phenomenon of mantlederived material upwelling in the regional large fault zone where Cenozoic basalt is exposed.…”

“…Previous studies on the magmatism of the Heyuan Basin, the fault system, and the review of the Cenozoic tectonic evolution of South China suggested that the formation of the fault basin in East China (e.g., the Heyuan Basin) and the symbiotic Paleogene basalt were generated by a far-field stress formed by the India-Eurasia collision; subsequently, the continued northward drift of the Philippine Sea Plate in the Neogene terminated basalt eruption and the formation of faulted basins, and caused the reversal of some NE-trending regional faults in Southeast China (Kuang et al, 2020). That is, the upwelling of mantle-derived materials confirmed by He and Ne isotopes might be caused by the still-active Indo-Eurasian Plate collision zone (Yin and Harrison, 2000;Yin, 2010;Hinsbergen et al, 2019 and references therein), the mechanism of which is the collision of the asthenosphere material into the surge (Huang et al, 2015;Yu and Chen, 2016;Wu et al, 2018).…”

“…The Mesozoic magma subsequently formed along the fault emplacement. The occurrence of Cenozoic basaltic magma emplacement in the SE region, such as the basaltic magma emplacement in the Heyuan and Sanshui basins, is also controlled by the lithospheric thinning of the extensional basin (Kuang et al, 2020). The upwelling of these mantle-derived materials has mainly been observed by geophysical methods, such as the magnetotelluric work carried out by Tian (2014) in the Guangdong area that revealed the phenomenon of upwelling channels of multimantle material.…”