Nature and Evolution of Pre‐Neoproterozoic Continental Crust in South China: A Review and Tectonic Implications

Abstract

South China as an amalgamation of the Yangtze and Cathaysia blocks is composed of Archean to Mesoproterozoic basement overlain by Neoproterozoic and younger cover. Both the constituent Yangtze and Cathaysia blocks contain well‐preserved Neoproterozoic rocks that have been extensively studied in terms of the age and tectonic nature, but less is known about their earlier crustal history due to the incomplete rock record. Recent efforts in investigating the yet survived crustal nature based on isotopic and elemental signatures preserved in igneous and sedimentary rocks have steadily improved our knowledge about the pre‐Neoproterozoic continental crustal evolution in South China. In this paper, we summarize the up‐to‐date pre‐Neoproterozoic records, including petrological, geochronological, geochemical and geophysical data, across South China, and discuss its spatiotemporal patterns of the pre‐Neoproterozoic crust and the relevant tectonic events. While the xenocrystic/inherited and detrital zircon records suggest widespread Archean (mainly ca. 2.5 Ga) crustal components within both the Yangtze and Cathaysia blocks, exposed Archean rocks are only limited to isolated crustal provinces in the Yangtze Block. These Archean rocks are dominated by TTGs (tonalite‐trondhjemite‐granodiorite) with varied ages (3.3–2.5 Ga) and zircon Hf isotopes, indicating a compositionally heterogeneous nature of the Archean Yangtze Block and, by inference, the development of multiple ancient terranes. The early Paleoproterozoic (2.4–2.2 Ga) tectonomagmatic events characterize the western Yangtze Block and are supportive of an east‐west subdivision of the Yangtze basement, whereas the late Paleoproterozoic (2.1–1.7 Ga) orogeneses may have affected a larger area covering both the western and eastern parts of the Yangtze Block, and also the Cathaysia Block. The eastern Yangtze Block with generally northeastward‐younging late Paleoproterozoic magmatism and metamorphism likely experienced a prolonged 2.05–1.75 Ga orogenic process welding the various Archean proto‐continents, consistent with the documentation of a buried late Paleoproterozoic orogenic belt imaged by deep seismic profiling from its central part and of a slightly older ophiolitic mélange in the northern part. The Cathaysia Block was probably involved in a short‐lived 1.9–1.8 Ga orogenic event. The two orogeneses overlapped in time and may have contributed to the cratonization of a possible unified South China, and are referred to be linked with the assembly of the Nuna Supercontinent. The subsequent late Paleoproterozoic to early Mesoproterozoic rift successions and intrusions (1.7–1.5 Ga) in the southwestern Yangtze Block, and the ca. 1.43 Ga rifting in Hainan Island of the Cathaysia Block could be responses to the Nuna break‐up. Late Mesoproterozoic (1.2–1.0 Ga) magmatism of varied age and nature in different localities of the Yangtze Block is reflective of a complex tectonic process in the context of the assembly of the Rodinia Supercontinent. Similar‐aged metamorphism (...

Detrital zircon provenance of metasedimentary rocks in the Proterozoic Caiziyuan‐Tongan accretionary complex: Constraints on crustal and tectonic evolution of the Yangtze Block, South China

“…Neoarchean grains account for about 20% of the CTAC detrital zircons and have an age peak at ~2.7 Ga (Figure 8). Widespread 2.8–2.6 Ga detrital, inherited, and xenocrystal zircons indicate that tectonothermal events occurred extensively in the Yangtze Block during the Neoarchean era (Wang et al, 2020; Wang, Dong, Yao, & Zhao, 2020; Xiang et al, 2018; Zheng et al, 2006), representing a significant period for crustal growth and reworking similar to many other major Archean cratons worldwide (Condie et al, 2009). This view has been further supported by a growing number of Neoarchean magmatic rocks that have been recently identified within the Kongling (Chen, Gao, et al, 2013; Gao et al, 2011; Guo et al, 2015), Zhongxiang (Huang et al, 2020; Wang, Deng, et al, 2018; Wang, Li, et al, 2018; Zhou et al, 2015), Yudongzi (Chen et al, 2019; Hui et al, 2017; Zhou et al, 2018), and Phan Si Pan (Zhao et al, 2019) complexes.…”

“…Many studies have revealed that collision‐related magmatism and metamorphism may have been dominant in the Yangtze Block at 2.0–1.8 Ga (e.g., Cui et al, 2020; Cui, Wang, et al, 2021; Han et al, 2019; Huang et al, 2019; Hui et al, 2017; Wang & Dong, 2019; Wang et al, 2015, 2016; Wu et al, 2008; Yin, Lin, Davis, Zhao, et al, 2013; Zhao et al, 2019; Zhou et al, 2017). These observations lead to a consensus that one significant episode of craton‐scale orogeny may have occurred in the Yangtze Block during 2.0–1.8 Ga (Cawood et al, 2018, 2020; Cui, Wang, et al, 2021; Han et al, 2019; Wang & Dong, 2019; Wang, Dong, Yao, & Zhao, 2020), synchronous with the global orogenic events that resulted in the amalgamation of Nuna supercontinent (Zhao et al, 2002) (Figure 8).…”

“…However, Wu et al (2012) proposed that the western and eastern parts of the Yangtze Block may have experienced different evolution history prior to 2.0–1.8 Ga, reinforced by the ~2.15 Ga ophiolitic mélange (Han et al, 2017) and detrital provenance of metapelites (Li et al, 2016; Yin, Lin, Davis, Zhao, et al, 2013) within the Kongling Complex, as well as high‐resolution seismic reflection profiles across this block (Dong et al, 2015; Huang, Zhu, & Xu, 2014). In this regard, some scholars suggest that the initial stabilization of the Yangtze Block at 2.0–1.8 Ga was likely a response to the Nuna assembly (e.g., Cawood et al, 2018, 2020; Han et al, 2019; Wang & Dong, 2019; Wang, Dong, Yao, & Zhao, 2020). Two suites of late Mesoproterozoic ophiolitic mélanges have been recently discovered within the interior of the current Yangtze Block (Miaowan, Peng et al, 2012; Shimian, Hu, Zhai, Wang, Tang, & Ren, 2017), which likely separated this block into the northern and southern sub‐blocks that converged together during the early Neoproterozoic (Li et al, 2021; Lu et al, 2020).…”

“…However, Wu et al (2012) proposed that the western and eastern parts of the Yangtze Block may have experienced different evolution history prior to 2.0-1.8 Ga, reinforced by the ~2.15 Ga ophiolitic mélange (Han et al, 2017) and detrital provenance of metapelites (Li et al, 2016;Yin, Lin, Davis, Zhao, et al, 2013) within the Kongling Complex, as well as high-resolution seismic reflection profiles across this block (Dong et al, 2015;Huang, Zhu, & Xu, 2014). In this regard, some scholars suggest that the initial stabilization of the Yangtze Block at 2.0-1.8 Ga was likely a response to the Nuna assembly (e.g., Cawood et al, 2018Cawood et al, , 2020Han et al, 2019;Wang & Dong, 2019;Wang, Dong, Yao, & Zhao, 2020).…”

Construction of the Continental Asia in Phanerozoic: A Review

“…It is located in eastern Europe, and western, southern, eastern, and southeastern Asia (Figs. 1 and 2), surrounded by the Arabia, India, North China, Tarim, and East Europe cratons, with the South China block, i.e., the Yangtze craton and the Cathaysia block (Wang K et al, 2020), and the Indosinian craton involved in. It is mainly composed of the Alps, Zagros, Hindu Kush, Himalaya, and Qinling-Dabie mountains, and the Iranian, Pamir, and Qinghai-Tibetan plateaus, extending more than 15000 km from east to west.…”