The genesis of high Ba‐Sr adakitic rocks: Insights from an Early Cretaceous volcanic suite in the central North China Craton

Abstract

The origin of high Ba‐Sr magmatic suites with adakitic features has remained controversial, although they provide important clues on the evolution of continental lithosphere. Here, we present petrological, geochemical, zircon U–Pb and Lu‐Hf data from an Early Cretaceous volcanic suite of andesitic‐dacitic composition in the Laiyuan complex of the central North China Craton, with a view to gain insights on the magma source, petrogenesis, and tectonic implications. The volcanic suite represented by rocks of andesitic‐dacitic composition shows enrichment in light rare earth elements (LREE) and large‐ion lithophile elements (LILE), and depletion in high‐field‐strength elements (HFSE) with no obvious Eu anomalies. They also show typical adakitic features such as high Sr/Y and La/Yb ratios, as well as high Ba‐Sr concentrations. Zircon U–Pb geochronology indicates that these rocks were formed in Early Cretaceous during 131 to 127 Ma, with εHf(t) values ranging from −23.5 to −19.4, suggesting enriched lithospheric mantle source. The geochemical and isotopic data show that the enriched lithospheric mantle source experienced fluid‐related subduction metasomatism. The distinct geochemical features of these identified in our study including high Ba‐Sr concentrations and adakitic affinities were not only inherited from their magma source, but are also a result of fractional crystallization during magma evolution including amphibole‐dominated fractional crystallization at depth and limited plagioclase removal. The volcanism in the Taihang Mountains occurred under extensional regime triggered by the subduction and rollback of the Paleo‐Pacific slab during Late Jurassic to Early Cretaceous and consequent thermal‐mechanical erosion of the lithospheric mantle.

Petrogenesis and tectonic evolution of the Palaeozoic to Mesozoic Niuxinshan granitoids in the North Qilian orogen,NWChina

“…Moreover, they also display weak to moderately negative Eu anomalies (δEu = 0.53-0.62) and linear correlations among elements (e.g., MgO, P 2 O 5 , and Ni) and SiO 2 (Figure 11a-c), indicating fractionation. The isotopic compositions of granitoids are fingerprints for the magma sources (Juteau, Michard, & Albarede, 1986;Xue et al, 2020;Xue, Santosh, Tsunogae, & Yang, 2019). Whole-rock Sr-Nd isotopes of Group I rocks are distinct from those of the adakitic rocks derived from slab or thickened lower crust in the Qilian orogen (Figure 8), which is also shown by lower Sr/Y ratios in contrast with the adakitic affinities (Figure 11d).…”

“…Previous studies proposed multiple models to interpret the generation of the calc-alkaline I-type granitoids, including: (a) the fractional crystallization of mantle-derived basaltic magmas (Jagoutz, 2010;Lee & Bachmann, 2014); (b) reworking of sedimentary materials modified by mantle-like magmas (Collins & Richards, 2008;Kemp et al, 2007); and (c) partial melting of the mafic lower crustal rocks with or without addition of mantle-derived mafic magmas (Chappell & White, 2001;Sisson, Ratajeski, Hankins, & Glazner, 2005;Yang, Santosh, Shaji, & Tsunogae, 2020). At first, Xue, Santosh, Tsunogae, Yang, and Zhou (2020) reported granitoids produced by the differentiation of mantle-derived magmas should be exposed with coeval ultramafic-mafic cumulates in the same region. In Pearce, 1996).…”

Mesozoic magmatic evolution of the Laiyuan complex: Tracing the crust-mantle and lithosphere-asthenosphere interactions in the central North China Craton

“…It should be noted that the formation of a voluminous complex with compositional variations cannot be generated by a single genesis, and it must involve multiple interactions among crust, lithospheric mantle, and/or asthenospheric mantle and various sources involved in the magma's evolution. In this review, based on multidisciplinary investigations carried out by us (Xue et al, 2019b;Xue et al, 2020;Xue et al, 2021) including field studies, petrology, mineral chemistry, whole-rock geochemistry, zircon U-Pb geochronology, zircon Hf isotopes, and geochemical modeling on different rock types from the Laiyuan complex, and previous literature, the objectives of this paper are (1) to clarify the rock types, mineral compositions, paragenetic order, and field relationship between various magmatic suites, (2) to constrain the geochronological framework of magmatism and investigate the geochronological implications on the NCC destruction, (3) to investigate the multiple sources and genesis of various rocks types and establish an integrated petrogenetic model for the Laiyuan complex, (4) to discuss the tectonic setting in the study area during Mesozoic and investigate the lithospheric evolution in the central NCC during Mesozoic.…”

Petrogenesis of the Pandao granites in the Wutai Mountains area in the North China Craton: Constraints from geochemistry, zircon U–Pb geochronology, and Hf isotopes

“…However, the NCC has been partly destroyed since the Mesozoic and Cenozoic (Chen, 2010; Chen, Tian, Jahn, & Chen, 2008; Menziesm, Fan, & Zhang, 1993; Wu, Lin, Wilde, Zhang, & Yang, 2005; Wu, Walker, Ren, Sun, & Zhou, 2003; Wu, Walker, Yang, Yuan, & Yang, 2006; Xu, 2001; Yang et al, 2007; Zheng, Griffin, & O'Reilly, 2007). Researchers have proposed that extensive lithospheric thinning and craton destruction occurred during the Mesozoic and Cenozoic through extensive magmatism (Deng et al, 2004, 2007; Dong et al, 2013; Dong et al, 2018a, 2018b, 2020; Gao, Rudnick, Carlson, McDonough, & Liu, 2002; Gao, Zhang, Xu, & Liu, 2009; Fan et al, 2000; Li et al, 2014a; Lu, Zheng, Li, Chen, & Cheng, 2000; Santosh, 2010; Wang, Fan, Zhang, & Peng, 2006; Wu et al, 2003, 2006; Wu, Xu, Gao, & Zheng, 2008; Xu, 2001; Xu et al, 2008; Xue, 2020; Xue, Santosh, Tsunogae, Yang, & Zhou, 2019, 2020; Yang, 2019; Yang, Santosh, Kim, Zhou, & Xue, 2018; Yang, Santosh, Glorie, Jepson, & Kim, 2020; Zhu, Chen, Wu, & Liu, 2011b). The NCC provides a classic example of craton destruction (Deng et al, 2004; Gao et al, 2002; Lu et al, 2000; Xu, Menzies, Vroon, Mercier, & Lin, 1998; Zhang et al, 2005; Zheng, 1999).…”

“…The blocks finally collided at 1.85 Ga, forming the Trans‐North China Orogen (TNCO; Zhao et al, 2005, 2012). Compared with the EB, where Mesozoic magmatism was frequent (Deng et al, 1999; Hua & Mao, 1999), the research on the TNCO mainly focusses on the Precambrian geological and tectonic evolution, but the Mesozoic magmatism received relatively little attention (Qian, Wei, Zhou, & Zhang, 2013; Qian, Wei, Clarke, & Zhou, 2015; Qian, Wei, & Yin, 2017; Qian, Yin, Zhang, Ma, & Wang, 2018; Qian, Yin, Wei, & Zhang, 2019; Qian & Wei, 2016; Samuel et al, 2020; Santosh, 2010; Tang et al, 2013; Tang, 2017; Wei et al, 2014; Wu et al, 2017; Xiao, Clarke, Liu, & Wu, 2017; Xiao, Clarke, Liu, & Liu, 2019; Xue et al, 2020; Zhang, Wei, Tian, & Zhou, 2013).…”