Cooling and uplift history of the Niangniangshan granitic pluton in the Xiaoqinling goldfield, central China: Implications for tectonic evolution and gold mineralization

Abstract

The Xiaoqinling Precambrian metamorphic terrane is located in the southern margin of the North China Craton, where it is the second largest gold‐producing province in China. The Huashan, Wenyu, and Niangniangshan granitic plutons are distributed from west to east across the Xiaoqinling terrane. To fully reveal the terrane's cooling and uplift history, a systematic thermochronological study of the Niangniangshan pluton was carried out in this work. Combined with previous data for the other two plutons, our new data allow us to draw four important conclusions: (a) The Niangniangshan granitic pluton has experienced three cooling–uplift stages, with a rapid stage from 141.7 to 118.5 Ma, a second slow stage from 118.5 to 40.3 Ma, and a final relatively rapid stage from 40.3 to 29.0 Ma. Correspondingly, the cooling rates are 17.24°C/Ma, 0.77°C/Ma, and 11.50°C/Ma. (b) The three plutons experienced similar post‐emplacement rapid cooling stages until ca. 120 Ma, with high cooling rates of about 17–20°C/Ma. Subsequently, their host terrane entered a long period of tectonic quiescence with cooling rates of less than 1°C/Ma. A new diachronous rapid cooling stage began first in the west at 57 Ma, then in the centre at 45 Ma, and finally in the east at 40 Ma with markedly different cooling rates. In this latter rapid stage, the Huashan and Wenyu plutons experienced a much more rapid cooling and uplift than the Niangniangshan pluton, resulting in the higher elevations and larger outcrop area of granitoids in the west and centre of the terrane than in the east. Consequently, the present topography of the Xiaoqinling terrane was close to present‐day form by the Eocene–Oligocene. (c) The emplacement of the three plutons was prior to the regional extension and detachment faulting in the Xiaoqinling terrane, with the evolution of magmatic thermal domes triggering development of the Xiaoqinling metamorphic core complex. (d) Gold mineralization of the Xiaoqinling goldfield took place at ca. 132–125 Ma, which was coeval with the early rapid cooling stage of the plutons and the extensional detachment faulting of the Xiaoqinling metamorphic core complex. Regionally, the gold mineralization overlaps lithospheric thinning and asthenospheric upwelling below the entire eastern part of the North China Craton that occurred during the major extensional regime in the late Early Cretaceous.

EarlyCretaceous‐Cenozoicexhumation history of Luxi Terrane and adjacent areas, eastern North China Craton

“…Kernel density estimate plots from Luxi (a,b), Sulu (c,d), Jiaodong (e–h), TNCO (i–l), and Dabie (m–p). Data collected from X. Cao et al (2015); Chang et al (2019); Clinkscales, Kapp and Wang (2020); Clinkscales, Kapp, Thomson, Wang and Pullen (2021); R. Ding (2006); C. Ding et al (2016); Grimmer et al (2002); S. Hu et al (2005); S. Hu, Kohn, et al (2006); S. Hu, Raza, et al (2006); Z. Huang, Ren and Gao (2016); J. Li, Tang, Liu and Zhang (2010); L. Li, Zhong et al (2012); S. Li, Wang et al (2015); L. Li et al (2018); X. Li and Song (2010); S. Liu et al (2009); Z. Liu et al (2010); J. Liu et al (2013); Qing et al (2008); Ratschbacher, Franz, Enkelmann, Jonckheere and Zhang (2006); Reiners et al (2003); Ren, Zhu, Zhu, Wang and Luo (2015); Su et al (2021); Tang (2010); X. Wang, Zhong, Wang et al (2007); X. Wang, Zhong, Zhang et al (2007); X. Wang et al (2008, 2010); G. Wang, Liu, et al (2013); Y. Wang, Ye et al (2019); P. Wang et al (2022); Q. Wu, Liu, Jonckheere and Wagner (2002a, 2002b); L. Wu et al (2016); L. Wu, Wang, Yang, Wang and Shi (2019); C. Xu et al (2005); L. Xu et al (2016); W. Yang et al (2008); F. Yang et al (2020); Yu et al (2013); J. Zhang, Xu, Wan, Zhang and Gao (2002); F. Zhao (2015); J. Zhao et al (2016); R. Zhao et al (2017); Zhou, Xu, Reiners, Yang and Donelick (2003)…”

Regional Exhumation and Tectonic History of the Shanxi Rift and Taihangshan, North China

“…50–40 Ma (X. Yu, Liu, Zhang, et al., 2013; Y.‐T. Wang et al., 2019), and also with new AFT dates of ca. 47–33 Ma (Figures 5b and 8a).…”

“…The northern Huashan is an ∼ E‐W‐striking footwall block bounded by the Huashan fault to the north (i.e., Taiyao fault; e.g., Y.‐T. Wang et al., 2019) and a S‐dipping fault to the southeast (Figure 3). The Huashan fault juxtaposes Neogene‐Quaternary strata in its hanging wall against Neoarchean‐Paleoproterozoic basement rocks (e.g., X. Yu, Liu, Li, et al., 2013) and ca.…”

“…142 Ma pluton in the eastern Huashan (Y.‐T. Wang et al., 2019) and a K/Ar date of ca. 114 Ma from a ca.…”

Tonian and Cryogenian 40Ar/39Ar hornblende and muscovite ages for the São Gabriel Terrane, Dom Feliciano Belt, southern Brazil

“…As observed in the Precambrian metamorphic terrane of North China, the Niangniangshan granitic pluton experienced high cooling rates (ca. 17-20 C/Ma) after its emplacement and also a long period of tectonic quiescence with low cooling rates (<1 C/Ma; Wang et al, 2019). Terrane is related to a much more complex sequence of tectonic, magmatic, and metamorphic events than previously thought.…”