Low‐Temperature Thermochronology for Defining the Tectonic Controls on Heterogeneous Gold Endowment Across the Jiaodong Peninsula, Eastern China

Abstract

This study presents a low-temperature thermochronological data set from the Jiaodong Peninsula in eastern China, including new zircon U-Th/He and apatite fission-track data from the Sulu Terrane in the eastern side of the Jiaodong Peninsula and published data from the Jiaobei Uplift to the west. These data reveal differential tectonic evolution between the Jiaobei Uplift and the Sulu Terrane, which is responsible for their heterogeneous gold endowment. Thermal history inverse modeling and structural analysis indicate three broad periods of cooling in the Sulu Terrane. These include: (a) slow cooling from 114 to 50 Ma; (b) rapid cooling from 50 to 40 Ma; and (c) tectonic stability after 40 Ma with little cooling. This thermotectonic evolution pattern shows that the local tectonic evolution of Sulu Terrane and Jiaobei Uplift are relatively independent, although they share identical far-field geodynamic controls. The critical characteristic is the Early Cretaceous extension within the Sulu Terrane was much weaker than that in the Jiaobei Uplift that underwent a rapid period of uplift in the Aptian. The differential tectonic evolution of the two areas induced variation in structural architecture and consequential differences in degree of extension that are important factors in defining the heterogeneous gold endowment rather than simply suggested differences in ore-forming fluid chemistry, metal precipitation mechanism, and/or exhumation levels. The intense extension in the Jiaobei Uplift was conducive to voluminous fluid migration and gold precipitation. In contrast, the much weaker extensional setting in the Sulu Terrane was not conducive to large-scale fluid migration from deep. Plain Language SummaryThe Izanagi Plate was subducted westward underneath the Eurasian continent beginning in the Jurassic, influencing the tectonic evolution and forming a remarkable metal endowment in eastern China. The Jiaodong gold province in China is composed of the Jiaobei Uplift to the west and Sulu Terrane to the east, hosting gold resources of >5,000 tonnes. More than 85% of the gold resources are hosted in orogenic gold deposits in the Jiaobei Uplift, whereas gold endowment is more limited in the Sulu Terrane. Structural analysis and low-temperature thermochronology from our new study reveal that the tectonic evolution of the Sulu Terrane is different from that previously described for the Jiaobei Uplift. Differential tectonic evolution shows that the local ore-controlling structural evolution of the two areas is relatively independent although both are controlled by the subduction of the Izanagi Plate. This independence reflecting differences in degrees of extension appears to be the major factor responsible for the heterogeneous gold endowment in the Jiaodong gold province. The greater amount of extension in the Jiaobei Uplift relative to that in the Sulu Terrane was more conducive to large-scale fluid migration in the Early Cretaceous, which led to the world-class gold deposit formation.

Hydrothermal Alteration Processes of Xincheng Gold Deposit Jiaodong Peninsula, China: Constraints from Composition of Hydrothermal Rutile

“…The Zhaoyuan-Laizhou and Penglai-Qixia gold metallogenic belts, located within the Jiaobei uplift, account for approximately 85% of the gold resources in Jiaodong [53,54]. The Mouping-Rushan gold belt, situated within the Sulu ultrahigh-pressure terrane, contributes about 15% of the gold resources [55] (Figure 1).…”

“…The 193 nm ArF excimer laser, homogenized through an advanced beam delivery system, was precisely focused on the mineral surface, delivering a fluence of 10-12 J/cm 2 . Measured masses included 23 Na, 24 Mg, 27 Al, 29 Si, 31 P, 39 K, 44 Ca, 49 Ti, 55 Mn, 57 Fe, 7 Li, 9 Be, 11 B, 45 Sc, 51 V, 52 Cr, 59 Co, 60 Ni, 63 Cu, 66 Zn, 71 Ga, 73 Ge, 75 As, 85 Rb, 88 Sr, 89 Y, 91 Zr, 93 Nb, 95 Mo, 111 Cd, 118 Sn, 133 Cs, 137 Ba, 139 La, 140 Ce, 141 Pr, 146 Nd, 147 Sm, 153 Eu, 157 Gd, 159 Tb, 163 Dy, 165 Ho, 166 Er, 169 Tm, 172 Yb, 175 Lu, 178 Hf, 181 Ta, 182 W, 209 Bi, 208 Pb, 232 Th, and 238 U. Each acquisition process began with a 20 s background measurement to establish a baseline (gas blank), followed by a 60 s ablation period where a 30 µm spot diameter was used at a repetition rate of 6 Hz.…”

Genesis and Formation of the Tuwaishan Gold Deposit in Hainan Island, South China: Implications from H-O-S Isotopes

“…Hainan Island is separated from the mainland of South China by the Qiongzhou Strait in the north and is regarded as the southernmost extension of the Cathaysia Block [1,2,24] (Figure 1a). It is tectonically located at the junction of the Eurasian plate, the Indian-Australian plate and the Pacific plate [29][30][31][32][33]. (Revised from [9]).…”

Water Recycling in the Deep Earth: Insights From Integrated μ‐XRF, THz‐TDS Spectroscopy, TG, and DCS of High‐Pressure Granulite

“…120 km, and further experienced rehydration reaction when the subducted crust exhumed to various mantle‐crustal depths (Z. M. Li et al., 2020; Soldner et al., 2020; L. J. Zhang et al., 2018). These high‐pressure mafic granulites are composed of hydrous amphibole and chlorite, anhydrous garnet, and plagioclase with or without clinopyroxene (S. S. Li et al., 2023; Qiu, Deng, Laflamme, et al., 2023; Qiu, Deng, Sai, et al., 2023; H. Y. C. Wang et al., 2016). Most of the peak and early/post‐peak mineral assemblages are preserved in these rocks, whereas some are partly or completely consumed during the retrograde metamorphism (S. S. Li et al., 2023).…”

“…J. Zhang et al, 2018). These high-pressure mafic granulites are composed of hydrous amphibole and chlorite, anhydrous garnet, and plagioclase with or without clinopyroxene (S. S. Li et al, 2023;Qiu, Deng, Laflamme, et al, 2023;Qiu, Deng, Sai, et al, 2023;H. Y. C. Wang et al, 2016).…”