Zircon U-Pb geochronology of the Chinese continental crust: a preliminary analysis of the Elsevier science database

Abstract

The amount of zircon U-Pb geochronological data for China has grown rapidly in recent years. Nearly 410,000 items of zircon U-Pb geochronological data, representing more than 7,000 relevant articles in the Elsevier Science Database, have been collected to a database in this research. Statistics on the ages and absolute errors of these collated data, yielded smallest standard errors for ( 206 Pb/ 238 U), ( 207 Pb/ 235 U), and ( 207 Pb/ 206 Pb) ages within respective time intervals of < 1388.96 Ma, 1388.96-3282.52 Ma, and > 3282.52 Ma. The ages and their absolute errors were determined using three main geochronology methods, based on laser ablation inductively coupled mass spectrometer (LA-ICP -MS), sensitive high-resolution ion microprobe (SHRIMP), and secondary ion mass spectrometer (SIMS) measurements. We compared the influence of these different methods on errors for each age interval. In addition, using a Gaussian model of multi-peak fitting of zircon U-Pb age frequencies, we identified seven growth peaks in zircons from the

A Critical Appraisal of the Sensitivity of Detrital Zircon U–Pb Provenance Data to Constrain Drainage Network Evolution in Southeast Tibet

“… Kernel Density Estimation (KDE) plots for the compiled U–Pb detrital zircon data from different geological domains on the eastern margin of Tibet. The five gray bars indicate the common zircon populations seen in East Asia, associated with the Indosinian orogeny, Caledonian orogeny, Jinning orogeny, Lvliang orogeny, and Wutai orogeny, respectively (Wu et al., 2019). Data used in the compilation are referenced in Supporting Information S2.…”

“…However, as shown in the Jianchuan Basin (see Section 4), Cenozoic volcanic rocks are also widespread in Yunnan Province (Chung et al, 2005), and even in the South China Block (e.g., Nanjing area, Figure 2 for location (Zheng et al, 2013)), suggesting that the Cenozoic zircon grains are also not diagnostic signatures of eastern Tibet. (Wu et al, 2019). Data used in the compilation are referenced in Supporting Information S2.…”

“…From the visual comparison of Kernel density estimation (KDE, Figure 3) using an adaptive bandwidth (same as the other KDE figures) and (nonmetric) multidimensional scaling (MDS, Vermeesch, 2013) plots with bootstrapped confidence regions of the terranes (Figure S2 in Supporting Information S1), we note that in most cases, from Late Triassic time onwards, sedimentary rocks from different terranes in southeast Tibet show similar zircon age populations. The five dominant age groups of 200–300, 400–500, 700–1,100, 1,700–1,900, and 2,400–2,600 Ma are common peaks in East Asia, associated with the Indosinian, Caledonian, Jinning, Lvliang, and Wutai orogenies, respectively (Wu et al., 2019).…”

A global zircon U‒Th‒Pb geochronology database

“…However, this rule of thumb is not always applicable and needs to be improved. Voice et al (2011) 2018) compiled ~420,000 zircon data, including LA-ICP-MS, SHRIMP, SIMS, and TIMS dating methods, using polynomial curve fitting models and obtained recommended ages as follows: 206 Pb/ 238 U age for 0-1.2 Ga, 207 Pb/ 235 U age for 1.2-2.0 Ga, and 207 Pb/ 206 Pb age for > 2.0 Ga. Fang et al (2018) and Wu et al (2019) proposed a new method of recommended age selection that involves analyzing zircon ages and errors from Chinese continental crust collected from the CNKI and Elsevier publishers, respectively. According 245 to the decay principle of the U-Th-Pb isotope system and assuming that the influence of other factors can be ignored, the errors of 206 Pb/ 238 U, 207 Pb/ 235 U, and 208 Pb/ 232 Th ages scale exponentially with age (see Table 3), where factors affecting the coefficients include but are not limited to isotope half-lives and experimental errors.…”

“…However, using zircon 265 production as a proxy involves making certain assumptions, which can be weakened if the dataset used is large enough. Fang et al (2018) and Wu et al (2019) used independent zircon datasets from publishers CNKI and Elsevier to study the Chinese continental crust. The conclusions they obtained are surprisingly similar: some major orogenic movements in the Chinese continental crust agree with the peak periods of zircon production.…”