Yu Ruilian

Elemental geochemistry and Nd isotopic characteristics of the metasedimentary rocks from the metamorphic belt in central Jiangxi: Provenance and tectonically environmental constraints

The metamorphic belt in central Jiangxi, located in the compound terrain within the Cathaysia, Yangtze Block and Caledonian fold zone of South China, is composed dominantly of meta-argillo-are-naceous rocks, with minor amphibolite. These rocks underwent amphibolite-facies metamorphism. The meta-argillo-arenaceous rocks show large variations in major element composition, but have similar REE patterns and trace element composition, incompatible element and LIE enrichments [high Th/Sc (0.57−3.59), La/Sc (1.46−12.4), La/Yb (5.84−19.0)] and variable Th/U ratios, with ΣREE=129−296µg/g, δEu=0.51−0.86, and (La/Yb)N=3.95−12.9. The Nd isotopic model agestDM of these rocks vary from 1597 to 2124 Ma. Their143Nd/144Nd values are low [ɛNd(0)=−11.4 to −15.8]. Some conclusions have been drawn as follows: (1) The metamorphic rocks in central Jiangxi Province are likely formed in a tectonic environment at the passive continental margin of the Cathaysia massif. (2) The metamorphosed argillo-arenaceous rocks are composed dominantly of upper crustal-source rocks (Al- and K-rich granitic or/and sedimentary rocks of Early Proterozoic), which experienced good sorting, slow deposition and more intense chemical weathering. (3) According to the whole-rock Sm-Nd isochron ages (1113±49 to 1199±26 Ma) of plagioclase-amphibole (schist) and Nd isotopic model agetDM (1597−2124 Ma) of meta-argillo-arenaceous rocks, the metamorphic belt in central Jiangxi Province was formed during the Middle Proterozoic (1100−1600 Ma).The metamorphic belt in central Jiangxi, located in the compound terrain within the Cathaysia, Yangtze Block and Caledonian fold zone of South China, is composed dominantly of meta-argillo-are-naceous rocks, with minor amphibolite. These rocks underwent amphibolite-facies metamorphism. The meta-argillo-arenaceous rocks show large variations in major element composition, but have similar REE patterns and trace element composition, incompatible element and LIE enrichments [high Th/Sc (0.57−3.59), La/Sc (1.46−12.4), La/Yb (5.84−19.0)] and variable Th/U ratios, with ΣREE=129−296µg/g, δEu=0.51−0.86, and (La/Yb)N=3.95−12.9. The Nd isotopic model agest DM of these rocks vary from 1597 to 2124 Ma. Their143Nd/144Nd values are low [ɛNd(0)=−11.4 to −15.8]. Some conclusions have been drawn as follows: (1) The metamorphic rocks in central Jiangxi Province are likely formed in a tectonic environment at the passive continental margin of the Cathaysia massif. (2) The metamorphosed argillo-arenaceous rocks are composed dominantly of upper crustal-source rocks (Al- and K-rich granitic or/and sedimentary rocks of Early Proterozoic), which experienced good sorting, slow deposition and more intense chemical weathering. (3) According to the whole-rock Sm-Nd isochron ages (1113±49 to 1199±26 Ma) of plagioclase-amphibole (schist) and Nd isotopic model aget DM (1597−2124 Ma) of meta-argillo-arenaceous rocks, the metamorphic belt in central Jiangxi Province was formed during the Middle Proterozoic (1100−1600 Ma).

Petrology, chronology and isotope geochemistry of the proterozoic amphibolites from Xiangshan, central Jiangxi province, China

On the basis of a comprehensive study on the petrology, trace elements and isotopic geochemistry of the Xiangshan amphibolites, we suggest that the protoliths of the amphibolites were basalts formed in an island-arc tectonic setting. The basaltic magma was derived from a slightly depleted mantle source with a small amount of crustal contamination. Assemblage of the rock-forming minerals indicates that these amphibolites underwent a low-grade metamorphism of amphibolite facies. According to the formation age (1113 Ma) and subsequent metamorphic age (726.6 Ma) of the basalts as well as the geological and geochemical features of these amphibolites, a tectonic model of Proterozoic oceanic island-arc setting is proposed for central Jiangxi.

Health risk assessment of heavy metals in soil of urban road, Quanzhou City

With the development of urbanization, the environmental quality of urban soil has been declining. Transport has become an important source of heavy metals in soil. To have a preliminary understanding of soil heavy metals pollution in the urban road, in this study, the contents of Cd, As, Pb, Zn, Cu, Ni and Cr in soil of urban road of Quanzhou City were analyzed and investigated to evaluate environmental quality based on health risk assessment model. The results showed that the soil of these urban roads has been polluted by heavy metals. Especially, the pollution of Zn and Cd was the most serious, has exceeded the secondary standard of the environmental quality standard for soils. The order of non-cancer hazard indexes of heavy metals in soil was As > Pb > Cr > Cd > Cu > Ni > Zn, and the order of carcinogen risks of heavy metals was As > Cd. The non-cancer hazard indexes and carcinogen risks of heavy metals were both lower than their threshold values. They were not to be direct threats to people health.

Assessment of toxicity of heavy metal contaminated dustfall in different city zones of QuanZhou by toxicity characteristic leaching procedure

The contents of some heavy metals (Cu, Zn, Pb, Cd and Cr) in dustfall samples from different city zones of Quanzhou were analyzed and their toxicity was assessed by toxicity characteristic leaching procedure (TCLP), which was developed by USEPA. The TCLP method is a currently recognized international method for evaluation of heavy metal pollution in dustfall. The available levels of Cu, Zn, Pb, Cd and Cr were 2.59–63.20, 9.28–3378, 0.15–345.0, 0.08–2.98 and 0.63–9.70 mg·kg−1, respectively, while their international standard were 15, 25, 5, 0.5 and 5 mg·kg−1, respectively. The results showed that the dustfall in different city zones of Quanzhou was polluted by Cu, Zn, Pb, Cd and Cr to some extent, especially by Zn and Pb, followed by Cd, Cu and Cr. The available contents of heavy metals by TCLP method presented different correlations with their total contents, with the correlation coefficients ranging from 0.03 to 0.77.

Evaluation on the Binary Joint Toxicity of Phenol with Substituted Phenols to photobacterium phosphoreum Using Four Evaluating Methods

Binary joint toxicities of phenol with 14 substituted phenols to photo bacterium phosphoreum were determined with the concentration ratio of equal toxic unit (1:1), based on the single toxicity tests of above compounds. Four common-used evaluating methods, toxic unit (TU), additive index (AI), mixture toxicity index (MTI) and similarity parameter (λ), were used to evaluate the types of the binary joint toxicities. And the mechanism of joint toxicity was discussed preliminarily on the basis of the observed data. The results showed that the toxicities of substituted phenols to photobacterium phosphoreum were influenced by the variety, quantity and position of the substituents. Most of the binary mixtures of phenol with substituted phenols presented synergistic effect and others presented addition or antagonistic effect. For the same binary mixture of phenol with substituted phenols, the results of joint action types were incompletely identical using different evaluating methods. TU and MTI were recommended in this work because of their more sensitivity than AI and λ.