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Water and soil samples were collected along the Hun River to study the concentrations of Cr, Cu and Zn during the dry season, medium season and wet season in 2013. The concentrations of Cr, Cu, and Zn in Hun River were 0.0010 to 0.1298, 0.0057 to 0.1533 and 0.0162 to 0.5004 mg/L, respectively. The concentrations of Cr, Cu, and Zn in soil from around the Dahuofang reservoir were 0.0033 to 0.2149, 0.0054 to 0.2218 and 0.0135 to 0.3544 mg/g, respectively. The results indicated that the concentrations of Cr, Cu and Zn in water from the Hun River and soil from around the Dahuofang reservoir were significantly different at different sample stations and seasons. The pollution indexes of Cr, Cu and Zn in water and soil along the Hun River were calculated using principal component analysis in order to enact future measures against heavy metal pollution. According to the pollution characteristics of heavy metals along the Hun River, a treatment strategy was formulated to provide a scientific basis for the prevention and control of heavy metal pollution along the Hun River. [ABSTRACT FROM AUTHOR]

The Western Liaoning area, where a large number of Jurassic-Cretaceous volcanic rocks are exposed, is one of the typical areas for studying the Mesozoic Paleo-Pacific and Mongolia-Okhotsk subduction process, and lithospheric destruction of North China Craton. The identification and investigation of Early Jurassic adakitic volcanic rocks in the Xintaimen area of Western Liaoning is of particular significance for exploring the volcanic magma source and its composition evolution, tracking the crust-mantle interaction, and revealing the craton destruction and the subduction of oceanic plates. Detailed petrography, zircon U–Pb dating, geochemistry, and zircon Hf isotope studies indicate that the Early Jurassic intermediate-acidic volcanic rocks are mainly composed of trachydacites and a few rhyolites with the formation ages of 178.6–181.9 Ma. Geochemical characteristics show that they have a high content of SiO2, MgO, Al2O3, and total-alkali, typical of the high-K calc-alkaline series. They also show enrichment of light rare earth elements (LREEs) and large ion lithophile elements (LILEs), depletion of heavy rare earth elements (HREEs) and high field strength elements (HFSEs), and have a high content of Sr and low content of Y and Yb, suggesting that they were derived from the partial melting of the lower crust. The εHf(t) values of dated zircons and two-stage model ages (TDM2) vary from −11.6 to −7.4 and from 1692 to 1958 Ma, respectively. During the Early Jurassic, the study area was under long-range tectonic effects with the closure of the Mongolia-Okhotsk Ocean and the subduction of the Paleo-Pacific plate, which caused the basaltic magma to invade the lower crust of the North China Craton. The mantle-derived magma was separated and crystallized while heating the Proterozoic lower crust, and part of the thickened crust melted to form these intermediate-acidic adakitic volcanic rocks. [ABSTRACT FROM AUTHOR]