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Granulites and eclogites are useful for revealing the thermal and tectonic evolution of orogens. Early Palaeozoic granulites and associated eclogites in the East Kunlun Orogenic Belt (EKOB) display contrasting metamorphic age. Such asynchronous granulite–eclogite associations have rarely been reported, and the geological significance of their existence remains to be further explored. In this study, petrological and geochronological techniques were used to investigate two felsic and two mafic granulites collected from the Qingshuiquan area in the eastern section of the EKOB. These rocks record similar P–T paths, which are characterized by a peak stage within suprasolidus and high‐pressure (HP) granulite facies conditions (750–832°C and 10.1–12.0 kbar), followed by an initial decompression and cooling stage to subsolidus conditions (600–748°C and 6.5–8.6 kbar), and then a stage of further retrogression under greenschist facies conditions. The protoliths to these granulites are of volcanic and sedimentary origin and suggested to be a component of the continental basement unit. Metamorphic P–T paths indicate that these rocks experienced peak metamorphism at a depth of ~40 km, then cooling and uplift to a depth of ~25 km, and eventually experienced low‐grade retrogression at shallow crustal levels. Cathodoluminescence images and compositional data demonstrate that the zircons in these rocks are of metamorphic origin and they crystallized at or near peak conditions. SIMS U–Pb dating of representative zircon grains yield concordant metamorphic ages of c. 490–520 Ma, with a peak value of 505 Ma on the probability density curve. These ages are similar to other 480–530 Ma ages typically retrieved from EKOB granulites and associated rocks, and are markedly older than the 400–450 Ma ages retrieved from eclogites and their host rocks. The HP granulites and eclogites of the EKOB do not show overprinting relationships. Such asynchronous characteristics imply that the two rock types formed in distinct tectonic settings and at different stages of a protracted subduction–collision process. The studied granulites are suggested to have formed in the root of a continental arc during a stage of Proto‐Tethys Ocean subduction. The formation of the eclogites could be attributed to subsequent deep continental subduction. [ABSTRACT FROM AUTHOR]

It is important to determine the chemical composition of gases trapped in rocks. The technique of using carrier gas and chemical analysis to release and collect gases is very time-consuming. There is little reported about Gas Chromatography analysis of rock degassing under high vacuum, and the total amount of gases are not commonly measured. It is difficult to analyze gases with similar molecular weights by Mass Spectrometer and because of these problems, a high vacuum rock sample degassing device has been developed. The vacuum of the device is < 10-4 Pa. The blank sample pressure is < 0.1 Pa, the accuracy for N2 in the air is 0.63%, and the minimum measurable quantity is < 1 mm3 at standard temperature and pressure. The high vacuum device is coupled with a Gas Chromatography with a pulsed discharge detector, which gives a high sensitive gas chromatographic analysis of the chemical composition of gases in rocks. The gas released from Wudalianchi volcanic rocks in the Songliao Basin reservoirs and shale samples from the Sichuan basin have been analyzed using this system. The results show that the total amount of gas released from the rock can be directly measured. Less sample weight is needed during stage heating, and gas composition analysis is more sensitive compared with the previous experimental device and method. The analyzed main component targeted is the common component in gas-released rock.

U(1)X SSM is the extension of the minimal supersymmetric standard model (MSSM) and its local gauge group is SU(3)C× SU(2)L× U(1)Y× U(1)X. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to MSSM. In the framework of U(1)XSSM, we study the Higgs mass and take the lightest CP-even sneutrino as a cold dark matter candidate. For the lightest CP-even sneutrino, the relic density and the cross section for dark matter scattering off nucleon are both researched. In suitable parameter space of the model, the numerical results satisfy the constraints of the relic density and the cross section with the nucleon. [ABSTRACT FROM AUTHOR]