Geological significance of new zircon U-Pb geochronology and geochemistry: Niuxinshan intrusive complex, northern North China Craton.

The Huajian gold deposit is one of the largest hydrothermal intrusion-related gold deposits in eastern Hebei Province, located in the northern margin of the North China Craton (NCC). The mineralization in this district displays a close spatial association with the shoshonitic Niuxinshan intrusive complex (NIC), which contributes to the characterization of the metallogeny associated with convergent margin magmatism. In the current study, new geochronological and geochemical data are combined with previously published isotopic data, obtained from the granitic rocks in the NIC, to constrain the timing of the district's tectonic setting transformation and determine its bearing on regional metallogeny.

[Raman spectroscopic study of the complex and quantitative analysis in the system CuCl2-H2O and FeCl3-H2O].

In the present paper, the Raman peaks of complex in the CuCl2-H2O system and FeCl3-H2O system were studied in detail. In the CuCl2-H2O system, the superimposed characteristic peaks of various complex formed by Cu2+ and Cl- (such as [CuCl4]2- and [CuCl6]4-) may be formed the peak of 286 cm(-1), and the superimposed characteristic peaks of various complex formed by Cu2+ hydrate([Cu(H2O)4]2+ and [Cu(H2O)6]2+ based) may be formed the peak of 412 cm(-1); Through the analysis of peak parameters, we has founded two quantitative relationships: (1) The peak intensity ratio (I1 I3I 400 or I2/I3 400) of 286 cm(-1) (or 412 cm(-1)) and OH stretching Raman spectrum of water (at 3 400 cm(-1)) and concentration; (2) The integral area of 286 cm(-1) (or 412 cm(-1)) and concentration. In the FeCl3-H2O system, 173 and 331 cm(-1) might be attributed to [FeCl4]- that is the most common form of FeCl3 complex in aqueous solution.

[Effects of cations in chlorine salt solution on O-H stretching Raman spectra of water].

In order to understand the effects of the common cations in geofluids on the structure of water, the present paper systematically studied the Raman spectra of NaCl-H2O, CaCl2-H2O, MgCl2-H2O, CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O solutions by two methods. (1) The frequency shifts of the peak maximum around 3,400 cm(-1) in O-H stretching Raman spectra of water reveal the destruction effects of these cations on the structure of water: Ca2+ > Mg2+ > Na+, Fe3+ > Zn2+ > Cu2+; (2) Comparing the intensities of the shoulder peak around 3,250 cm(-1) in the O-H stretching Raman spectra of water: (1) all salts concerned destruct the structure of water; (2) with respect to the same chloride, the destruction extent of hydrogen-bond increases with concentration increasing; (3) comparing different chloride solutions at the same concentration, the destruction effects of catnions on the structure of water decrease in the sequences Ca2+ > Mg2+ > Na+ and Fe3+ > Zn2+ > Cu2+. (4) A hydrogen bond-affected mechanism combining cation destruction with complex compound production is supposed for the first time, and is used to explain the effects of the canions on the structure of water: CaCl2 > MgCl2 > FeCl3 > NaCl > ZnCl2 > CuCl2.