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The 3D plotting of gold solubility and gold fineness aims to illustrate how to quantify their correlations with ore-forming conditions in hydrothermal gold deposits. The thermodynamic calculation of the Au-Ag solid solutions in Mathematica and the 3D plotting in MATLAB are used to build isopleths of gold solubility and gold fineness at different temperatures (200℃, 400℃), pressures (0.1, 5 kbar), salinities (1, 40 wt% NaCl eq.), and sulfur concentrations (0.01, 0.5 mol/kg). The plot indicates that the ore-forming conditions have different correlations with gold solubility and gold fineness. Average rates of change for the correlations are quantified, showing distinct values in the four pH-logfO2 fields of (I) HSO4−, (II) SO42−, (III) H2S, and (IV) HS−, where dominant gold and silver complexes have different dependencies on the conditions. The quantification of the plots illustrates that a decrease in gold solubility by one order of magnitude is possibly caused by a decrease in temperature of ≥40℃, the salinity of ≥9.6 wt% NaCl eq. or sulfur concentration of ≥0.14 mol/kg, or an increase in pressure of ≥3 kbar, while a decrease in gold fineness by 100 units is possibly caused by a decrease in temperature of ≥14 ℃, pressure of ≥1.4 kbar, or salinity of ≥4 wt% NaCl eq., or an increase in sulfur concentration of ≥0.07 mol/kg. Quantification results suggest that a sharp decrease in temperature may result in large-scale gold mineralization and a great variation in gold fineness. In addition, the quantification reveals that the correlation between gold solubility and gold fineness can be expressed by a function, providing a rapid method for 3D plotting.

Leucogranitic rocks, mainly including leucogranite-pegmatite systems, have been found to be widely distributed in the South Tibetan Himalaya, and they have received considerable interest because of their significance in crustal evolution and associated rare-metal mineralization. Although the nature and geodynamic setting of the Himalayan leucogranites have been well documented by numerous studies, the pegmatites spatially associated with these leucogranites are still poorly understood. Tourmaline is a ubiquitous phase from the leucogranite to the pegmatite. We have therefore conducted in situ major and trace element and boron isotope investigations of tourmaline from the Gyirong pegmatite, synthesizing published data on the Gyirong leucogranite, to document the origin of tourmaline and its genetic implications. Two types of tourmaline (Tur-Ⅰ & Tur-Ⅱ) have been identified in this contribution and they are enriched in Fe, Si and Al but depleted in Mg and Ca, with Mg/(Mg+Fe) ratios ranging from 0.22 to 0.45. Accordingly, the tourmalines belong to the alkali group and have schorl composition. Trace elements, such as Zn, Ga, V, Sc, Li, Sn, Sr, and Co in the tourmalines are relatively enriched, whereas, other trace elements record low concentrations less than 10 ppm. The trace element concentrations of tourmaline are mainly controlled by melt composition. Morphological and geochemical characteristics reflect that the tourmalines from the Gyirong pegmatite are magmatic in origin. The Gyirong pegmatitic tourmalines have S-type granitoids and pegmatites boron isotopic signatures with a tight range of δ11B values between −11.8 and −9.7‰, which is consistent with the magmatic tourmalines (Mg-poor) of the Gyirong leucogranite. This study suggests that the Gyirong pegmatite was the product of crustal anatexis and that the crustal metapelitic rocks within the Greater Himalayan Crystalline Complex were the most likely source components.

Overly rapid urban expansion in the past has significantly changed water resources, resulting in an imbalance between water resources and the sustainable development of new urbanization. To facilitate the sustainable development and utilization of water resources and promote the high-quality development of new urbanization, this study constructs evaluation index systems for water resources and new urbanization. The analytic hierarchy process, entropy method and projection pursuit method are used to determine the weight of each index, and Hebei Province is taken as an example for empirical analysis. The results indicate an upward trend for water resources in Hebei during the 2000–2019 period, while the water resources support capacity and water environmental pollution showed trends of gradual improvement but changed greatly, the water ecological carrying capacity gradually increased, and the negative impact of water disaster damage on the comprehensive situation of regional water resources gradually increased. Meanwhile, a qualitative breakthrough has been made in the development of new urbanization. Based on their evaluation results data, the long-term equilibrium relationship between water resources and new urbanization as well as the dynamics are empirically analyzed using a vector autoregressive model with a variable cointegration test, generalized impulse responses, and a decomposition prediction method using evaluation result data for the 2000–2019 period. There is indeed a supporting and inhibiting dynamic relationship between new urbanization and water resources as well as its components. At the early stage of urbanization, the endowment of water resources, the background value of the water environment, the ecological capacity of water and man-made water disasters were not fully considered, which led to the sharp contradiction between water resources and new urbanization. For a period, the decline in water resource support capacity and serious water environmental pollution have gradually become important factors limiting new urbanization in Hebei, and the constraining effects of the reduced water ecological carrying capacity and water disaster damage have gradually decreased. For future development, decision makers in Hebei should take measures such as adjusting the economic growth mode, improving resource utilization efficiency and technical level, and fully considering the positive role of new urbanization in promoting water resources and water environments. At the same time, Hebei Province should reduce the rate of water resource consumption by strengthening water conservation measures, optimizing the water utilization structure, and increasing investments in water pollution prevention and control to enhance the stability of water environments to realize the coordinated development of water resources and new urbanization.

Groundwater in confined aquifers is the preferred water resource worldwide, and its hydrochemical quality is the premise for sustainable development. A systematic hydrogeochemical research was conducted to get insight into the hydrochemical characteristics, genesis, and potential health threats of confined groundwater, based on analytical data of 45 groundwater samples collected from the urban area of Hengshui, Central North China Plain (NCP). The results showed most groundwater had desirable hydrochemical quality with a nearly neutral to slightly alkaline nature and dominantly soft-fresh Cl-Na face. Solute chemistry was governed by rock-water interaction including minerals dissolution and ion exchange, but out of the anthropogenic influences. All nitrogen pollutants and Zn were within the desirable limit, while F−, Mn, and Fe were beyond the desirable limit recommended by WHO in 28.9%, 15.6%, and 68.9% of samples. Overall chronic health risk from these toxic elements was identified in terms of various populations and mainly contributed by F−. Infants were more prone to the health risks of aqueous pollutants. Differential water supplies based on hydrochemical quality are recommended, and water improvement measures are suggested to be conducted aiming at the harmful fluoride in confined groundwater. The present research could provide valuable references for the health sustainability of confined groundwater utilization in sedimentary plains like NCP worldwide.

Groundwater is an essential resource for sustainable development, whose quality is significant for human health. In the present study, twenty-eight groundwater samples were collected from domestic tube wells and public water supply wells in the Suining area, southwestern China. The integration of statistical analysis, correlations of ions, geomodelling, and entropy-weighted water quality index (EWQI) was carried out to clarify the hydrochemistry and groundwater quality in the study area. By the statistical analysis, the cations followed the concentration order as Ca2+> Na+> Mg2+> K+, while anions’ concentrations were HCO3− > SO42− > Cl− > NO3− > F−. Piper trilinear diagram showed the hydrochemical type was characterized as Ca-HCO3. Correlations of ions and geomodelling revealed the concentrations of major ions were mainly determined by carbonate dissolution and ion exchange process, and NO3− concentrations were controlled by agriculture activities. EWQI computation demonstrated that most of the groundwater samples possessed EWQI values higher than 100. Therefore, groundwater quality is lower than the permissible limit of the World Health Organization (WHO), suitable for drinking purposes in the Suining area. Our study provides vital knowledge for groundwater management in the Suining and other similar areas.

Water scarcity has led to wide use of reclaimed water for irrigation worldwide, which may threaten groundwater quality. To understand the status of groundwater in the reclaimed water irrigation area in Beijing, 87 samples from both shallow and deep aquifers were collected to determine the factors affecting groundwater chemistry and to assess groundwater quality for drinking and irrigation purposes. The results show that groundwater in both shallow and deep aquifers in the study area is weakly alkaline freshwater with hydrogeochemical faces dominated by HCO3-Na·Mg·Ca, HCO3-Mg·Ca·Na, HCO3-Ca·Na, and HCO3-Na. The chemical composition of groundwater in both shallow and deep aquifers is dominantly controlled by the dissolution of halite, gypsum, anhydrite, and silicates weathering, as well as ion exchange. Geogenic processes (rock weathering and ion exchange) are the only mechanisms controlling groundwater chemistry in deep aquifers. Besides geogenic processes, evaporation and anthropogenic activities also affect the chemistry of shallow groundwater. Quality assessment reveals that both shallow and deep groundwater are generally suitable for drinking and irrigation purposes. The quality of deep groundwater is more excellent for drinking than shallow groundwater. However, long-term use of deep groundwater for irrigation exhibits higher potential risks to deteriorate soil property due to the relative higher permeability indexes (PI). Therefore, it is recommended that deep groundwater is preferentially used for drinking and domestic purpose, and shallow groundwater for agricultural irrigation.