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51.
《China Geology》2018,1(1):72-83
With the technological development of exploitation and separation, the primary sources of lithium have gradually changed from ore to brine, which has become the main raw material, accounting for more than 80% of the total production. Resources of lithium-bearing brine are abundant in China. This paper has summarized the spatial and temporal distribution, characteristics, and formation mechanism of the lithium-rich brine in China, aiming to provide a comprehensive set of guidelines for future lithium exploitation from brines. Lithium-rich brines usually exist in modern saline lakes and deep underground sedimentary rocks as subsurface brines. The metallogenic epoch of China’s lithium-rich brine spans from the Triassic to the Quaternary, and these brines exhibit obvious regional distribution characteristics. Modern lithium-rich saline lakes are predominately located in the Qinghai-Tibet Plateau. In comparison, the subsurface lithium-rich brines are mainly distributed in the sedimentary basins of Sichuan, Hubei, Jiangxi provinces and so on in south Block of China, and some are in the western part of the Qaidam Basin in Qinghai province in northwestern China. Lithium-rich saline lakes are belonging to chloride-enriched, sulfate-enriched, and carbonate-enriched, while the deep lithium-rich brines are mainly chloride-enriched in classification. On the whole, the value of Mg/Li in deep brine is generally lower than that of brine in saline lakes. The genesis of lithium-rich brines in China is not uniform, generally there are two processes, which are respectively suitable for salt lakes and deep brine.  相似文献   
52.
Based on the geological and hydrogeological conditions along with dynamic changes of groundwater level, this paper analyzes the hydrodynamic characteristics of saltwater intrusion in the study area. According to monitoring data of groundwater quality, the distribution characteristics of macro component are analyzed, and then fuzzy comprehensive evaluation method is adopted to evaluate the impact of saltwater intrusion on groundwater environment. Concerning the influence degree of groundwater environment, the study area is divided into brine area, seriously influenced area, moderately influenced zone, slightly influenced zone and uninfluenced zone. The results can offer references for prevention and control of saltwater intrusion as well as the protection of water resources.  相似文献   
53.
This work identifies and describes features of the changing seasonal frost-covered surface of Mars based on HiRISE images, and analyses the possibility that ephemeral liquid brine formation produces them. Because some of these dark features show flow-like appearance, and salts on Mars are present, liquid brines might be also present, possibly accounting for the changing droplet-like features on the Phoenix lander.We observed in-situ darkening and movement of dark features (or movement of the darkening front) on seasonal frost-covered polar dunes. Darkening and brightening may happen within several meters from each other during local spring. Darkening always starts from the bottom and moves up, while brightening progresses from top and moves toward the bottom between the small dune ripples. Brightening occurs during the springtime warming on time scales of several days close to the sites of darkening; therefore, dark material falling from the air, and refreezing of bright ice on it, does not adequately explain the observations. Interpreting the observations as brine-related melting or refreezing also poses problems, but because brine may engulf salt grains or ice blocks, phase changes here could be influenced by factors other than temperature values, and could produce the observations.Analysis of absolute albedo changes indicates that the flow-like features are the darkest at their lower frontal end, sometimes darker than the dark spot from which they originate. A bright halo (white collar) also forms around these spots, possibly due to refreezing. Inside the observed larger spots an outer gray area surrounds the central darkest cores, which is about 10 cm lower than the surrounding bright CO2 ice. At those places, most or all of the CO2 ice deposited earlier has disappeared, and H2O ice is present. Observations of dark flow features moving on the top of this H2O rich layer suggest even if the flow features start as dry dune avalanches of rolling grains, their dark material heated by solar insolation is in contact with H2O ice and may produce brines.  相似文献   
54.
Increment cores were sampled from oak (Quercus robur) and ash (Fraxinus excelsior) growing at Elton, an area of the Cheshire Saltfield that has experienced significant subsidence and damage to the natural and built environments in the latter part of the twentieth century. Ring-width measurements for Elton trees permitted the construction of one main site chronology (Elton) and four sub chronologies (Elton A, Elton B, Elton C, Elton ASH). Ring-width difference between these and a control chronology identified periods of sustained growth reduction in oak trees commencing in AD 1859/1861, 1886 and 1934. Growth reductions after 1934 are related to watertable draw down caused by brine pumping from a concentration of nine boreholes at Elton, up to 2 km from tree sampling locations. Growth reductions in 1859/1861 and 1886 are likely to be the result of earlier phases of brine pumping in the Wheelock Valley, up to 5 km to the east of Elton, and these reductions correlate well with historic records of subsidence and pumping activity. Cessation of pumping in 1977 led to a lagged growth recovery in oak trees between 1981 and 1986, indicating that an artificial drought had been imposed on the Elton area for a period in excess off 100-y. This research demonstrates a hydrological separation of surface water and groundwater in an area where salt beds are overlain by till and that ring-width records of Q. robur can be used to reconstruct watertable variability and also the spatial impact of solution mining.  相似文献   
55.
56.
The salinity of groundwater increases with depth in the Canadian Shield (up to 1.3 kg/L of density). The existence of brine can be critically important for the safe geologic disposal of radioactive wastes, as dense brine can significantly retard the upward migration of radionuclides released from repositories. Static and flushing conditions of the deep brine are analyzed using a U-tube analogy model. Velocity reduction due to the presence of dense brine is derived under flushing conditions. A set of illustrative numerical simulations in a two-dimensional cross section is presented to demonstrate that dense brine can significantly influence regional groundwater flow patterns in a shield environment. It is implied from the results that (1) the existence of Shield brine can be an indicator of a hydrogeologically stable environment, (2) activities near ground surface may not perturb the stable groundwater environment in the deep brine region, and thus, (3) the deep brine region can be considered as a candidate geologic site for the safe disposal of waste. In addition to brine, other issues associated with long-term waste disposal, such as geological, glacial and seismic events, may need to be considered for the safe storage of spent nuclear fuel in a shield environment.  相似文献   
57.
马卡迪卡迪盐湖区为一现代干盐湖,盐湖以湖相碎屑沉积为主,在东侧的苏阿干盐湖赋存有高矿化孔隙卤水,通过对盐湖卤水系统的采样分析及综合研究,卤水主要化学组分为Na+和Cl-,其次为CO3^-2、HCO3^-,SO4^-2、K^+,矿化度平均为257.96g/L,卤水水化学类型为碳酸盐型;卤水组分与矿化度呈明显的正相关,表明卤水还未达到饱和阶段;受湖区构造及补给来源的影响,卤水的富集区位于研究区的西北部,同时也是矿化度最高的地区;KCl的含量在0.39%~0.99%之间,平均在0.65%,已超过液体钾盐矿的最低工业品位,分布面积约690km2,具有一定找矿前景。  相似文献   
58.
In this study, nineteen brine samples from the Qarhan Salt Lake (QSL) in western China were collected and analyzed for boron (B) and chlorine (Cl) concentrations, total dissolved solids (TDS), pH values and stable B isotopic compositions. The B concentrations and δ11B values of brines in the QSL range from 51.6 mg/L to 138.4 mg/L, and from +9.32‰ to +13.08‰, respectively. By comparison of B concentrations and TDS of brines in QSL with evaporation paths of brackish water, we found that B enrichment of brines primarily results from strong evaporation and concentration of Qarhan lake water. Combining with comparisons of B concentrations, TDS, pH values and δ11B values of brines, previously elemental ratios (K/Cl, Mg/Cl, Ca/Cl, B/Cl) and δ11B values of halite from a sediment core (ISL1A), we observe good correlations between B concentrations and TDS, TDS and pH values, pH and δ11B values of brines, which demonstrate that higher B concentrations and more positive δ11B values of halite indicate higher salinity of the Qarhan paleolake water as well as drier paleoclimatic conditions. Based on this interpretation of the δ11B values of halite in core ISL1A, higher salinity of the Qarhan paleolake occurred during two intervals, around 46–34 ka and 26–9 ka, which are almost coincident with the upper and lower halite-dominated salt layers in core ISL1A, drier climate phases documented from the δ18O record of carbonate in core ISL1A and the paleomoisture record in monsoonal central Asia, and a higher solar insolation at 30°N. These results demonstrate that the δ11B values of halite in the arid Qaidam Basin could be regarded as a new proxy for reconstructing the salinity record of paleolake water as well as paleoclimate conditions.  相似文献   
59.
Based on the geological and hydrogeological conditions along with dynamic changes of groundwater level,this paper analyzes the hydrodynamic characteristics of saltwater intrusion in the study area.According to monitoring data of groundwater quality,the distribution characteristics of macro component are analyzed,and then fuzzy comprehensive evaluation method is adopted to evaluate the impact of saltwater intrusion on groundwater environment.Concerning the influence degree of groundwater environment,the study area is divided into brine area,seriously influenced area,moderately influenced zone,slightly influenced zone and uninfluenced zone.The results can offer references for prevention and control of saltwater intrusion as well as the protection of water resources.  相似文献   
60.
The air–sea ice CO2 flux was measured over landfast sea ice in the Chukchi Sea, off Barrow, Alaska in late May 2008 with a chamber technique. The ice cover transitioned from a cold early spring to a warm late spring state, with an increase in air temperature and incipient surface melt. During melt, brine salinity and brine dissolved inorganic carbon concentration (DIC) decreased from 67.3 to 18.7 and 3977.6 to 1163.5 μmol kg−1, respectively. In contrast, the salinity and DIC of under-ice water at depths of 3 and 5 m below the ice surface remained almost constant with average values of 32.4±0.3 (standard deviation) and 2163.1±16.8 μmol kg−1, respectively. The air–sea ice CO2 flux decreased from +0.7 to −1.0 mmol m−2 day−1 (where a positive value indicates CO2 being released to the atmosphere from the ice surface). During this early to late spring transition, brought on by surface melt, sea ice shifted from a source to a sink for atmospheric CO2, with a rapid decrease of brine DIC likely associated with a decrease in the partial pressure of CO2 of brine from a supersaturated to an undersaturated state compared to the atmosphere. Formation of superimposed ice coincident with melt was not sufficient to shut down ice–air gas exchange.  相似文献   
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