Sedimentary characteristics and depositional model of a Paleocene-Eocene salt lake in the Jiangling Depression,China

We studied the sedimentary characteristics of a Paleocene-Eocene salt lake in the Jiangling Depression through field core observation,thin section identification,scanning electron microscopy,and X-ray diffraction analysis.On the basis of sedimentary characteristics we have summarized the petrological and mineralogical characteristics of the salt lake and proposed 9 types of grade IV salt rhythms.The deposition shows a desalting to salting order of halite-argillaceous-mudstone-mud dolostonemud anhydrock-glauberite-halite.The relationship among grade IV rhythms,water salinity and climate fluctuations was analyzed.Based on the analysis of the relationship between boron content and mudstone color and by combining the mineralogy and sedimentary environment characteristics,we propose that the early and late Paleocene Shashi Formation in the Jiangling Depression was a paleolacustrine depositional environment with a high salt content,which is a representation of the shallow water salt lake depositional model.The middle Paleocene Shashi Formation and the early Eocene Xingouzui Formation were salt and brackish sedimentary environments with low salt content in a deep paleolake,which represents a deep salt lake depositional model.

Isotope Dating of the Potash and Rock Salt Deposit at Bamnet Narong, NE-Thailand

Bamnet Narong is located in northeastern Thailand (Chaiyaphum Province). It is the largest salt mine in the country and has been mined for decades. The landscape in this part of Thailand is characterised by a low plateau, which is called the Khorat Plateau. The plateau is divided into two basins by the Phu Phan Range, the Sakhon Nakhon Basin in the north and the Khorat Basin in the south. The analysed potashes and rock salts are deposited in the Maha Sarakham Formation, which represents the salt-bearing strata of the Khorat Basin. The stratigraphic age of this deposit has been debated since the late 1960’s. The assigned ages range from Mid-Cretaceous to Late Cretaceous and up to the Eocene. In this study different isotopic dating systems (Rb-Sr, Sr-Sr, K-Ar and K-Ca) were applied. The stratigraphic age for the time of deposition was confirmed to be Mid Cretaceous (Cenomanian). Furthermore, the homogeneity of the carnallites was investigated in order to trace a possible redistribution of rubidium.

Connections between Evaporite Deposition and Glacial Periods since the Middle Pleistocene in Salt Lakes in the Western Qaidam Basin, China

The Quaternary was the main evaporite deposition period in the Qaidam Basin(QB), but the correlation between the evaporite deposition period and the glacial period is still unclear. In this study, the research objects are primarily evaporite-bearing strata in a 461.58 m-long drill core in the QB. X-ray powder diffraction(XRD) and scanning electron microscopy(SEM) were applied to study the evaporite minerals, U-Th dating being applied to construct the ~(230)Th geochronological framework. Evaporite deposition from Marine Isotope Stage(MIS) 15 to MIS 4 in the borehole was reconstructed via mineralogical and geochronological data. The evaporite minerals are mainly halite(NaCl), mirabilite(Na_(2)SO_(4)·10H_(2)O), thenardite(Na_(2)SO_(4)) and gypsum(CaSO_(4)·2H_(2)O). A total of 9 effective ~(230)Th data points, ranging from 492.5 ± 43.0 ka to 62.0 ± 11.9 ka, were obtained. The depositional age of the earliest halite layer in the borehole is 592.5–563.0 ka. There were mirabilite deposits in the QB during the cold glacial environment of MIS 6. During MIS 4, the study area desiccated, with mirabilite and halite being deposited. This study suggests that mirabilite is an indicator mineral for the glacial environment in the QB, while halite deposition does not correspond well to glaciation.

Classification and mineralization of global lithium deposits and lithium extraction technologies for exogenetic lithium deposits

A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous novel lithium resources. Given the presence of varied classification criteria for lithium resources presently, this study further ascertained and classified the lithium resources according to their occurrence modes, obtaining 10 types and 5 subtypes of lithium deposits(resources) based on endogenetic and exogenetic factors. As indicated by surveys of Cenozoic exogenetic lithium deposits in China and abroad,the formation and distribution of the deposits are primarily determined by plate collision zones, their primary material sources are linked to the anatectic magmas in the deep oceanic crust, and they were formed primarily during the Miocene and Late Paleogene. The researchers ascertained that these deposits,especially those of the salt lake, geothermal, and volcanic deposit types, are formed by unique slightly acidic magmas, tend to migrate and accumulate toward low-lying areas, and display supernormal enrichment. However, the material sources of lithium deposits(resources) of the Neopaleozoic clay subtype and the deep brine type are yet to be further identified. Given the various types and complex origins of lithium deposits(resources), which were formed due to the interactions of multiple spheres, it is recommended that the mineralization of exogenetic lithium deposits(resources) be investigated by integrating tectono-geochemistry, paleoatmospheric circulation, and salinology. So far, industrialized lithium extraction is primarily achieved in lithium deposits of the salt lake, clay, and hard rock types. The lithium extraction employs different processes, with lithium extraction from salt lake-type lithium deposits proving the most energy-saving and cost-effective.

Geological characteristics and genesis of subbottom pinnoite deposit of Da Qaidam salt lake in Qaidam Basin

Da Qaidam salt lake is known for its both liquid and solid boron resource.Data from previous investigation of the Da Qaidam salt lake provided a comparable framework for this study that focused on investigating the section beneath the bottom of the perennial salt lake,including the timing,

Electrochemical co-deposition of magnesium based alloy from molten salts

Magnesium based alloys with aluminum and zinc were obtained through electrochemical co-deposition from LiCl-NaCl-MgCl2 melt. The possibility of electrochemical co-deposition was discussed in detail by electro-analytical methods including cyclic voltametry,square wave voltametry,and chronopotentiometry. The co-deposition happens when the concentration of aluminum and zinc ions is kept at low value and the current density is high enough. The components of alloy elements can be controlled by fixing the components of the feeding salts. A laboratory experiment of the preparation by step-current co-deposition was also performed and certain compositions of the Mg-Al,and Mg-Zn were obtained. The alloys obtained from the co-deposition show a typical as-cast microstructure. The best conditions of electrolysis such as temperature,amount of addition and mode of feeding were discussed in detail.

On Biochemical Formation of Salt Deposits

A water/salt system in an evaporative environment is both a physicochemical region and a biological one. All the parameters of the system, such as the salinity, temperature and CO2 partial pressure, are affected by halophilic bacteria. The system controls salt deposition but is modified by an accompanying ecological system; therefore it should be called a water/salt/biological system. Salt minerals result from accumulation of the remains of bacteria/algae, namely, bacteria/algae formation; whereas biological, biophysical and biochemical processes provide full evidence for organic involvement. Consequently, salt deposits should not be called purely chemical but biological/chemical ones. This new argument supplements and develops the traditional idea and helps perfect the mineralization theory of salts and even general deposits, thus giving guidance to prospecting for salt deposits.

Analyses on Temporal and Spatial Variation Characteristics of Erosion and Deposition in the Front Edge of Salt Marsh Wetland

Taking Yancheng Nature Reserve Salt Marsh as the research object,the remote sensing images from 2005 to 2020 were interpreted by using remote sensing and geographic information system technology.In this paper,the temporal and spatial variation characteristics of erosion and deposition in the front edge of salt marsh wetland were analyzed.The influence of sea level rise on the annual change of salt marsh area was analyzed.The characteristics of flow and sediment movement in salt marsh and the causes of erosion and deposition in front of salt marsh were analyzed.The results showed that:(1)During 2005-2007,the sea level was relatively low,and Spartina alterniflora in salt marsh expanded to the sea.Since 2007,the front edge of salt marsh wetland has coexisted with erosion and deposition.From 2008 to 2010,the front edge of salt marsh wetland once again showed a trend of comprehensive deposition to the sea side.From 2010 to 2012,the erosion of salt marsh wetland was serious.From 2012 to 2020,the front edge of salt marsh wetland in the range of 9 km south of Xinyang estuary was eroded.(2)The correlation analysis was carried out between the area of salt marsh wetland and sea level rise.Spartina alterniflora is easily affected by sea level change,owing to it having a low ecological niche.With the rise of sea level,the area of salt marsh has been decreasing since 2013.(3)In the front sea area of salt marsh wetland,the maximum velocity of the ebb and flood can reach the threshold velocity during the spring tide.The sediment starts to move at water depth of 10 m under wave actions.Owing to wave stirs up sediment and current transports the sediment,resuspended sediment causes the erosion of marsh-edge scarps.

Numerical Simulation of Contamination Accumulation Characteristics of Composite Insulators in Salt Fog Environment

To investigate the fouling characteristics of the composite insulator surface under the salt fog environment,the FXBW-110/120-2 composite insulator was taken as the research object.Based on the field-induced charge mechanism,the multi-physical field coupling software COMSOL was used to numerically simulate the fouling characteristics,explored the calculation method of ESDD,and demonstrated its rationality.Based on this method,the pollution characteristics of the composite insulator under the pollution fog environment were studied,and the influence of wind speed,droplet size,and voltage type on the pollution characteristics of the composite insulator was analyzed.The results showed that:with the increase in wind speed,the amount of accumulated pollution of insulator increases in the range of droplet size,and the relationship between wind speed and accumulated pollution is approximately linear;at the same wind speed,the amount of accumulated pollution increases with the increase of droplet size under the action of DC voltage;when there is no voltage,the amount of dirt on the upper surface of the insulator is more than that on the lower surface,while it is the opposite under DC voltage.

新疆库车盆地古近纪—新近纪盐湖成钾与靶区预测

库车前陆盆地位于塔里木盆地北部,属于副特提斯域,古近纪受副特提斯海海水补给,古近纪—新近纪发育巨厚蒸发岩。研究显示,库车盆地始新世和中新世古盐湖卤水已演化至钾盐析出阶段,在地层中广泛发现了原生钾盐矿物,如钾石盐、光卤石、杂卤石等;通过岩芯岩屑地球化学及矿物学分析,基本确定了至少3个富钾层或成钾层位,其中始新统中上部两个和中新统中上部一个,钾离子含量最高达3%,另外,上新统可能存在一个成钾层位。本文在综述此前库车盆地构造、蒸发岩、盐类矿物学、地球化学与盐湖沉积等研究基础上,建立了新的库车盆地古盐湖构造-沉积演变、成钾模式;提出了4个钾盐成矿区带,即北部克拉苏成矿带、中部秋里塔克成矿带、南部沙雅构造沉降成矿带以及东部阳霞凹地成钾区,这些关键认识为库车盆地的钾盐勘查提供了重要的理论和科学依据。

全新世以来察尔汗盐湖沉积物的OSL年代学研究

察尔汗盐湖沉积物记录了柴达木盆地晚更新世以来的环境演化信息,但全新世以来沉积剖面的研究比较稀少且相关年代数据也比较缺乏。在察尔汗盐湖别勒滩区段东部,别勒滩区段西部和达布逊区段东部的沉积剖面中各发现2层细碎屑夹层,采集了相应的光释光样品,以研究察尔汗盐湖全新世时期的沉积年代。结果表明,察尔汗盐湖达布逊区段东部剖面(DBX)的2个碎屑层分别形成于6.2 ka(8.90 m)和2.8 ka(1.96 m),别勒滩区段东部剖面的2个碎屑层分别形成于2.9 ka(3.20 m)和0.9 ka(1.40 m),别勒滩区段西部剖面的2个碎屑层分别形成于2.4 ka(3.10 m)和0.7 ka(1.50 m)。由于晚第四纪盐湖沉积松散且易溶造成样品的成分及来源复杂等影响,造成了剖面OSL数据远小于14C、U-Th测年数据(8~9 ka)。3个剖面沉积速率计算表明,察尔汗盐湖达布逊区段沉积速率大于别勒滩区段,而别勒滩区段东部的沉积速率高于西部,察尔汗盐湖与东台吉乃尔盐湖的沉积速率整体上保持一致。

Overexpression of Proline Transporter Gene Isolated from Halophyte Confers Salt Tolerance in Arabidopsis

Proline is one of the most important and widespread osmolyte which functions in adaptation to adverse environmental stresses in many organisms. Also it is an important carbon and nitrogen resource in higher plants. Metabolism of proline has been elucidated in many plant species. However, transport of proline was poorly characterized although transport system plays an important role in proline distribution in different tissues. We isolated one full_length cDNA encoding proline transporter from the typical halophyte: Atriplex hortensis L. through cDNA library screening and 5′_RACE. The deduced amino acid sequence had eleven transmembrane domains, showed 60%-69% similarities to other ProTs and the gene was designated AhProT1. In the phylogenetic tree, higher plants' ProTs, e.g. AhProT1, showed more similar to ProP from microorganisms than ProT from mammalians. AhProT1 gene was transformed into Arabidopsis thaliana under 35S promoter. In MS medium containing [U_ 14 C] proline, AhProT1 + plants were able to accumulate much more radiolabeled proline in the roots than control plants. In MS medium containing different concentrations of NaCl, AhProT1 + plants could endure 200 mmol/L NaCl and keep development and biomass increase with proline supply, whereas control plants died back at 150 mmol/L NaCl.

轴流压气机叶片表面盐雾颗粒沉积仿真

为研究轴流压气机在运行过程中盐雾颗粒在叶片表面的碰撞点和碰撞量分布,基于拉格朗日离散相(DPM)模型对不同旋转速度、不同盐雾粒径条件下压气机叶片表面盐雾颗粒碰撞状态进行了仿真,获取了压气机叶片表面盐雾颗粒碰撞分布规律;基于压气机轴对称结构开发了叶片表面盐雾碰撞位置及碰撞量的统计软件,对叶片表面盐雾颗粒碰撞情况进行了统计。结果表明:盐雾碰撞位置受压气机通道形状与盐雾颗粒受力大小影响,盐雾颗粒与叶片的碰撞主要发生在叶盆面,叶背面只有少量的盐雾颗粒能够到达;盐雾颗粒在叶片表面沉积的覆盖面积与盐雾颗粒直径呈正相关,在最大状态下且盐雾颗粒直径为5μm时,转子和静子叶盆表面盐雾颗粒沉积的覆盖面积分别为59.3%和55.3%;盐雾颗粒在叶片表面沉积的覆盖面积与压气机转速呈正相关,在慢车状态下且盐雾颗粒直径为5μm时,转子和静子叶盆表面盐雾颗粒沉积的覆盖面积分别为57%和42.9%。

密西西比河谷型(MVT)铅锌矿床与蒸发岩的成因关系

MVT铅锌矿床的形成与蒸发岩关系密切,但在蒸发盐矿物发生溶解或转变为其他矿物而“消失”时,人们常忽视其曾经存在。本文基于前人研究,对蒸发岩的转变、识别特征及其与MVT铅锌成矿流体来源、硫来源及储矿构造三个方面的关系进行综述。其中,MVT矿床迁移铅锌的盆地卤水主要来自蒸发海水,少量来自蒸发岩的溶解,区域上蒸发岩的发育可指示该区具有成矿流体的发育条件。铅锌金属硫化物中的硫均来自于硫酸盐还原作用,而石膏和硬石膏等蒸发盐矿物是硫酸盐的重要提供者。蒸发岩溶解垮塌利于形成角砾岩与垮塌空间,铅锌矿化可赋存于角砾岩内或其邻近岩层中;盐底辟构造会形成有利于流体聚集和矿质沉淀的构造/化学圈闭,铅锌矿化赋存于底辟体顶部冠岩、边部过渡层和围岩、直立的底辟角砾筒或侧向底辟形成的穹隆体顶部。此外,蒸发盐矿物的假晶、残留的蒸发盐矿物是“消失”蒸发岩存在的直接证据,钠长石和方柱石、正延性玉髓/燧石、富碱土元素双锥状石英等,可指示蒸发岩曾经存在;蒸发岩溶解垮塌构造具有顺地层延伸长等特点,盐底辟构造具有穿层及角砾来自下部层位等特点,是可以协助识别蒸发岩的相关构造。可以看出,区域地层记录有蒸发沉积环境是MVT铅锌成矿必要条件,蒸发岩溶解垮塌和底辟构造是重要找矿目标。

超大型海水冷却塔塔群飘滴及盐沉积数值模拟研究

针对核电项目大型海水冷却塔,采用三维数值模型,结合厂址气象数据、冷却塔设计参数、总图布置以及周围环境特征,研究了超大型自然通风海水冷却塔在建筑物、环境风相互作用下的冷却塔飘滴扩散迁移特征和盐沉积量。结果表明,当环境风向与塔排平行时,出口热空气相互叠加形成一股气流,有利于减少飘滴和盐沉积对环境的影响,粒径大于550μm的飘滴不能从高位冷却塔出口逸出,6台核电机组正常运行工况时,盐沉积量一般不会对植物造成严重损坏。

某凝析油稳定塔塔底重沸器2205管束的腐蚀失效原因

某油田凝析油稳定塔塔底重沸器2205双相不锈钢换热管束发生开裂失效。通过宏观检查、化学成分和组织检查、残余应力测试、断口分析以及应力腐蚀试验系统分析了其失效原因。结果表明:换热管束失效多集中在U形弯区域,裂纹多呈现环向开裂特征;在失效管束U形弯区域存在残余拉应力,其最大值达到262 MPa;断口表面可见明显的解理和准解理特征,以及二次裂纹。综合分析结果可知管束失效原因为高温-结盐-氧引起的氯化物应力腐蚀开裂。

柴达木盆地盐类及地下水矿床成矿系列与找矿方向

新生代以来,柴达木盆地形成了复杂的构造体系及一系列相对独立的构造、成矿单元。柴达木盆地不同的构造单元因沉积环境与成矿条件的差异,在第四系浅层盐湖区、更新统冲洪积扇区、古近系—新近系圈闭构造区等特定的时空范围形成了赋存状态、矿物组合等相对独特的矿产。对柴达木盆地盐类及地下水资源时空分布特征、成矿作用及成矿地质背景进行了归纳研究,划分了盆地盐类及地下水矿床成矿系列。以成矿系列理论为指导,结合柴达木盆地最新的勘查研究成果,对盆地演化、盐类成矿单元、矿产时空分布及成矿类型等进行梳理,将柴达木盆地盐类及地下水矿床划分为3个成矿系列、6个成矿亚系列、15个矿床式。根据矿床自然分类及矿床成矿系列“全位成矿、缺位找矿”的预测思维,提出了柴达木盆地盐类及地下水矿产的找矿方向。

海上盐雾环境对风力机翼型气动性能的影响

为探究海上潮湿盐雾环境变化对海上风机翼型气动性能产生的影响,采用组分运输模型与离散相模型对海上盐雾环境进行环境模型建立和参数设定,结合壁面沉积模型用户自定义函数,以NACA4415翼型为研究对象进行数值模拟。研究发现:翼型的升阻力系数随着盐雾浓度的增加而增大,随着空气湿度的升高而减小;颗粒在翼型表面0.2~0.8弦长处均匀分布,在靠近前缘处沉积较少,尾缘沉积较多;速度的增加会降低颗粒的沉积率,翼型攻角升高会改变表面速度分布,影响翼型表面颗粒沉积率;空气湿度升高会减少盐雾颗粒在翼型表面的沉积量,在沉积量较多的区域降低更加明显,并且随着攻角的增大,湿度的影响逐渐减小。

秦山核电站海域有害盐在带温核级材料表面沉积实验设计

含Cl有害盐在服役构件表面的沉积量,是影响服役构件腐蚀进程的重要因素。秦山核电站临海而建,面临含Cl有害盐沉积引起的腐蚀问题。该文通过实地环境调研,并根据调研结果开展实验室盐雾沉积实验设计,结果表明:以ASTM D1141-98(2021版)标准中的人工海水Cl元素含量为基准,将秦山核电站海域海水各化合物含量乘以4.075 26进行放大,可得到符合ASTM标准设计的盐雾沉积用有害盐模拟溶液成分。之后,该文进一步开展90℃带温核级材料表面有害盐沉积实验,探究临海服役环境下,有害盐在秦山核电站乏燃料贮罐材料(带温核级材料)表面的沉积规律,为开展实际服役环境下的核电站材料服役寿命评估、服役性能评价提供一种实验室设计思路与借鉴。

西藏扎布耶盐湖泻湖湾积盐综合循环利用

扎布耶盐湖位于西藏自治区(简称西藏),地处日喀则市仲巴县,是富含锂、钾和钠的大型盐湖矿床。针对泻湖湾的积盐进行资源勘查,开展溶盐试验,然后提出积盐回湖的综合循环利用方案。经资源勘查,目前,泻湖湾内的积盐暂不具备开发利用价值。未来,要结合实际生产需要和外部条件变化,合理选择积盐回湖时机。