The Sedimentary Characteristics and Environmental Significance of Saline Lake Shore in North Tibetan Plateau

Introduction Through the study of environmental change indicators:landform,strata sedimentary characteristics,mineralogy characteristics and Grain-size,magnetic susceptibility analysis for 3101 cm height profile of Dogai Coring salt lake shore in the northern of Tibet plateau,the conclusion is roughly obtained about six major climate change process:

Utilization and Exploitation of Lithium Resources in Salt Lakes and Suggestions for Development of Li Industries of China

1 Introduction Lithium and its compounds as a joint of rising industries new energy sources,new materials,and information technique have become more and more important recent years.Especially lithium ion batteries with bigger or smaller

Sedimentary Characteristics and Paleoenvironmental Records of Zabuye Salt Lake,Tibetan Plateau,since 128 ka BP

This paper for the first time reveals high-resolution core records of Zabuye Salt Lake in the interior of the Qinghai-Tibet Plateau. According to 1346 samples taken continuously, relatively accurate 14^C, U-series disequilibrium and ESR ages have been obtained, thus revealing that the lake core ages from 0 to 83.63 m of hole SZK02 are -800 to over 128 ka. In the paper, the lake core sedimentary characteristics （including the lithologies and mineral assemblages） are analyzed in detail and correlated with ostracod assemblages I to XX and sporopollen zones A to I, and on the basis of an integrated analysis of the δ^18O values of authigenic calcium-magnesium carbonate and environmental proxies of minerals, sporopollen and microfossils in the lake core, a correlation has been made of oxygen isotope change between this lake core and the Greenland GISP2 and GRIP and Guliya ice cores, and the climate of Zabuye Salt Lake since 128 ka BP is divided into the last interglacial stage （including substages e, d, c, b and a） of oxygen isotope stage （OIS） 5, early glacial stadial of the last glacial stage of OIS 4, interglacial stadial of the last glacial stage of OIS 3, late glacial stadial of the last glacial stage or Last Glacial Maximum of OIS 2 and postglacial state of OIS 1; in addition, 6 Heinrich （H6-H1） events, Younger Dryas event and 8.2 ka BP cold event have been recognized.

Progress and Prospects of Salt Lake Research in China

China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate （salt forming） have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits： the atlas （1：2500000） of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of ＂Continental Potash Deposition Theory＂; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCI production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production line, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, i.e. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond＂ the highest lithium production base at Zabuye Lake （4421 m）, Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture （Salt land agriculture） has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science ＂Salinology＂.

Regional Distribution and Prospects of Potash in China

China was formed by amalgamation of several small continental blocks （cratons）, micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China＇s marine and continental saline basins and salt, and potash, forming environment have some specific characteristics： multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China＇s major ancient saline basins occur in ＂quasi, cratons （continental block）＂; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China＇s salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.

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.

Phase Chemistry Study of the Zabuye Salt Lake Brine:Isothermal Evaporation at 15℃ and 25℃

Zabuye Salt Lake in Tibet,China is a carbonate-type salt lake,which has some unique characteristics that make it different from other types of salt lakes.The lake is at the latter period in its evolution and contains liquid and solid resources.Its brine is rich in Li,B,K and other useful minor elements that are of great economic value.We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15℃and 25℃.The crystallization sequence of the primary salts from the brine at 25℃is halite（NaCl）→aphthitalite （3K_2SO_4·Na_2SO_4）→zabuyelite（Li_2CO_3）→trona（Na_2CO_3·NaHCO_3·2H_2O）→thermonatrite （Na_2CO_3·H_2O）→sylvite（KCl）,while the sequence is halite（NaCl）→sylvite（KCl）→trona （Na_2CO_3·NaHCO_3·2H_2O）→zabuyelite（Li_2CO_3）→thermonatrite（Na_2CO_3·H_2O）→aphthitalite （3K_2SO_4·Na_2SO_4） at 15℃.They are in accordance with the metastable phase diagram of the Na~＋,K~＋-Cl^-, CO_3^（2-）,SO_4^（2-）-H_2O quinary system at 25℃,except for Na_2CO_3·7H_2O which is replaced by trona and thermonatrite.In the 25℃experiment,zabuyelite（Li_2CO_3） was precipitated in the early stage because Li_2CO_3 is supersaturated in the brine at 25℃,in contrast with that at 15℃,it precipitated in the later stage.Potash was precipitated in the middle and late stages in both experiments,while boron was concentrated in the early and middle stages and precipitated in the late stage.

Sr Isotope Geochemistry and Depositional Setting of Carbonate in Ordovician,Ordos Basin,China

China is in severe shortage of potash reserves,and the best way for breakthrough is to make potash exploration in marine salt basins.Erdos basin is so far the only Ordovician potash basin in the world.The Erdos basin is located west

Travertines in Dogai Coring Area of Tibet,China:Carbon,Oxygen and Strontium Isotopic Characteristics and Genetic Mechanism

1 Introduction Dogai Coring is a name of lake lied in the northern Tibet.There are a series of modern salt springs and theies travertines.All of salt springs have an anomaly of potassium,implying that springs water may dissolve evaporites from deep bed formation,which includes halite

Ecological Distribution and Significance of Metadiaptomus asiaticus Uljanirs,a Copepod Recently Found on the Qinghai-Tibetan Plateau

1 Introduction In 2006,plankton investigation was carried out in the lakes in Ali district,Tibet.7 planktonic crustaceans were identified and reported.Metadiaptomus asiaticus Uljanirs was reported for the first time on the QTP(Yuan et al.,2007).However,detailed data on this species,especially its ecological significance,were not mentioned.In this

Sedimentary Conditions of Evaporites in the Late Jurassic Xiali Formation,Qiangtang Basin：Evidence from Geochemistry Records

The Qiangtang Basin（QB）, located in the central Tibetan Plateau, is a Jurassic marine basin and one of the most important prospective salt resource belts in China. In recent decades, many outcrops of gypsiferous bed have been found in the Jurassic marine strata in the basin. Salt springs with abnormally high sodium（Na-＋） contents had been identified in the Late Jurassic Xiali Formation（Fm.） in the basin in the last years. However, to date, no potash or halite deposits have been identified in the QB. Gypsum outcrops and salt springs are very important signs in the investigation of halite and potash deposits. Therefore, the Xiali Fm. is a potentially valuable layer to evaluate for the possible presence of halite and potash deposits in the basin. However, few studies have explored the formation conditions of evaporites in the unit. Here, we present detailed geochemical records from the Yanshiping section related to the study of the formation conditions of evaporites in the Xiali Fm. of the QB. Climate proxies based on the obviously increased anion concentrations of SO4（2-） and Cl-- and the significant correlation coefficients of Ca2＋-SO42-（R = 0.985） and Na-＋-Cl--（R = 0.8974） reveal that the upper member of the Xiali Fm.（the upper Xiali Fm.） formed under an arid climate and evolved into the sulfate phase or early chloride phase. Provenance proxies based on the obviously increased K-＋ and Na-＋ ion concentrations and the significant correlation coefficient of Na-＋-Cl--（R = 0.8974） suggest that the upper Xiali Fm. featured optimal provenance conditions for the possible formation of halite deposits. The regression and the semi-closed tidal flat environment in the upper Xiali Fm. were favorable for the formation of potash and halite deposits. The low Mg-（2＋） /Ca-（2＋） values（mean value = 1.82） and significant Na-＋-Cl-- correlation coefficient（R = 0.8974） also suggest that the upper Xiali Fm. is the layer most likely to contain potential halite deposits. In addition, the macroscopic correlations of tectonism, provenance, paleoclimate, saliferous strata and sedimentary environment between the QB and the adjoining Amu Darya Basin in Central Asia reveal that the two basins shared similar geologic settings that were favorable for the formation of evaporites during the Late Jurassic. Therefore, the upper Xiali Fm. is a valuable layer to explore for halite deposit and may be potentially valuable in the future exploration for potash deposits in the QB.

Hydrochemistry of the Gasikule Salt Lake,Western Qaidam Basin of China

The Qaidam Basin is a large intermontane depression in Qinghai Province,China,which located on the northern margin of the Tibet plateau,and surrounded by the Qilian,Kunlun and Aljun mountains which rise to more than 5000m.Some 27 salt lakes occur within the basin,occupying an area of approximately 1500 km2.Additionally,there are extensive areas of dry playas.Together,the playas and salt lakes cover about one quarter of the total basin area.Whereas the western

Microbial Mats in Tibetan Hot Springs and their Contributions to the Cesium-bearing Geyserite Ore Formation

Microbial mats, mainly dominated by filamentous algae Calothrix and Oscillatoria, are well developed in Tibetan hot springs. A great number of fossil microorganisms, which existed as algae lamination in thermal depositional cesium-bearing geyserite in this area, are identified as Calothrix and Oscillatoria through microexamination and culture experiments. These microbial mats show the ability to accumulate cesium from spring water to the extent of cesium concentration of 0.46-1.03% cell dry weight, 900 times higher than that in water, and capture large numbers of cesium-bearing opal grain. Silicon dioxide colloid in spring water replaces and fills with the organism and deposits on it to form algae laminated geyserite after dehydration and congelation. Cesium in the microbial mats and opal grain is then reserved in the geyserite. Eventually, cesium-bearing algae laminated geyserite is formed. Study on cesium distribution in geyserite also shows that cesium content in algae lamination, especially in heavily compacted algae lamination, is higher than in the opal layer. For geyserite with no algae lamination or other organism structure, which is generally formed in spring water with low silicon content, cesium accumulation and cesium-bearing opal grain assembled by the microbial mats are also indispensable. After the microbial mats accumulating cesium from spring water, silicon dioxide colloid poorly replaces and fills with the organism to form opal grain-bearing tremellose microbial mats. The shape and structure of the organisms are then destroyed, resulting in cesium-bearing geyserite with no algae lamination structure after dehydration and congelation. It is then concluded that microbial mats in the spring area contribute to the enrichment of cesium in the formation of cesium-bearing geyserite, and a biological genesis of the geyserite, besides of the physical and chemical genesis, is likely.

Ostracodes from Recent Surface Deposits in Tibet,Response to Environmental Changes

1 Introduction Ostracodes are good materials for studying palaeoenvironmental evolution because of their sensitive response to environment changes.At present,the environmental implications of ostracodes are mainly based

Discovery of marine fossils in the upper part of the Permian Linxi Formation in Lopingian, Xingmeng area, China

Two important geological issues have a long history of debate in the Xingmeng area.The first concerns the final closure of the North China plate,Siberia plate and several intermediate massifs in the area,and the other concerns the folding and lifting of the Xingmeng Trough.Disagreements arise because of issues involving the tectonicpalaeogeographical environment of the Upper Permian deposits of the Linxi Formation.The Linxi Formation(Upper Permian)is generally considered to be either an exclusively continental deposit or separated into marineterrigenous facies deposited during the Lower to Middle Linxi Period and continental deposits in the Upper Linxi Period.However,in this study,large numbers of bryozoan and sponge spicule fossils were discovered for this first time in the thick limestone layers and lenses of the upper part of the Linxi Formation found in the Guandi section of Linxi county in eastern Inner Mongolia.At the same time,abundant bryozoan fossils were also found in sedimentary tuff slices that were collected from the upper part of the Taohuayingzi Formation from the Taohuayingzi section in Ar Horqin Banner,and abundant small connecting body crinoid stem fossils were found in the dark shale of the Yangjiagou Formation from the Yangjiagou section of Jiutai county,Jilin Province.These marine fossils provide the first evidence that the Xingmeng area was still a marine or mainly marine environment at the end of the late Permian.This not only provides conclusive evidence for the recognition of the above two major geological issues but also promotes changes in the approach towards research,exploration and development of oil and gas,shale gas(oil),and other mineral resources that are preserved in the late Permian layers of the Northeast-Xingmeng area.

Geomorphometric Features of the Alluvial Fans around the Chaka-Qinghai Lake in the Northeastern Tibetan Plateau

This article aims to study the geomorpometric features of alluvial fans since they act as a small-scale geomorphic unit response to tectonics and climate changes around the Chaka-Qinghai Lake area in the northeastern Tibetan Plateau. We quantitatively extracted geomorphic parameters, such as the surface area and slope of alluvial fans adjacent to the Qinghai Nan Shan and Ela Shan. Alluvial fans in the Chaka Lake partition area, south of the Qinghai Nan Shan, are featured by a small area and short length, but the largest slope. Geomorphic parameters of the alluvial fans in Ela Shan area are in- termediate in size, and the alluvial fans in the Qinghai Lake partition area north of Qinghai Nan Shan have the gentlest slope. Together with the regional faulting activity analysis, we suggest that the alluvial fans with the high slopes in the south of Qinghai Nan Shan are mainly controlled by the reverse faulting along the Qinghai Nan Shan faults, and the strike-slip movement of the Eia Shan fault zone plays a weak role. In contrast, due to the lack of active faults, the alluvial fans near the Qinghai Lake area north of the Qinghai Nan Shan only respond to regional erosion, transportation, and deposition proc- esses, thereby forming relatively gentle geomorphic units.

Caloric evaporation of the brine in Zangnan Salt Lake

Zangnan Salt Lake on the south of the Tibet is a type of carbonate lake with high concentrations of lithium,boron,and potassium and obviously it differs from seawater in its chemical composition.An experimental simulation of the caloric evaporation of the lake’s brine was conducted byfirst freezing the brine and then performing isothermal evaporation at 288.15 K.The freezing path and the physicochemical properties of the brine were determined.The crystallization sequence was natron,hydrohalite,halite,sylvite,zabuyelite,trona,aphthitalite,thermonatrite,and borax.Rubidium and cesium salts did not crystallized out but concentrated in the mother solution.The physicochemical properties(density,refractive index,conductivity,and pH)of the liquid phase changed as the evaporation progressed.In the beginning of the evaporation processes,the concentration of potassium ions in the liquid phase gradually increased but later it decreased.A peak value of 55.21 g/L was obtained when the evaporation was 88%complete.When the mineral aphthitalite began to crystallize;the concentra-tions of B2O3,Li+,Rb+,and Cs+gradually increased as the evaporation progressed.When the evaporation was 98%complete,their concentrations in the mother liquor were 40.77 g/L,4.838 g/L,400.17 mg/L and 31.95 mg/L,respectively.This essential fundamental study can provide an important reference for the comprehensive utilization of brines in Zangnan Salt Lake.