New data on microelement and isotope composition of thermal springs in Tajikistan

This article provides detailed information about the geological setting and the chemical composition of some thermal springs (Garm-Chashma, Firuza-MGU, Tandykul, Obigarm, Khojaоbigarm) located within the Pamirs and the Tien Shan mountain systems. This is the first report describing the micro components data for investigated springs obtained by the ICP-MS method. The calculated ratios of B:Cl, B:Br and Li:Rb:Cs allow to define the genesis of the studied thermal springs. New data on the contents of 18O and D indicate that the studied thermal waters are most likely meteoric, while a slight drift from the meteoric water line is the result of isotope fractionation in water-rock-gas processes. The estimated subsurface temperatures for these thermal waters vary from 136 °C to 240 °C based on the K:Na geothermometer.

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Epithermal Fluorite Deposits in Transbaikalia (Geochemical Features, Sources of Matter and Fluids, and Genesis)

Russian Geology and Geophysics ◽

10.2113/rgg20194128 ◽

2021 ◽

Vol 62 (4) ◽

pp. 415-426

Author(s):

E.I. Lastochkin ◽

G.S. Ripp ◽

D.S. Tsydenova ◽

V.F. Posokhov ◽

A.E. Murzintseva

Keyword(s):

Meteoric Water ◽

Isotope Composition ◽

Spatial Proximity ◽

Thermal Waters ◽

Sr Isotope ◽

Light Isotope ◽

Geochemical Parameters ◽

Nd Systems ◽

Deep Source ◽

The Impact

Abstract —We consider the isotope-geochemical features of epithermal fluorite deposits in Transbaikalia, including the REE compositions, Sr isotope ratios, Sm–Nd systems, and isotope compositions of oxygen, carbon, hydrogen, and sulfur. The 87Sr/86Sr ratios in fluorites are within 0.706–0.708, and the εNd values are negative. Oxygen in quartz, the main mineral of the deposits, has a light isotope composition (δ18O = –3.4 to +2.6‰), and the calculated isotope composition of oxygen in the fluid in equilibrium with quartz (δ18O = –9 to –16‰) indicates the presence of meteoric water. The latter is confirmed by analysis of the isotope compositions of oxygen and hydrogen in gas–liquid inclusions in fluorites from three deposits. These isotope compositions are due to recycling caused by the impact of shallow basic plutons. The isotope composition of sulfur indicates its deep source. During ascent, sulfur became enriched in its light isotope (δ34S = –1.8 to –7.7‰). We assess the association of fluorite ores with basaltoids widespread in the study area. The isotope and geochemical parameters suggest their spatial proximity. Probably, the basaltoids were responsible for the recycling of meteoric water. It is shown that the epithermal fluorite deposits formed by the same mechanism as fissure–vein thermal waters in western Transbaikalia.

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Long-Term Isotope Records of Precipitation in Zagreb, Croatia

Water ◽

10.3390/w12010226 ◽

2020 ◽

Vol 12 (1) ◽

pp. 226 ◽

Cited By ~ 11

Author(s):

Ines Krajcar Bronić ◽

Jadranka Barešić ◽

Damir Borković ◽

Andreja Sironić ◽

Ivanka Lovrenčić Mikelić ◽

...

Keyword(s):

Meteoric Water ◽

Isotope Composition ◽

Eastern Mediterranean ◽

Meteorological Data ◽

Precipitation Amount ◽

Monthly Precipitation ◽

Air Masses ◽

Water Line ◽

Meteoric Water Line

The isotope composition of precipitation has been monitored in monthly precipitation at Zagreb, Croatia, since 1976. Here, we present a statistical analysis of available long-term isotope data (3H activity concentration, δ2H, δ18O, and deuterium excess) and compare them to basic meteorological data. The aim was to see whether isotope composition reflected observed climate changes in Zagreb: a significant increase in the annual air temperature and larger variations in the precipitation amount. Annual mean δ18O and δ2H values showed an increase of 0.017‰ and 0.14‰ per year, respectively, with larger differences in monthly mean values in the first half of the year than in the second half. Mean annual d-excess remained constant over the whole long-term period, with a tendency for monthly mean d-excess values to decrease in the first half of the year and increase in the second half due to the influence of air masses originating from the eastern Mediterranean. Changes in the stable isotope composition of precipitation thus resembled changes in the temperature, the circulation pattern of air masses, and the precipitation regime. A local meteoric water line was obtained using different regression methods, which did not result in significant differences between nonweighted and precipitation-weighted slope and intercept values. Deviations from the Global Meteoric Water Line GMWL (lower slopes and intercepts) were observed in two recent periods and could be explained by changes in climate parameters. The temperature gradient of δ18O was 0.33‰/°C. The tritium activity concentrations in precipitation showed slight decreases during the last two decades, and the mean A in the most recent period, 2012–2018, was 7.6 ± 0.8 Tritium Units (TU).

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Geochemical characterisation of the thermo-mineral waters of Greece

Environmental Geochemistry and Health ◽

10.1007/s10653-021-01001-1 ◽

2021 ◽

Author(s):

Lorenza Li Vigni ◽

Kyriaki Daskalopoulou ◽

Sergio Calabrese ◽

Konstantinos Kyriakopoulos ◽

Francesco Parello ◽

...

Keyword(s):

Meteoric Water ◽

Major Ions ◽

Mineral Waters ◽

Thermal Waters ◽

Rock Interaction ◽

Water Line ◽

Low Salinity ◽

Meteoric Water Line ◽

Of Greece ◽

Temperature Water

AbstractGeothermal areas of Greece are located in regions affected by recent volcanism and in continental basins characterised by elevated heat flow. Many of them are found along the coast, and thus, water is often saline due to marine intrusion. In the current study, we present about 300 unpublished and literature data from thermal and cold mineral waters collected along Greece. Samples were analysed for major ions, Li, SiO2 and isotopes in water. Measured temperatures range from 6.5 to 98 °C, pH from 1.96 to 11.98, while Total Dissolved Solutes (TDS) from 0.22 to 51 g/L. Waters were subdivided into four main groups: (1) thermal; (2) cold; (3) acidic (pH < 5); and (4) hyperalkaline (pH > 11). On statistical basis, thermal waters were subdivided into subgroups according to both their temperature [warm (< 29 °C), hypothermal (29–48 °C), thermal (48–75 °C) and hyperthermal (> 75 °C)] and TDS [low salinity (< 4 g/L), brackish (4–30 g/L) and saline (> 30 g/L)]. Cold waters were subdivided based on their pCO2 [low (< 0.05 atm), medium (0.05–0.85 atm) and high (> 0.85 atm)]. δ18O–H2O ranges from − 12.7 to + 2.7‰ versus SMOW, while δ2H–H2O from − 91 to + 12‰ versus SMOW being generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Positive δ18O shifts with respect to the former are mostly related to mixing with seawater, while only for a few samples these shifts point to high-temperature water–rock interaction processes. Only a few thermal waters gave reliable geothermometric estimates, suggesting reservoir temperatures between 80 and 260 °C.

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Behavior of the 238U, 235U, and 234U isotopes at weathering of volcanic rocks with u mineralization: a case study at the Tulukuevskoe deposit, Eastern Transbaikalia

Петрология ◽

10.31857/s0869-5903274446-467 ◽

2019 ◽

Vol 27 (4) ◽

pp. 446-467

Author(s):

I. V. Chernyshev ◽

V. N. Golubev ◽

A. V. Chugaev ◽

G. V. Mandzhieva ◽

B. I. Gareev

Keyword(s):

Aqueous Phase ◽

Isotope Fractionation ◽

Isotope Composition ◽

Volcanic Rocks ◽

Mineral Phases ◽

Icp Ms ◽

Eastern Transbaikalia ◽

Uranium Minerals ◽

Fractionation Mechanism

The trend fractionation of the 238U and 235U isotopes and the extent of this process at the oxidative weathering of uranium minerals were evaluated by studying the variations in the U isotope composition of rocks, minerals, and fracture waters sampled in the quarry of the broadly known Tulukuevskoe uranium deposit in the Streltsovskoe ore field, eastern Transbaikalia. In the rock block in question, fine uranium minerals disseminated in the rocks were weathered under the effect of oxidizing fracture waters. Uranium isotope composition was measured in 22 water samples, eleven samples of the mineralized rocks, and eight uranium minerals. High-precision (±0.07‰, 2SD) measurements of the 238U/235U were carried out by MC-ICP-MS, using a 233U–236U double spike. The results involve the 238U/235U and 234U/238U ratios and the overall range of the δ238U variations determined in the rocks and waters (from –0.13 to –1.0‰ and from –0.22 to –0.59‰, respectively). Interaction between the waters and rocks induces U(IV) → U(VI) oxidation, U(VI) transfer into the aqueous phase, and 0.15–0.28‰ enrichment of U dissolved in the water in the 235U isotope. When the pitchblende is replaced by U(VI) minerals, the 238U and 235U isotopes also fractionate with ~0.3‰ enrichment of the younger U(VI) mineral phases in the light 235U isotope. The 238U/235U and 234U/238U ratios are proved to correlate, and hence, the fractionation of the 238U and 235U isotopes and the enrichment of the aqueous phase in the light 235U isotope proceed simultaneously with the well known shift in equilibrium the 238U–234U system with the accumulation of excess amounts of the 234U in the aqueous phase. Uranium leaching from uranium minerals, which is associated with the enrichment of the aqueous phase in excess amounts of the 234U isotope, can be viewed as a process that controls isotope fractionation in the 238U–235U system. This should be taken into account in describing the fractionation mechanism of the 238U and 235U isotopes at U(IV) → U(VI) oxidation. The fractionation of the 238U and 235U isotopes, which results in the isotopic "lightening" of U in the aqueous phase, largely controlled the complicated distribution pattern of the 238U/235U ratio in the quarry. In addition to isotope fractionation, this distribution was likely also affected by isotope exchange between uranium dissolved in the water and uranium in the finely dispersed minerals. The isotopically light uranium of the water could participate in forming U(VI) minerals at lower levels of the quarry.

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Stable isotope composition of precipitation as signal of possible climate change: the case of the mountain Učka (Northern Adriatic, Croatia)

10.5194/egusphere-egu21-164 ◽

2021 ◽

Author(s):

Diana Mance ◽

Ema Topolnjak ◽

Anita Crnov ◽

Davor Mance ◽

Maja Radišić ◽

...

Keyword(s):

Climate Change ◽

Meteoric Water ◽

Isotope Composition ◽

Annual Rainfall ◽

Precipitation Regime ◽

Altitude Effect ◽

Northern Adriatic ◽

Water Line ◽

Meteoric Water Line ◽

Cold Part

The highest average annual rainfall in Croatia is in the Northern Adriatic, with some parts of the region receiving more than 2000 mm per year. Characteristics of the region&#8217;s weather are periods of intense rain alternating with dry periods in which the amount of precipitation can be negligible for more than a month. The area's water supply relies on karst groundwater sources that are primarily fed by Mediterranean precipitation. The aforementioned precipitation regime results in high groundwater yields in the cold part of the hydrological year and substantially decreased water quantities in the summer months. Under such specific conditions, it is of considerable importance to find out about the potential for climate change in order to ensure timely adjustment of the management and use of natural sources of water.We present a comparison of the isotopic composition of precipitation collected on the mountain U&#269;ka in periods 2008-2011 and 2019-2020. Rain gauges were located on a vertical gradient from sea level up to nearly 1400 m. Unlike&#160;the isotopic altitude effect that did not change significantly compared to the one reported for the first period (Roller-Lutz et al, 2013), the weighted means of isotopic values were more positive in the second period.&#160; For the cold part of the hydrological year, local meteoric water line has recently moved to higher values, indicating the sources of precipitation from drier Mediterranean regions. Local meteoric water line for the warm part of the last hydrological year, indicates presence of increased evaporation and thus confirms lower precipitation amounts.&#160;Roller-Lutz Zvjezdana, Mance Diana, Hunjak Tamara, Lutz Hans O. (2013) On the isotopic altitude effect of precipitation in the Northern Adriatic (Croatia), Isotopes in Hydrology, Marine Ecosystems and Climate Change Studies. Vol. I. Proceedings of an International Symposium&#160;This work was supported by the University of Rijeka as part of the research project uniri-pr-prirod-19-24.

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Contrasting Water Use Strategies of Tamarix ramosissima in Different Habitats in the Northwest of Loess Plateau, China

Water ◽

10.3390/w12102791 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2791

Author(s):

Pengyan Su ◽

Mingjun Zhang ◽

Deye Qu ◽

Jiaxin Wang ◽

Yu Zhang ◽

...

Keyword(s):

Soil Water ◽

Water Use ◽

Loess Plateau ◽

Meteoric Water ◽

Water Source ◽

Water Sources ◽

Tamarix Ramosissima ◽

Water Line ◽

Meteoric Water Line ◽

Utilization Ratio

As a species for ecological restoration in northern China, Tamarix ramosissima plays an important role in river protection, flood control, regional climate regulation, and landscape construction with vegetation. Two sampling sites were selected in the hillside and floodplain habitats along the Lanzhou City, and the xylems of T. ramosissima and potential water sources were collected, respectively. The Bayesian mixture model (MixSIAR) and soil water excess (SW-excess) were applied to analyze the relationship on different water pools and the utilization ratios of T. ramosissima to potential water sources in two habitats. The results showed that the slope and intercept of local meteoric water line (LMWL) in two habitats were smaller compared with the global meteoric water line (GMWL), which indicated the existence of drier climate and strong evaporation in the study area, especially in the hillside habitat. Except for the three months in hillside, the SW-excess of T. ramosissima were negative, which indicated that xylems of T. ramosissima are more depleted in δ2H than the soil water line. In growing seasons, the main water source in hillside habitat was deep soil water (80~150 cm) and the utilization ratio was 63 ± 17% for T. ramosissima, while the main water source in floodplain habitat was shallow soil water (0~30 cm), with a utilization ratio of 42.6 ± 19.2%, and the water sources were different in diverse months. T. ramosissima has a certain adaptation mechanism and water-use strategies in two habitats, and also an altered water uptake pattern in acquiring the more stable water. This study will provide a theoretical basis for plant water management in ecological environment protection in the Loess Plateau.

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Triple Isotope Fractionation Exponents of Elements Measured by MC-ICP-MS—An Example of Mg

Analytical Chemistry ◽

10.1021/acs.analchem.9b02699 ◽

2019 ◽

Vol 91 (22) ◽

pp. 14314-14322 ◽

Cited By ~ 4

Author(s):

Michael Tatzel ◽

Jochen Vogl ◽

Martin Rosner ◽

Michael J. Henehan ◽

Thomas Tütken

Keyword(s):

Isotope Fractionation ◽

Icp Ms

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Comment on “Origin of water in the Badain Jaran Desert, China: new insight from isotopes” by Wu et al. (2017)

Hydrology and Earth System Sciences ◽

10.5194/hess-22-4449-2018 ◽

2018 ◽

Vol 22 (8) ◽

pp. 4449-4454 ◽

Cited By ~ 3

Author(s):

Lucheng Zhan ◽

Jiansheng Chen ◽

Ling Li ◽

David A. Barry

Keyword(s):

Lake Water ◽

Meteoric Water ◽

Isotope Composition ◽

Qilian Mountains ◽

Precipitation Rate ◽

Badain Jaran Desert ◽

Isotopic Evidence ◽

Isotope Data ◽

Local Areas ◽

The Qilian Mountains

Abstract. Precipitation isotope data were used to determine the origin of groundwater in the Badain Jaran Desert (BJD) in the study of Wu et al. (2017). Both precipitation and its isotope composition vary seasonally, so arithmetic averages of precipitation isotope values poorly represent the isotope composition of meteoric water. Their finding that the BJD groundwater is recharged by modern meteoric water from local areas including the southeastern adjacent mountains was based on arithmetic averaging. However, this conclusion is not supported by the corrected mean precipitation isotope values, which are weighted by the precipitation rate. Indeed, the available isotopic evidence shows that modern precipitation on the Qilian Mountains is more likely to be the main source of the groundwater and lake water in the BJD, as found by Chen et al. (2004).

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Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-6867-2015 ◽

2015 ◽

Vol 15 (12) ◽

pp. 6867-6877 ◽

Cited By ~ 6

Author(s):

S. J. Allin ◽

J. C. Laube ◽

E. Witrant ◽

J. Kaiser ◽

E. McKenna ◽

...

Keyword(s):

Isotope Fractionation ◽

Isotope Composition ◽

Stratospheric Ozone ◽

Standard Uncertainty ◽

Gas Chromatography Mass Spectrometry ◽

Sources And Sinks ◽

Chlorine Isotope ◽

Tropospheric Measurements ◽

Single Detector

Abstract. The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (&varepsilon;app) for mid- and high-latitude stratospheric samples are respectively −2.4 (0.5) and −2.3 (0.4) ‰ for CFC-11, −12.2 (1.6) and −6.8 (0.8) ‰ for CFC-12 and −3.5 (1.5) and −3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of the standard uncertainty expressed in per mil. Assuming a constant isotope composition of emissions, we calculate the expected trends in the tropospheric isotope signature of these gases based on their stratospheric 37Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ (37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978–2010) and tropospheric firn air samples from Greenland (North Greenland Eemian Ice Drilling (NEEM) site) and Antarctica (Fletcher Promontory site). From 1970 to the present day, projected trends agree with tropospheric measurements, suggesting that within analytical uncertainties, a constant average emission isotope delta (δ) is a compatible scenario. The measurement uncertainty is too high to determine whether the average emission isotope δ has been affected by changes in CFC manufacturing processes or not. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes (approximately 200 mL), using a single-detector gas chromatography–mass spectrometry (GC–MS) system.

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Geothermometry of Northern Tien Shan Thermal Waters (Issik-Kul Lake Basin)

10.46427/gold2020.371 ◽

2020 ◽

Author(s):

George Chelnokov ◽

Vasily Lavrushin ◽

Ivan Bragin ◽

Abdulaziz Abdullaev ◽

Natalia Kharitonova

Keyword(s):

Tien Shan ◽

Thermal Waters ◽

Lake Basin ◽

Northern Tien Shan

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