


卷 57, 编号 7 (2019)
- 年: 2019
- 文章: 8
- URL: https://journals.rcsi.science/0016-7029/issue/view/9471
Article
Bioavailability and Ecotoxicity of Metals in Aquatic Systems: Critical Contamination Levels
摘要
Bioavailability and ecotoxicity of metals and their relation to geochemical conditions in aquatic environments were considered. It was shown that free ions are the most penetrative species of most metals, except for organometallic complexes of some metals, for example, mercury. We analyzed models for the assessment of the hazard of metal contamination of water environments using the results of thermodynamic calculations of free ion concentrations, the ability of biological receptors to bind them, and the toxic properties of the metals. A concept was developed on the main mechanisms of metal penetration and excretion and cytotoxicity of nonessential elements. A new method was proposed for the estimation of critical levels of polymetallic contamination of water on the basis of measurements of water complexation capacity and determination of the dose–effect relations between the integrated characteristics of the polymetallic contamination and indicators of the health of the ecosystems (in situ) from the results of investigations in the northern Kola Peninsula.



Effect of Mass-Independent Isotope Fractionation of Sulfur (Δ33S and Δ36S) during SO2 Photolysis in Experiments with a Broadband Light Source
摘要
Abstract–This paper presents the results of experimental studies of the behavior of mass-independent isotope effects of sulfur Δ33S and Δ36S during photochemical processes initiated by a broadband ultraviolet radiation. Experiments were performed in a flow photochemical reactor using a high-pressure mercury lamp, which is a source of radiation of a wide range with maximum radiation intensity in the wavelength range of 270−330 nm and weaker intensity in the range of 190−250 nm. The temperature and SO2 pressure dependences of the sulfur isotope ratios in the elemental sulfur products are revealed. Based on a comparative analysis of our isotope data with data from previous experimental studies with xenon and hydrogen lamps, it was shown that the correlation between the values of δ34S, Δ33S and Δ36S in elemental sulfur depends on the relative spectral distribution of the radiation intensity. Based on a comparison of our isotope data with data from previous experimental studies with xenon and hydrogen lamps, it was shown that the correlation between the values of δ34S, Δ33S and Δ36S in elemental sulfur depends on the relative spectral distribution of the radiation intensity. Our experiments suggest that photochemical processes in the range of 250−330 nm could play a significant role in the production of an isotope sulfur anomaly in the Archean atmosphere. The conditions in which 250− 330 nm radiation prevails over the 190−220 nm radiation are consistent with the assumption that the level of solar radiation reaching the Earth’s surface in Archean was several orders of magnitude higher in the wavelength range 200−300 nm compared with the current level of radiation in this range.



Physical and Chemical Conditions of Basaltic Magmatism at the Franz Josef Land Archipelago
摘要
Data on the mineralogy and melt inclusions in rocks of basaltic complexes of different age at the Franz Josef Land Archipelago (FJL) provide an insight into systematic changes in the composition of the plagioclase, clinopyroxene, and melt inclusions with time. The composition of the inclusions indicate that the Early Jurassic melts were dominated by plateau basaltic ones, whose concentrations of major components, trace elements, and REE were similar to those in typical tholeiites of the Siberian Platform. The Early Cretaceous melts were enriched and subalkaline. Data on the melt inclusions were used to calculate parameters of the magma-generating processes. The results demonstrate how the melts evolved from the Early Cretaceous to Early Jurassic and point to the three peaks of magmatic activity at 192.2 ± 2.8, 157.4 ± 3.5, and 131.5 ± 0.8 Ma, with the magmas derived at the following depths and temperatures: 120 km, 1430–1580°С → 60–110 km, 1390–1580°С → 50–140 km, 1350–1690°С by means of mantle melting, with the development of FJL magma sources.



Upper Jurassic-Lower Cretaceous Source-Rock Evaluation and Oil—Source Rock Correlation in the Abadan Plain, Southwest Iran
摘要
Eight oil samples from Lower Cretaceous Fahliyan reservoirs and 51 core and cutting samples from Upper Jurassic-Lower Cretaceous Garau Formation in Abadan Plain, Southern Iran, were analyzed using bulk property and molecular methods in order to identify their geochemical characteristics such as maturity and source depositional environment, as well as to correlate them to respective source rock(s). Rock-Eval pyrolysis and vitrinite reflectance measurements indicated that the Garau Formation, classified as a good-to-excellent source rock, the kerogen is mainly of Type II and the maturity is in peak oil generation. The crude oils of the Fahliyan reservoir are classified as light oil (API more than 35), non-biodegraded, saturate fraction, slight even/odd predominance, and front-end biased distribution in gas chromatogram. According to molecular and isotopic data, the oils were generated by a marine carbonate source rock which was deposited under the anoxic condition. Furthermore, all the studied samples reveal compositional similarity and hence can be assigned to one oil family, originating from a common source rock. Based on compositional similarities of biomarkers and isotope data in the studied crude oils and source rock, the Upper Jurassic-Lower Cretaceous Garau Formation can be regarded as the main source rock of the oils.



Thermodynamic Properties of Fluorapophyllite-(K) and Hydroxyapophyllite-(K)
摘要
A thermochemical study of natural apophyllite-group minerals, fluorapophyllite-(K) KCa4[Si8O20]F ⋅ 8H2O (Maharashtra, India) (I) and hydroxyapophyllite-(K) KCa4[Si8O20]OH ⋅ 8H2O (Norilsk, Russia) (II), was carried out on a high-temperature heat-flux Tian-Calvet Setaram (France) microcalorimeter using the melt solution calorimetry method. The first data on the enthalpies of formation from elements are obtained for the minerals studied: –13205 ± 13 kJ/mol (I) and –13054 ± 20 kJ/mol (II). The values of their standard entropies and Gibbs energies of formation are estimated.



Hydrogeochemistry of Urban Territories in the Southern Fore-Ural Areas
摘要
Data of field studies elucidate how the chemical composition of groundwaters is formed at urban territories in the southern Fore-Ural areas. These data were used to determine the changes in the salt composition of pore-waters in the clay rocks, their exchange–adsorption characteristics, and the distribution and accumulation of supertoxicants in the rocks and waters. The effect of the chemical composition of the waters on hazardous geological processes is estimated. It is determined that the geological environment is most strongly impacted within the depth range from the surface to 15–20 m. Dioxins and heavy metals are concentrated in the ground at the sites of industrial facilities near the surface (at depths up to 5–7 m), and their concentrations drastically decrease at depths from 5–7 to 20 m. Liquid organic contaminants and water-soluble salts penetrate through almost the whole circulation zone. The self-clarification of the aquifers and the recovery of the natural parameters takes dozens to hundreds of years, even after the contamination source is eliminated, i.e., the characteristic time of this process exceeds the lifetime of one generation of humans.



Short Communications
Genetic Linkage of Corundum Plagioclasites–Kyshtymites and Miaskites of the Ilmenogorsky–Vishnevogorsky Complex, South Urals, Russia: New Rb–Sr and Sm–Nd Isotopic, Geochemical and Mineralogical Data
摘要
Abstract–New geochemical, mineralogical, and Rb–Sr and Sm–Nd isotopic data have been obtained on corundum plagioclasites–kyshtymites from the 5th Versta deposit (South Urals, Russia). The genetic link of miaskites and kyshtymites is shown. The formation of the kyshtymites is associated with the redistribution and accumulation of aluminum, calcium, HFSE, and LIL-elements at the stage of tectonic-metamorphic deformations of the Ilmenogorsky–Vishnevogorsky alkaline complex.



High-Temperature Beryl from Vugless Granite Pegmatites of the Suprunovskoye Deposit, Irkutsk Oblast, Russia
摘要
New data were obtained on the chemical composition of beryl from the Suprunovskoye deposit (wt %): 66.10 SiO2, 0.51 Na2O, 17.99 Al2O3, 0.37 MgO, 0.03 K2O, 0.02 CaO, 0.58 FeO, and 13.70 BeO (calculated). Fluid and melt inclusions were investigated for the first time in this mineral. It was found that the beryl was formed during late stages of granite magmatism from a specific pegmatite silicate melt or a water–silicate liquid enriched in water (>7 wt %), heavy REE (La/Yb = 0.48), and lithium, and depleted in fluorine and boron at a temperature of ~700°C and a pressure of ~6 kbar.


