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31.
Aitkenhead Isabella Kuleshov Yuriy Watkins Andrew B. Bhardwaj Jessica Asghari Atifa 《Natural Hazards》2021,109(2):1425-1455
Natural Hazards - The Northern Murray–Darling Basin (MDB) is a key Australian agricultural region requiring efficient Agricultural Drought Management (ADM), focused on resilience. Although a... 相似文献
32.
Isotopic compositions of carbon (δ13C from −51.4 to −10.8
PDB) and oxygen (δ18O from 14.4 to 21.4
SMOW) were studied in rhodochrosite and calcite from manganese ores in the South Faizuly and Kyzyltash deposits of the southern Urals. The geological, petrographic, and isotopic data indicate that the studied carbonates are diagenetic formations. It is suggested that the main ore element (Mn) was delivered to the marine basin with hydrothermal solutions percolating in the oceanic crust. Manganese precipitated on the oceanic bottom as oxides near solution discharge zones. Manganese carbonates formed in sediments as a result of the oxidation of organic matter by manganese oxides. High biological productivity of the environment was caused by proximity to the hydrothermal vent that provided favorable biogeochemical conditions for the development of biocoenosis. Anomalously low 13C values in the South Faizuly deposit testify to the large-scale oxidation of methane in the course of manganese carbonate formation.__________Translated from Litologiya i Poleznye Iskopaemye, No. 4, 2005, pp. 416–429.Original Russian Text Copyright © 2005 by Kuleshov, Brusnitsyn. 相似文献
33.
A. A. Makhnach V. N. Kuleshov V. I. Vinogradov B. G. Pokrovsky N. S. Petrova M. I. Bujakaite S. V. Antipenko O. V. Murashko 《Lithology and Mineral Resources》2013,48(4):327-342
Peculiar features of evaporitic process at the stage of potassium accumulation are considered on the basis of carbon and oxygen isotope data on carbonate rocks and sulfur isotope data on anhydrite from the Famennian potassium-bearing subformation of the Starobin potassic salt deposit in the Pripyat trough. It was found that potassium accumulation was accompanied by the influx of continental waters and highly concentrated brines, while the formation of thick salt-free units was related to the replenishment of fresh seawater to the basin. 相似文献
34.
Lithology and Mineral Resources - The study of structural features along with carbon and oxygen isotope compositions made it possible to discriminate lithological rocks in deposits of the Karatau... 相似文献
35.
New isotope and mineral data on manganese carbonates of the Mazul deposit (Krasnoyarsk region) in combination with morphology of ore bodies suggest that the ores were formed in several stages with the involvement of meteoric solutions through infiltration and, possibly, exfiltration mechanisms. Based on the geological–geochemical data, manganese carbonates of the Mazul deposit may be ascribed to a new genetic subtype of the catagenesis (epigenesis) zone. 相似文献
36.
V. N. Kuleshov 《Lithology and Mineral Resources》2012,47(3):217-233
Study of carbonate inclusions in the Mamatwan-type oxide ores (braunite lutites) made it possible to reveal residual microbial
structures in them. Their presence in manganese ores, the type of manganese oxide mineralization, isotope signatures of manganese
carbonates, and available literature data on the geology of the Kalahari manganese field suggest that manganese ore formation
was widespread at the postsedimentary stage of transformation of the primary microbial sediment. The deposit can be referred
to the hydrothermal-metasomatic type. 相似文献
37.
The formation of manganese rocks and ores occurred during the whole geological history of the Earth. Five metallogenic epochs
(Early to Middle Proterozoic, Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, and Meso-Cenozoic) and 7 very important
phases (Early, Middle, and Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, Late Mesozoic, and Meso-Cenozoic)
can be distinguished. The phases of manganese ore genesis at many stratigraphic levels are closely related to the global climatic
and tectonic reconstructions (the breakup of the continent of Gondwana and periods of glaciations and aridization) and biotic
events (mass extinction of organisms). Based on carbon isotopic composition in manganese carbonates, participation of oxidized
organic carbon is established. 相似文献
38.
The isotopic composition of carbon and oxygen was studied in carbonate concentrations with different compositions (calcite, dolomite, and siderite) from Jurassic, Cretaceous, and Tertiary terrigenous deposits of the Northern Caucasus. Wide variations in the isotopic composition (from 41.4 to 18.1 for 13C and from 11.7 to 33.5 for 18O) point to different formation conditions in the early diagenesis zone and the later catagenesis zone. 相似文献
39.
V. N. Kuleshov 《Lithology and Mineral Resources》2001,36(6):537-554
Principal regular patterns in the formation of carbon and oxygen isotopic compositions in carbon dioxide–water systems are considered in application to a wide range of postdiagenetic carbonates. Carbonates produced under conditions of freshwater infiltration, elision catagenesis, and brine-induced catagenesis are characterized in terms of isotope studies. 相似文献
40.
The results of isotope-geochemical studies of carbonates of different mineral types from manganese and host rocks of the Famennian manganiferous formation of Pai-Khoi are reported. Kutnahorite ores are characterized by δ13C values from–6.6 to 1.3‰ and δ18O from 20.0 to 27.4‰. Rhodonite–rhodochrosite rocks of the Silovayakha ore occurrence have δ13C from–5.2 to–2.9 and δ18O from 25.4 to 24.3‰. Mineralogically similar rocks of the Nadeiyakha ore occurrence show the lighter carbon and oxygen isotopic compositions: δ13C from–16.4 to–13.1 and δ18O from 24.8 to 22.5‰. Similar isotopic compositions were also obtained for rhodochrosite–kutnahorite rocks of this ore occurrence: δ13C from–13.0 to–10.4‰ and δ18O from 24.6 to 21.7‰. Siderorodochrosite ores differ in the lighter oxygen and carbon isotopic compositions: δ18O from 18.7 to 17.6‰ and δ13C from–10.2 to–9.3‰, respectively. In terms of the carbon and oxygen isotopic compositions, host rocks in general correspond to marine sedimentary carbonates. Geological-mineralogical and isotope data indicate that the formation of the manganese carbonates was related to the hydrothermal ore-bearing fluids with the light isotopic composition of oxygen and carbon dissolved in CO2. The isotopic features indicate an authigenic formation of manganese carbonates under different isotopegeochemical conditions. 相似文献