No 1 (2019)

ARTICLES

Late Vendian kotlinian crisis on the East European Platform: lithogeochemical indicators of depositional environment

Maslov A.V., Grazhdankin D.V., Podkovyrov V.N.

Abstract

Sharp changes in the biodiversity of fossil organisms in the Upper Vendian of the East European Platform are considered as the manifestation of global crisis immediately prior to the “Cambrian Explosion.” However, they could be caused by local environmental perturbations. Variations of some lithogeochemical indicators of depositional environment (indicators of paleoclimate, exhalation activity, redox settings, and paleobioproductivity) were analyzed in order to establish the possible influence of sedimentary systems on evolutionary processes in the Late Vendian and at the boundary with the Cambrian. The applied algorithm of lithogeochemical studies revealed no significant perturbations in physical properties of the environment on a scale of sedimentary basins. The obtained data suggest that local factors did not affect the evolution of Ediacaran biota on the East European Platform and confirm the global nature of transitions between the Redkinian, Belomorian, and Kotlinian biotas.

Литология и полезные ископаемые. 2019;1(1):2-30
pages 2-30 views

Evolution of mineral formation processes in Lower Vend terrigenous rocks of Nepsko-Botuobinskaya anteclise

Postnikov A.V., Postnikova O.V., Izyurova E.S., Poshibaev V.V., Kuznetsov A.S., Izyurov A.D., Kozionov A.E.

Abstract

Principal common factors of epigenetic occurrence in Lower Vend rocks of Nepsko-Botuobinskaya anteclise are shown in the article. Evolution of mineral formation processes is stated in the change of mineral paragenesis, which were formed on stages of regional background (stadial) lithogenesis of foundering — diagenesis, early and late katagenesis; and also as a result of local superimposed lithogeneous types complex combination – cataclastic, hydrothermal, metasomatic and dynamothermal activation. Local superimposed processes could acompony the period of Permo-Triassic trap magmatism. High degree transformation of Lower Vend terrigenous rocks of Nepsko-Botuobinskaya anteclise determinates its structure, composition and physical properties specificity, which should be taken into account in process of geological exploration of different mineral deposits.

Литология и полезные ископаемые. 2019;1(1):31-43
pages 31-43 views

Thermobaric depth settings of sedimentary rock basins and their fluid dynamics: Сommunication 2. Superhigh pressures and mud volcanoes

Kholodov V.N.

Abstract

The article discusses the patterns of placement of mud volcanoes, their spatial connection with tectonic faults, anticlinal uplifts, oil and gas fields. The connection of mud volcanic activity with ultrahigh pressures arising in the clay strata of the stratisphere as a result of phase transformations of clay minerals and organic matter is argued. The role of earthquakes in the formation of fractured clays, increasing their permeability and the formation of mud crates is emphasized. On the example of the mud volcano Aligula (Turkmenistan), the processes of dilution of sandstones and clays, the formation of volcanic mud-crates are considered.

Литология и полезные ископаемые. 2019;1(1):44-59
pages 44-59 views

Reference sections of late‒middle neopleistocene friable sediments in Kamchatka: Present-day state and issue of age, and perspectives of study

Pevzner M.M., Yashina O.V., Smyshlyaeva O.I., Nechushkin R.I., Karimov T.D., Rozhdestvensky O.Y.

Abstract

Reference sections of friable sediments in central Kamchatka are studied and their present-day state is described. Previous concepts of the Middle Pleistocene age of these sediments are critically examined. Radiocarbon dates performed in the 1980s‒1990s by researchers at the Geological Institute, Russian Academy of Sciences, are revised. It is shown that some (oldest) part of dates did not pass the quality check. Results of the new (2016‒2017) radiocarbon dating agree well with the data accomplished previously and supported later by revision. Based on the combined databank with 65 determinations of different species of the buried organic material and mammal bones, the Late Pleistocene age of sediments is suggested. A new interpretation is proposed for the formation setting of some sequences in the studied sections.

Литология и полезные ископаемые. 2019;1(1):60-89
pages 60-89 views

Gossan of the Yubileynoe massive sulfide deposit (South Urals): evidence for formation on the seafloor

Novoselov K.A., Belogub E.V., Sadykov S.A., Vikentyev I.V.

Abstract

Oxidation zone of the Yubileinoe massive sulfide deposit, South Urals, is buried beneath Jurassic sediments containing coalified plant remains. Mineralogy of gossan of this deposit is marked by the abundance of siderite. The carbon isotope composition (δ13C) in siderite varies from -20.0 to -23.4‰ PDB, which is close to δ13C variation in coals from the overlying sediments (-23.5 to -26.2‰ PDB). The formation of siderite is likely related to interaction between solutions of the Triassic oxidation zone and fermentation products of the organic matter.

Литология и полезные ископаемые. 2019;1(1):90-100
pages 90-100 views

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