scholarly journals Ancient acid rains in Ediacaran – an alternative story for sulfate sedimentation

2021 ◽  
Author(s):  
Michail Shaldybin
Keyword(s):  
Sulfuric Acid ◽  
Chemical Reactions ◽  
Volcanic Activity ◽  
Siberian Craton ◽  
Point Of View ◽  
East Siberia ◽  
Earth’S Atmosphere ◽  
Early Stages ◽  
Terrigenous Rocks ◽  
Unstable Phase

Abstract Vast deposits of anhydrite and magnesite widely distributed in Ediacaran strata of East Siberia near the Riphean unconformity. Anhydrite-rich rocks are not look like of evaporitic origin find mostly nodules and the layers of chicken-wire structure otherwise disseminated as tiny sulfate forms amongst the terrigenous rocks. Here we propose an alternative point of view for anhydrite appearance – the enrichment of Sulphur because of the slashing increase the content of sulfur in the Ediacaran atmosphere due to high volcanic activity. It is suggested that the ancient Earth's atmosphere could have also been influenced by powerful sulfuric acid rains that eroded the Precambrian dolomites causing their aggressive degradation. Chemical reactions with dolomite and sulfuric acid showed that in the early stages an unstable phase of bassanite occur which later stabilized as anhydrite after its heating as an analogue of aging. Aggressive acids have caused global process of dolomite karstification of the Siberian craton with appearance in Ediacaran strata in addition to the sulfate phases, including magnesite and sulphurous phases of pyrite and barite.

scholarly journals On the agency of water in volcanic eruptions; with some observations on the thickness of the Earth's crust from a geological point of view; and on the primary cause of volcanic action

1887 ◽  
Vol 41 (246-250) ◽  
pp. 117-173 ◽  
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruptions ◽  
Point Of View ◽  
Earth’S Crust ◽  
Difference Of Opinion ◽  
Established Fact ◽  
The Subject ◽  
Earth's Crust

The important part played by water in volcanic eruptions is a well recognised and established fact, but there is great difference of opinion among geologists as to whether water should be considered the primary or secondary agent, and as to the mode, time, and place of its intervention. The prevailing opinion in this country is that water is the primary cause of volcanic activity. Whichever view may be adopted, the subject is one which is so largely concerned with the laws regulating the underground circulation of water, that the consideration of the two questions must proceed pari passu .

scholarly journals Morphology and Contractility of Cardiac Myocytes in Early Stages of Streptozotocin-Induced Diabetes Mellitus in Rats

2013 ◽  
pp. 489-501 ◽  
Author(s):  
M. CAGALINEC ◽  
I. WACZULÍKOVÁ ◽  
O. ULIČNÁ ◽  
D. CHORVAT
Keyword(s):  
Ventricular Myocytes ◽  
Calcium Transient ◽  
Detection Algorithm ◽  
Heart Tissue ◽  
Left Ventricular ◽  
Contour Detection ◽  
Point Of View ◽  
Calcium Handling ◽  
Early Stages ◽  
Streptozotocin Induced Diabetes

Diabetic cardiomyopathy is the leading cause of mortality in type 1 diabetes. Thus study of cardiomyocyte morphology and function during early stages of diabetes using modern analytical methods is of critical importance. Therefore, using confocal microscopy, we determined metric parameters, volumes and contractility, with calcium transients in isolated left-ventricular myocytes at one week after induction of diabetes in rats. Myocyte volume analysis from 3D confocal scans was performed using an automated contour detection algorithm that took the actual shape of the myocytes into account. We showed a significant reduction in myocyte volume in diabetic animals. We also showed a significant reduction in length and width but not in thickness of the myocytes, which suggests disproportional reorganization of the structure of the heart tissue during short-term diabetes. From a functional point of view, we observed a significant decrease in cell shortening at a stimulation frequency of 0.5 Hz. This was accompanied by a decrease in calcium transient amplitude. Together, these data suggest that impaired calcium handling is one of the factors that contributes to the observed decrease in myocyte shortening during early stages of streptozotocin-induced diabetes in rats.

II.—The Red Zone in the Basaltic Series of the County of Antrim

1908 ◽  
Vol 5 (8) ◽  
pp. 341-344 ◽  
Author(s):  
Grenville A. J. Cole
Keyword(s):  
Volcanic Activity ◽  
Point Of View ◽  
Acid Lava ◽  
North Eastern ◽  
Basaltic Series

One of the most beautiful features at the Giants' Causeway, from an artistic as well as a geological point of view, is the broad red zone that divides the Lower from the Upper Basalts. As is well known, this zone of lithomarge, bole, and laterite is remarkably persistent in north-eastern Ireland, and represents an interval of Eocene time when volcanic activity was lessened and when the basalts ceased to appear at the surface. At the same time, however, sporadic eruptions of rhyolite occurred, and some of the cones of acid lava supplied material for an interbasaltic conglomerate of rhyolite pebbles, which was discovered several years ago by Mr. A. McHenry near Glenarm.

scholarly journals Geodynamic Emplacement Setting of Late Jurassic Dikes of the Yana–Kolyma Gold Belt, NE Folded Framing of the Siberian Craton: Geochemical, Petrologic, and U–Pb Zircon Data

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1000
Author(s):  
Valery Yu. Fridovsky ◽  
Kyunney Yu. Yakovleva ◽  
Antonina E. Vernikovskaya ◽  
Valery A. Vernikovsky ◽  
Nikolay Yu. Matushkin ◽  
...  
Keyword(s):  
Mantle Source ◽  
Siberian Craton ◽  
Late Jurassic ◽  
Igneous Rocks ◽  
Northeastern Asia ◽  
Geodynamic Model ◽  
Terrigenous Rocks ◽  
Depleted Mantle ◽  
Ocean Ridge ◽  
Ocean Islands

We present the results of geostructural, mineralogic–petrographic, geochemical, and U–Pb geochronological investigations of mafic, intermediate, and felsic igneous rocks from dikes in the Yana–Kolyma gold belt of the Verkhoyansk–Kolyma folded area (northeastern Asia). The dikes of the Vyun deposit and the Shumniy occurrence intruding Mesozoic terrigenous rocks of the Kular–Nera and Polousniy–Debin terranes were examined in detail. The dikes had diverse mineralogical and petrographic compositions including trachybasalts, andesites, trachyandesites, dacites, and granodiorites. The rocks showed significant similarities in distributions of REE, and their concentrations of most HFSEs were close to the intermediate ones between ocean islands basalts and enriched middle ocean ridge basalts. We propose that the subduction that was ongoing during the collision of the Kolyma–Omolon superterrane with Siberia led to melting in the asthenospheric wedge and in the lithosphere, which formed a mixed source for the dike systems from both an enriched and a depleted mantle source. The U–Pb SHRIMP-II dates obtained for the dikes corresponded to the Late Jurassic interval of 151–145 Ma. We present a geodynamic model for the northeastern margin of the Siberian Craton for the Tithonian age of the Late Jurassic.

Pajala Fireball

2021 ◽  
Author(s):  
Juha Vierinen ◽  
Torsten Aslaksen ◽  
Jorge Chau ◽  
Maria Gritsevich ◽  
Björn Gustavsson ◽  
...  
Keyword(s):  
Shock Waves ◽  
Chemical Reactions ◽  
Imaging System ◽  
Plasma Turbulence ◽  
Meteor Shower ◽  
Plasma Transport ◽  
Earth’S Atmosphere ◽  
Meteoric Body ◽  
Earth's Atmosphere ◽  
Made In

<p>Meteoroids entering the Earth's atmosphere are associated with a number of phenomena including ablation, ambipolar diffusion, plasma transport, chemical reactions, shock waves, and plasma turbulence. A bright daylight fireball observed on 2020-12-04 13:30 UTC with two meteor cameras located in Skibotn and Sørreisa allowed the precise entry trajectory of the fireball to be determined. The path of the entering object is approximately between Angeli Finland and Pajala Sweden. Based on the brightness and entry trajectory, it is possible to estimate the approximate mass of the object, and associate it with a meteor shower (Northern Taurids). The effects of the fireball on the atmosphere were detected with a number of radar and radio instruments within the region, including ionosondes, meteor radars, an all-sky VHF imaging system, and an infrasound sensor. These observations allow a detailed study of the atmospheric interaction of a large meteoric body with the Earth's atmosphere to be made. In this talk, we will describe the observations of this fireball and discuss preliminary findings.</p>

Harmful health effects of snus consumption

2021 ◽  
Vol 90 (4) ◽  
pp. 60-65
Author(s):  
L.F. Luchsheva ◽  
◽  
A.V. Litvinov ◽  
A.V. Nasatyuk ◽  
K.Yu. Slivko ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Social Workers ◽  
Health Effects ◽  
Oral Mucosa ◽  
Precancerous Lesions ◽  
Point Of View ◽  
Somatic Health ◽  
Early Stages

From a pharmacological point of view, snus is an addictive nicotine-containing substance that also contains carcinogenic nitrosamines. The level of nicotine in the blood of a snus user and a tobacco smoker is approximately the same. Dentists, educators, social workers, parents, as well as consumers of snus are poorly informed about the consequences of its use for health, including for the oral cavity. The article contains materials on the dangers of snus consumption on general somatic health, as well as on precancerous lesions and neoplasms of the oral cavity resulting from snus use, and ways to detect changes in the oral mucosa in the early stages of snus consumers.

Oscillations of the earth’s atmosphere with allowance for the variation of temperature with latitude

1963 ◽  
Vol 271 (1344) ◽  
pp. 44-56 ◽  
Keyword(s):  
Zonal Wind ◽  
Point Of View ◽  
Spherically Symmetric ◽  
Resonance Theory ◽  
Height Profile ◽  
Earth’S Atmosphere ◽  
Zonal Winds ◽  
Difference Form ◽  
Earth's Atmosphere ◽  
Resonant Period

The paper contains a theoretical investigation of the oscillations of the earth’s atmosphere, with allowance made for the variation of temperature with latitude, and for the existence of zonal winds. A pair of partial differential equations, giving divergence and pressure as functions of height and latitude are obtained; these are expressed infinite difference form as far as variation with respect to latitude is concerned, and subjected to a transformation. The resulting equations are found to resemble the corresponding equations of the Taylor-Pekeris theory for a spherically symmetric atmosphere, but to contain additional terms, the most important of which depends on the zonal wind rather than on temperature. The magnitudes of the additional terms are estimated using observational data published by Murgatroyd and by Batten, and their effect examined from the point of view of the resonance theory. The effect is found to be insufficient to remove the difficulty at present standing in the way of the resonance theory, namely, that an atmosphere with the observed temperature-height profile does not have a resonant period sufficiently near 12 solar hours.

Volume Averaged Equations for Mass Transport and Reaction for In-Situ Combustion

2017 ◽  
Vol 15 (5) ◽  
Author(s):  
Carlos G. Aguilar-Madera ◽  
Octavio Cazarez-Candia ◽  
Francisco J. Valdés-Parada
Keyword(s):  
Mass Transport ◽  
Chemical Reactions ◽  
Oil Recovery ◽  
Chemical Species ◽  
Volume Averaging ◽  
Point Of View ◽  
General Point ◽  
Transport Parameters ◽  
Averaged Equations

Abstract In-situ combustion (ISC) is an oil recovery technique where many phenomena can take place simultaneously such as: chemical reactions, phase change, heat transfer, mass transport, thermodynamic equilibrium, and so on. Each one of these phenomena may have important contributions over the ISC behavior at any scale of interest as lab-scale, inter-wells or reservoir-scale. In this work, a mass transport study is presented. Firstly, the appropriate phase and interface governing equations at pore-scale are set up. Later, the volume averaged equations valid at macroscale are rigorously derived using the volume averaging method (VAM). The theoretical analysis is general and applies for typical oil-water-gas-rock systems found in petroleum reservoirs, and for any number of chemical species distributed in the phases. The model also allows the existence of several heterogeneous and homogeneous chemical reactions. From this general point of view, the volume averaged equations governing species and phase mass transport at macroscale, along its closure scheme to predict the effective transport parameters, are presented. We have clearly identified the length scale constraints and assumptions that support our derivations. In future works, we shall expand the range of applicability of the model by relaxing some of these assumptions. To demonstrate the applicability of the average models, we numerically predicted the longitudinal mass dispersion of oxygen for passive and reactive mass transport problems at lab-scale. The general trends of theoretical results are in concordance with previous works.

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