scholarly journals ISOTOPIC COMPOSITION OF CARBON AND OXYGEN IN SEDIMENTATION AND EPIGENETIC CARBONATES OF THE LOWER TRANSITIONAL MEMBER OF THE VERKHNEKAMSKOE SALT DEPOSIT

2021 ◽  
Author(s):  
I.I. Сhaikovskiy ◽  
◽  
T.V Fedorov ◽  
◽  
Keyword(s):  
Isotopic Composition ◽  
Rock Salt ◽  
Columnar Structure ◽  
Salt Deposit ◽  
Plant Detritus ◽  
Calcite Veins ◽  
Melt Water ◽  
Host Rocks ◽  
Verkhnekamskoe Salt Deposit

In contrast to the carbonate-sulfate evaporites of the Syukeevskoe deposit and the salts of the Starobinskoe deposit, the formation of the salt stratum of the Verkhnekamskoe deposit is assumed to involve melt water formed between the P2 and P3 glacial events. Comparison of host rocks and newly formed mineralization made it possible to show that the process of diagenesis in carbonate-argillaceous strata alternating with rock salt was difficult. Initially, there was a decomposition of dispersed plant detritus, which is confirmed by the lightening of the isotopic composition of carbon. After the interaction of sulfate-containing sediment with desalinated waters, the anhydrite was replaced by 16O-enriched calcite. The complete lithification and stratification of clay strata led to the formation of exfoliation cavities, in which halite-calcite veins of columnar structure were formed associated with the influx of brines from neighboring salt strata enriched in 18O.

The Nd- and Sr-isotopic composition of I-type microgranitoid enclaves and their host rocks from the Swifts Creek Pluton, southeast Australia

1990 ◽  
Vol 85 (1-2) ◽  
pp. 119-134 ◽  
Author(s):  
G.W. Eberz ◽  
I.A. Nicholls ◽  
R. Maas ◽  
M.T. McCulloch ◽  
D.J. Whitford
Keyword(s):  
Isotopic Composition ◽  
Southeast Australia ◽  
Host Rocks

scholarly journals Isotopic Fractionation at the Base of Polar and Sub-Polar Glaciers

1986 ◽  
Vol 32 (112) ◽  
pp. 475-485 ◽  
Author(s):  
G.S. Boulton ◽  
U. Spring
Keyword(s):  
Isotopic Composition ◽  
Large Scale ◽  
Isotopic Fractionation ◽  
Strong Support ◽  
Sharp Change ◽  
West Antarctica ◽  
Tectonic Structures ◽  
Melt Water ◽  
Glacier Ice ◽  
Hydrological System

AbstractThe melting of ice and the subsequent production of regelation ice from the melt water in a large-scale closed system beneath sub-polar and polar glaciers produces progressive fractionation between the melt water and the regelation ice derived from it. A theory is developed which predicts the change of isotopic composition in regelation ice in a subglacial zone of freezing and in the water from which it is derived. The theory is tested against data from the Byrd Station bore hole in West Antarctica, and applied to explain features of the isotopic composition in several other glaciers where thick sequences of regelation ice have formed.The principal conclusions are:1. Basal isotopic profiles can be used to reconstruct important features of a glacier’s hydrological system.2. Isotopic profiles in basal regelation ice do not simply reflect isotopic characteristics of ancient atmospheres but also, by using the theory, some of the isotopic characteristics of the normal glacier ice which was destroyed by melting and subsequently produced regelation ice can be reconstructed. Basal regelation ice at Byrd Station reflects an original ice source isotopically colder than the overlying normal ice, and may have formed during the penultimate glacial period, equivalent to stage 6 of the oceanic record.3. The subglacially derived debris typically found in basal regelation ice gives a complex strain response to a changing pattern of stresses produced by flow over an irregular subjacent bed. Thus, complex tectonic structures in this ice produce highly variable isotopic profiles. However, its gross isotopic characteristics can still be used to reconstruct some of its history. A sharp change in isotopic values tends to occur at the upper limit of basal regelation ice, the nature of which depends on the style and thickness of tectonic disturbance.4. Isotopic profiles in basal ice can be used to distinguish normal glacier ice from regelation ice, and give strong support to the view that regelation is the major process by which debris is incorporated into the base of a glacier.

Oxygen isotopic composition of quartz veins and host rocks at the Sukhoi Log deposit, Russia

2009 ◽  
Vol 51 (6) ◽  
pp. 505-512 ◽  
Author(s):  
T. A. Ikonnikova ◽  
E. O. Dubinina ◽  
M. R. Saroyan ◽  
A. V. Chugaev
Keyword(s):  
Isotopic Composition ◽  
Oxygen Isotopic Composition ◽  
Quartz Veins ◽  
Oxygen Isotopic ◽  
Host Rocks

scholarly journals Mineral stability, brine development and rock-fluid reaction at repository-relevant temperatures (<i>T</i> < 200 °C) in the potential host rock rock salt

2021 ◽  
Vol 1 ◽  
pp. 101-102
Author(s):  
Michael Mertineit ◽  
Michael Schramm
Keyword(s):  
Melting Point ◽  
Rock Salt ◽  
Site Selection ◽  
Host Rock ◽  
Mineralogical Composition ◽  
Confining Pressure ◽  
Maximum Temperature ◽  
General Importance ◽  
Host Rocks ◽  
The Impact

Abstract. For a repository of heat generating radioactive waste, the thermal behaviour of the host rock and the impact of temperature increase on rock properties is of general importance. In the German Site Selection Act (2017), the maximum temperature of the container surface is preliminarily limited to 100 ∘C but this limit might change in the future based on scientific and technological findings. Rock salt, as one of the possible host rocks, consists predominantly of halite with varying amounts of accessory minerals (e.g., Hudec and Jackson, 2007); however, some lithological units within a salt deposit, e.g. potash seams, show a different mineralogical composition with high amounts of potash minerals. Most of them are not very stable regarding temperature resistance and stress, contain water in the crystal lattice, and therefore react sensitively to changes in the environment. The melting point of most evaporated minerals is higher than the expected temperatures in a repository but dehydration and partial melting might occur at relevant temperatures, depending on the confining pressure. For example, the temperature of dehydration of carnallite is ca. 80 ∘C at 0.1 MPa confining pressure but increases to ca. 145 ∘C at 10 MPa confining pressure (Kern and Franke, 1986). The melting point of carnallite increases from ca. 145∘C/8MPa to ca. 167∘C/24MPa, which corresponds to a depth of ca. 1000 m. Depending on the mineral paragenesis and composition of saline solutions, different minerals develop with increasing temperature. For instance, a salt rock with an initial composition of kieserite + kainite + carnallite + solution R (25 ∘C) reacts solely to kieserite and solution R, when the temperature increases to 78 ∘C. A rock with a composition of kieserite + carnallite + bischofite + solution Z (25 ∘C) reacts to kieserite + carnallite from 25 to 50 ∘C, from 50 to 73 ∘C only kieserite is stable, and at temperatures >73 ∘C kieserite and bischofite develop (Usdowski and Dietzel, 1998). For the construction of an underground repository, the mineralogical composition of the host rocks and fluids have to be evaluated carefully and play an important role for the site selection and design of the underground facility.

scholarly journals Climatic Change in a High-Altitude Alpine Area Suggested by the Isotopic Composition Of Cold Basal Glacier Ice

1990 ◽  
Vol 14 ◽  
pp. 168-171 ◽  
Author(s):  
R. Lorrain ◽  
W. Haeberli
Keyword(s):  
Isotopic Composition ◽  
High Altitude ◽  
Temperature Effect ◽  
Climatic Change ◽  
Swiss Alps ◽  
Value Differences ◽  
Water Percolation ◽  
Melt Water ◽  
Glacier Ice ◽  
First Time

For the first time, a cold ice cover of a summit in the central Swiss Alps has been sampled from the surface to the bed for determining its isotopic composition in δD and δ18O. Results of the analyses show a striking decrease of δ-values with depth. The δ-value differences are greater than those explicable by a direct temperature effect, but a substantial increase in melt water percolation through the firn since the formation of the deepest ice layer may explain the situation of this high-altitude ice.

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