carbonate phase
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2022 ◽  
Author(s):  
Katarzyna Stanienda-Pilecki

Abstract The results of researches of the stable isotopes, carbon 13C and oxygen 18O, measured in Triassic limestones of Opole Silesia in Poland were presented in this article. The study was carried out to obtain data for interpretation of the environment of these rocks formation. Moreover, it was possible to form the theory about diagenetic processes which influenced on the mineral composition of limestone and some of their carbonte phases. The results of study show a general differentiation of δ13C and δ18O contents in carbonate minerals. All δ18O values are less than 0 ‰. It indicates that the origin oxygen isotope composition could be probably reset by diagenesis. The crystallization temperatures of low-Mg calcite and high-Mg, calculated on the basis of δ18O values are greater than 25 oC. They are higher than typical for sea basin and are also not be related to the presence of hydrothermal solutions. The increased temperatures of calcites crystallization are related to diagenetic processes that took place after the deposition and burial of carbonate material. The preservation of high-Mg calcite, an ustable carbonate phase, which is usually trasformed into low-Mg calcite during diagenesis, is probably connected with the increased salinity of the sea basin in which studied limestones were formed.


Petrology ◽  
2021 ◽  
Vol 29 (6) ◽  
pp. 614-626
Author(s):  
V. B. Polyakov ◽  
S. N. Shilobreeva

Abstract Carbon contents and isotopic compositions were compared in the basalt groundmass of the oceanic crust of different age in the zone of the East Pacific Rise. In samples the basalt groundmass of the ancient oceanic crust (~270 Ma, ODP Site 801C) in which a carbonate phase was found, the isotopic composition of the oxidized carbon (δ13C = ±1.5‰) indicates that this carbon was formed by the precipitation of seawater dissolved inorganic carbon (DIC). In the samples in which no carbonate phase was identified, the low concentration (<0.1 wt % CO2) of oxidized dispersed carbon and its isotopic composition (δ13C < –7‰) are in the range of values typical of carbon dissolved in basalt glasses without crystallinity. This makes it possible to relate the oxidized dispersed carbon to residual carbon dissolved in the magmatic melt after CO2 degassing. The precipitation of DIC results in a positive correlation between the concentration of total carbon and its δ13C values, along with the formation of a carbonate phase. The application of this criterion to basalt groundmass samples of the young crust (~15 Ma, ODP Site 1256D) showed that oxidized dispersed carbon in the young oceanic crust groundmass was not formed by the precipitation of DIC, contradicting the generally accepted paradigm. Constant concentration and δ13C values of the reduced dispersed carbon in the basalt groundmass of the young and ancient oceanic crusts, including lithological zones where microbial activity has not been recorded, indicate that the most probable model is high-temperature abiogenic generation of reduced dispersed carbon near the ridge axis. The Fischer–Tropsch synthesis and/or Bell–Boudouard reaction provide a possible basis for the abiogenic model. The Bell–Boudouard reaction 2CO = C + CO2 leads to the formation of an adsorbed layer of elemental carbon on the fresh surfaces of minerals during background alteration of the oceanic basalt crust. The CO2–CO gas-phase equilibrium maintains the necessary depletion of the newly formed elemental carbon in the 13C isotope to δ13C < –20‰. Abiogenic models for the origin of the isotopically light reduced dispersed carbon in the basalt groundmass do not assume the presence of carbon depleted in the heavy 13C isotope in the magmatic melt.


Author(s):  
Marek Tulej ◽  
Rustam Lukmanov ◽  
Valentine Grimaudo ◽  
Andreas Riedo ◽  
Coenrad de Koning ◽  
...  

Depth profiling and atomic intensity correlation studies on mineralogical inclusion embedded in calcium carbonate phase using a miniature laser mass spectrometer are presented. The method allows the determination of complex mineralogical phases.


2019 ◽  
Vol 255 ◽  
pp. 126572 ◽  
Author(s):  
Neda Radovanovic ◽  
Ivana Malagurski ◽  
Steva Levic ◽  
Aleksandra Nesic ◽  
Gustavo Cabrera-Barjas ◽  
...  

2019 ◽  
Author(s):  
Ivana Brekalo ◽  
Wenbing Yuan ◽  
Cristina Mottillo ◽  
Yuneng Lu ◽  
Yuancheng Zhang ◽  
...  

We demonstrate a method for real-time monitoring of mechanochemical synthesis of metal-organic frameworks, by measuring changes in pressure of gas produced in the reaction. Using this manometric method to monitor the mechanosynthesis of the zeolitic imidazolate framework ZIF-8 from basic zinc carbonate reveals an intriguing feedback mechanism in which the initially formed ZIF-8 reacts with the CO<sub>2</sub> byproduct to produce a complex metal carbonate phase, the structure of which is determined from powder X-ray diffraction data. Formation of the carbonate phase may be prevented by using excess ligand, leading to quantitative formation of ZIF-8. This reaction was performed on a 90 g scale, with the excess ligand removed by sublimation.


2019 ◽  
Author(s):  
Ivana Brekalo ◽  
Wenbing Yuan ◽  
Cristina Mottillo ◽  
Yuneng Lu ◽  
Yuancheng Zhang ◽  
...  

We demonstrate a method for real-time monitoring of mechanochemical synthesis of metal-organic frameworks, by measuring changes in pressure of gas produced in the reaction. Using this manometric method to monitor the mechanosynthesis of the zeolitic imidazolate framework ZIF-8 from basic zinc carbonate reveals an intriguing feedback mechanism in which the initially formed ZIF-8 reacts with the CO<sub>2</sub> byproduct to produce a complex metal carbonate phase, the structure of which is determined from powder X-ray diffraction data. Formation of the carbonate phase may be prevented by using excess ligand, leading to quantitative formation of ZIF-8. This reaction was performed on a 90 g scale, with the excess ligand removed by sublimation.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
David Santamaria-Perez ◽  
Javier Ruiz-Fuertes ◽  
Miriam Peña-Alvarez ◽  
Raquel Chulia-Jordan ◽  
Tomas Marqueño ◽  
...  

2019 ◽  
Vol 212 ◽  
pp. 723-727 ◽  
Author(s):  
Wen Xing ◽  
Zuoan Li ◽  
Thijs Peters ◽  
Marie-Laure Fontaine ◽  
Michael McCann ◽  
...  

2018 ◽  
Vol 267 ◽  
pp. 63-67
Author(s):  
Kang-Yeong Kim ◽  
Jin-Su Kwak ◽  
Kyung-Ryul Oh ◽  
Gulbahar Atila ◽  
Young-Uk Kwon

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