Identification of anhydrous CaCl2 and KCaCl3 in natural inclusions by Raman spectroscopy
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https://www.sciencedirect.com/science/article/pii/S0009254118303486https://elib.sfu-kras.ru/handle/2311/111430
Автор:
Svetlana, Grishina
Peter, Koděra
Lucas M. Uriarte
Jean, Dubessy
Aleksandr, Oreshonkov
Sergey, Goryainov
František, Šimko
Igor, Yakovlev
Evgenii M. Roginskii
Коллективный автор:
Инженерно-строительный институт
Кафедра проектирования зданий и экспертизы недвижимости
Дата:
2018-08Журнал:
Chemical GeologyКвартиль журнала в Scopus:
Q1Квартиль журнала в Web of Science:
Q1Библиографическое описание:
Svetlana, Grishina. Identification of anhydrous CaCl2 and KCaCl3 in natural inclusions by Raman spectroscopy [Текст] / Grishina Svetlana, Koděra Peter, Lucas M. Uriarte, Dubessy Jean, Oreshonkov Aleksandr, Goryainov Sergey, Šimko František, Yakovlev Igor, Evgenii M. Roginskii // Chemical Geology. — 2018. — Т. 493 (№ 20). — С. 532-543Аннотация:
Anhydrous chlorides - CaCl2, and KCaCl3 (chlorocalcite) were identified as mineral inclusions in halite from the
Siberian Large Igneous Province at the contact of magmatic intrusions and evaporates. Chlorocalcite was also
found as daughter mineral in polyphase hypersaline inclusions. While Raman spectra of KCaCl3 (chlorocalcite) in
natural inclusions are similar to spectra of synthetic analogue, the Raman spectra of natural CaCl2 do not correspond
to the published Raman spectra of synthetic CaCl2. Simulations of Raman spectra using ab initio densityfunctional
theory (DFT) allowed us to calculate the spectra of individual polymorphs of CaCl2 and to discriminate
anhydrous CaCl2 phases in natural inclusions and synthetic CaCl2. In the spectrum of the Pbcn polymorph
of CaCl2 twelve different peaks could be identified at 74, 95, 99, 107, 124, 158, 164, 179, 212, 236, 244,
256 cm−1 in contrast to five peaks in the spectrum of the Pnnm polymorph of CaCl2 at 115, 157, 160, 211 and
252 cm−1. Naturally occurring CaCl2 in inclusions in halite consist of Pbcn polymorph only, which probably
results from a mechanical stress on cooling from magmatic to ambient temperatures. However, the Raman
spectra of the synthetic CaCl2 corresponds to the Pnnm phase with small contributions of the Pbcn phase.
Raman spectra of synthetic KCaCl3 with main peaks at 58, 67, 90, 97, 133, 139, 147, 193 cm−1 agrees well
with the spectra of chlorocalcite in the natural inclusions. Positions of each atom in the KCaCl3 structure were
refined using the density-functional theory. There are no imaginary phonon modes for the optimized structure,
indicating that the structure of KCaCl3 is stable. Calculated Raman spectrum is in a good agreement with the
Raman spectrum of synthetic and natural KCaCl3 samples.