scholarly journals Sr-bearing phosphates of the apatite supergroup from the alkaline rocks of the Konder pluton, Khabarovsk Krai

2021 ◽  
pp. 46-59
Author(s):  
A.S. Osipov ◽  
A.A. Antonov ◽  
N.S. Vlasenko

The paper presents a mineralogical description of Sr-bearing phosphates of the apatite supergroup found in eudialyte-aegirine-albite rocks of the Konder pluton, Khabarovsk krai. The Sr-dominant phases are associated with minerals of the lamprophyllite group and titanite, whereas the Ca-dominant phases are associated with calciocatapleite and kainosite-(Y), which are the products of the decomposition of eudialyte. The phosphates probably formed during post-magmatic alteration of host rock in a following sequence: stronadelphite > fuorostrophite > Sr-rich fuorapatite (fuorocaphite) > Na-REE-fuorapatite. Their variable chemical composition indicates decreasing Sr, Ba and F contents and increasing Ca, Na, REE and (OH) contents during crystallization. The crystallization sequence could refect a decrease in alkalinity of the mineral-forming conditions. Keywords: stronadelphite, fuorostrophite, fuorocaphite, Sr-rich fuorapatite, fuorapatite, alkaline rocks, hydrothermal alterations, Konder pluton, alkaline-ultramafc complexes.

2020 ◽  
Vol 42 (4) ◽  
pp. 3-22
Author(s):  
V.V. SHARYGIN ◽  
S.G. KRYVDIK ◽  
O.V. DUBYNA

Over recent years, new rare minerals have been discovered in the alkaline rocks of the Ukrainian Shield. Agpaitic varieties of alkaline magmatic and metasomatic rocks turned out to be especially abundant in rare minerals. Numerous findings are related to alkaline metasomatites which are considered to be fenites and apofenite albitites of the Dmytrivka quarry. It is well known primarily by the presence of various accessory (Nb, REE, and Zr) minerals, as well as silicate and oxide minerals that are rare for Ukraine. The most common albite microcline fenites of this quarry are characterized by rare-earth mineralization, whereas the concentration of REE decreases in apofenite albitites and Zr and Nb increase. New rare minerals were also found in the essentially albite rock with astrophyllite, alkaline pyroxene and amphibole of the Malatersa massif and agpaitic phonolites of the Oktyabrsky massif. In the rocks of the mentioned massifs and occurrences of alkaline rocks the most interesting are the findings of the perraultite — jinshajiangite series. They were found in three points of the Azov area and include 1) perraultite and jinshajiangite in the alkaline metasomatites of the Dmytrivka quarry; 2) only perraultite in agpaitic phonolites of the Oktyabrsky massif (Kam’yana gully); 3) jinshajiangite in a veined albite rock among the gabbro of the Malatersa massif. Baotite and minerals of the hejtmanite — bafertisite series were also found in the metasomatites of the Dmytrivka quarry. The latter belong to intermediate varieties in terms of MnO (10-17 wt.%) and FeO (10-17 wt.%) which distinguishes them from Fe-rich bafertisite from other regions. A silicate mineral with high content of Na, Zr, Mn and elevated Ti and Nb is rarely observed as small inclusions in the kupletskite grains from alkaline metasomatite of the Dmytrivka quarry. According to the chemical composition it was previously diagnosed as janhaugite. Tainiolite was found in some occurrences of alkaline metasomatites in the Azov region. In addition small aggregates of the REE-enriched epidote were found in fenites of the Kaplany village, which is probably the first finding in Ukraine. Two new Zr minerals have been found in the aegirine syenites of the Korsun-Novomyrhorod pluton: elpidite and mineral with a high content of Y2O3 (13-14 wt.%) (Y-hagatalite ?).


Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 195 ◽  
Author(s):  
Wenheng Liu ◽  
Xiaodong Liu ◽  
Jiayong Pan ◽  
Kaixing Wang ◽  
Gang Wang ◽  
...  

The Qingshanbao complex, part of the uranium metallogenic belt of the Longshou-Qilian mountains, is located in the center of the Longshou Mountain next to the Jiling complex that hosts a number of U deposits. However, little research has been conducted in this area. In order to investigate the origin and formation of mafic enclaves observed in the Qingshanbao body and the implications for magmatic-tectonic dynamics, we systematically studied the mineralogy, petrography, and geochemistry of these enclaves. Our results showed that the enclaves contain plagioclase enwrapped by early dark minerals. These enclaves also showed round quartz crystals and acicular apatite in association with the plagioclase. Electron probe analyses showed that the plagioclase in the host rocks (such as K-feldspar granite, adamellite, granodiorite, etc.) show normal zoning, while the plagioclase in the mafic enclaves has a discontinuous rim composition and shows instances of reverse zoning. Major elemental geochemistry revealed that the mafic enclaves belong to the calc-alkaline rocks that are rich in titanium, iron, aluminum, and depleted in silica, while the host rocks are calc-alkaline to alkaline rocks with enrichment in silica. On Harker diagrams, SiO2 contents are negatively correlated with all major oxides but K2O. Both the mafic enclaves and host rock are rich in large ion lithophile elements such as Rb and K, as well as elements such as La, Nd, and Sm, and relatively poor in high field strength elements such as Nb, Ta, P, Ti, and U. Element ratios of Nb/La, Rb/Sr, and Nb/Ta indicate that the mafic enclaves were formed by the mixing of mafic and felsic magma. In terms of rare earth elements, both the mafic enclaves and the host rock show right-inclined trends with similar weak to medium degrees of negative Eu anomaly and with no obvious Ce anomaly. Zircon LA-ICP-MS (Laser ablation inductively coupled plasma mass spectrometry) U-Pb concordant ages of the mafic enclaves and host rock were determined to be 431.8 5.2 Ma (MSWD (mean standard weighted deviation)= 1.5, n = 14) and 432.8 4.2 Ma (MSWD = 1.7, n = 16), respectively, consistent with that for the zircon U-Pb ages of the granite and medium-coarse grained K-feldspar granites of the Qingshanbao complex. The estimated ages coincide with the timing of the late Caledonian collision of the Alashan Block. This comprehensive analysis allowed us to conclude that the mafic enclaves in the Qingshanbao complex were formed by the mixing of crust-mantle magma with mantle-derived magma due to underplating, which caused partial melting of the ancient basement crust during the collisional orogenesis between the Alashan Block and Qilian rock mass in the early Silurian Period.


1991 ◽  
pp. 86-89
Author(s):  
V. L. Matetski ◽  
V. A. Nikolaev ◽  
V. P. Poluhin ◽  
V. V. Chernyh ◽  
A. D. Chepurnoi ◽  
...  

2016 ◽  
Vol 714 ◽  
pp. 116-121 ◽  
Author(s):  
Ester Helanova ◽  
Rostislav Drochytka ◽  
Vit Cerný

The quality of the aerated concrete strongly depends on the chemical composition of the raw materials, as well as the process of the hydrothermal reaction during autoclaving. Due to the variable chemical composition of fly ashes, it is necessary to identify the effect of each ion on the formation of the microstructure of aerated concrete. This paper examines the process of formation of tobermorite with the addition of sulphates in various percentage representation. The microstructure of aerated concrete is assessed using SEM images and the mineralogical by means of X-ray analysis.


2019 ◽  
Vol 220 ◽  
pp. 03024 ◽  
Author(s):  
Oleg Morozov ◽  
Sergey Kuznetsov ◽  
Vasiliy Konyushkin ◽  
Andrey Nakladov ◽  
Alexey Nizamitdinov ◽  
...  

The synthesis conditions and the results of spectral-kinetic studies of disordered crystals series CaF2-LaF3-PrF3 with variable chemical composition are presented. The prospects of using these crystals as active media for the visible spectral range DPSS laser pumped by InGaN (GaN) laser diodes and operating on 4f-4f transitions of Pr3+ ions are discussed.


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