Composition and origin of kelyphitic rims around garnets in fresh sheared lherzolite from the Udachnaya-East kimberlite pipe, the Siberian Craton

Author(s):  
Konstantin Solovev ◽  
Igor Sharygin ◽  
Alexander Golovin

<p>A zoned reaction rim (kelyphite) around garnet of xenolith of fresh sheared lherzolite from the Udachnaya-East kimberlite pipe, Russia, has been investigated. The aim of the study is a detailed characterization of bulk major and trace element compositions of the kelyphite zones, kelyphite-forming minerals and theirs relationships with each other and with rock-forming minerals of the lherzolite. <br>There are three point of possible origin of the kelyphite: 1) a solid-solid reaction (between garnets and rock-forming minerals) during transporting to the surface and modifying by a kimberlite melt (introduction of Na, K, Ca and H<sub>2</sub>O into the kelyphite) after reaction, 2) a reaction between garnets and a kimberlite melt, 3) mantle metasomatism.<br>Scanning electron microscopy coupled with energy dispersive spectrometry was used for phase determination and chemical analyses. Chemical composition of large grains (>6 μm) was also examined with wave-length-dispersive spectrometry on electron probe micro-analyzer. Raman spectroscopy was used for phase verification. Bulk trace element composition of reaction rim was studied by laser ablation‐inductively coupled plasma‐mass spectrometry.<br>Garnet forms rounded grains up to 4 mm in size, which are surrounded by the kelyphitic rim. The kelyphite has a concentric structure forming three distinct textural and chemical zones, which are extremely fine-grained aggregates of Cr- and Al-rich orthopyroxene, spinel with a wide range of Cr#, Cr and Al-rich clinopyroxene, amphibole, phlogopite, sodalite and olivine. Veinlets, which traverse the reaction rim and the garnet, are composed of the kelyphite-like mineral aggregate.<br>The kelyphite formation took place after the lherzolite was entrapped by the kimberlite magma during ascent and emplacement. Orthopyroxene, clinopyroxene and spinel were primarily formed (hereafter the first association). Known limits of pressure-temperature stability of sodalite, phlogopite and amphibole suggest their low-pressure crystallization in the kelyphite (hereafter the second association). The kimberlite melt participated in the formation of both the first mineral association and the second mineral association of the kelyphite. Olivine is believed to be result from a reaction between the kimberlite melt and the kelyphite after forming of the first association but before forming of the second association. On the basis of bulk chemical composition for each zone of the kelyphite and chemical composition of the precursor garnet, a material transfer into the kelyphite during the formation was quantitatively evaluated. Introduction of Mg, Fe, Ti and Ca in the kelyphite occured before formation of the second mineral association and introduction of Na, K, Ca, Cl, F and H<sub>2</sub>O due to formation of the second mineral association. Therefore, we can expect that the kimberlite melt was a diffusion agent during formation of the first mineral association (the garnet and rock-forming minerals are considered as reactants) and was a reactant during formation of the second mineral association.<br>This study was supported by the Russian Science Foundation (grant No 18-77-10062).</p>

2008 ◽  
Vol 72 (2) ◽  
pp. 593-605 ◽  
Author(s):  
N. M. Halden ◽  
L. A. Friedrich

AbstractOtoliths, the earbones of teleost (bony) fish, are constructed from alternating layers of aragonite and protein. Laser ablation inductively coupled plasma mass spectrometry and proton-induced X-ray emission are used to obtain spatially well-resolved trace element line-scans that show trace-element concentrations are correlated with the annular structure. Zoned Sr and Zn signatures are common whereas other elements such as Cu, Pb, Li and Cs can be related to the proximity of mineral deposits. Aragonite in otoliths can incorporate a wide range of trace elements at the low-ppm level including alkali- and alkaline-earth elements and base metals; Se has also been detected in proximity to coal mines. These trace elements, in combination with the annular structures, are an important archive for recording information on environments occupied by fish, environmental change and exposure to pollutants.


2006 ◽  
Vol 10 ◽  
pp. 25-28 ◽  
Author(s):  
Dirk Frei ◽  
Julie A. Hollis ◽  
Axel Gerdes ◽  
Dan Harlov ◽  
Christine Karlsson ◽  
...  

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed in 1985 and the first commercial laser ablation systems were introduced in the mid 1990s. Since then, LA-ICP-MS has become an important analytical tool in the earth sciences. Initially, the main interest for geologists was in its ability to quantitatively determine the contents of a wide range of elements in many minerals at very low concentrations (a few ppm and below) with relatively high spatial resolution (spot diameters of typically 30–100 μm). The potential of LA-ICP-MS for rapid in situ U–Th–Pb geochronology was already realised in the early to mid 1990s. However, the full potential of LA-ICP-MS as the low-cost alternative to ion-microprobe techniques for highly precise and accurate in situ U–Th–Pb age dating was not realised until the relatively recent advances in laser technologies and the introduction of magnetic sectorfield ICP-MS (SF-ICPMS) instruments. In March 2005, the Geological Survey of Denmark and Greenland (GEUS) commissioned a new laser ablation magnetic sectorfield inductively coupled plasma mass spectrometry (LA-SF-ICP-MS) facility employing a ThermoFinnigan Element2 high resolution magnetic sectorfield ICP-MS and a Merchantek New Wave 213 nm UV laser ablation system. The new GEUS LA-SF-ICP-MS facility is widely used on Survey research projects in Denmark and Greenland, as well as in collaborative research and contract projects conducted with partners from academia and industry worldwide. Here, we present examples from some of the these ongoing studies that highlight the application of the new facility for advanced geochronological and trace element in situ microanalysis of geomaterials. The application of LASF-ICP-MS based in situ zircon geochronology to regional studies addressing the Archaean geology of southern West Greenland is presented by Hollis et al. (2006, this volume).


2020 ◽  
Author(s):  
Aleksandr Savelev ◽  
Andrei Khudoley ◽  
Sergey Malyshev

<p>Meso-Neoproterozoic dolerite sills and dykes of the south-east margin of the Siberian Craton are commonly known as linked to the Sette-Daban LIP-related event (Ernst, 2014). They are localized in the Maya-Kyllakh zone which represent moderately deformed sedimentary cover of the craton. The mafic intrusions are numerous and variable in size, but the best studied are large sills up to 200 m thick. Smaller intrusions are identified to be related to the same magmatic event according to their appearance and structural position.</p><p>There are several U-Pb and Sm-Nd isochron isotopic dates for the rocks of the Ulakhanbam complex, giving a range of values from 930 to 1000 Ma. Although there is an overlap of several dates within error, sills become younger westward from 974-1005 Ma in the east part of the study area to 932-946 Ma in its west part. Due to wide range of ages they likely represent at least 2 different magmatic events, although long-term event is possible as well. To resolve this issue, new accurate dates are needed.</p><p>Chemical composition of mafic intrusions is not uniform also varying from east to west. The average Y, Zr, Nb, La, Ce, and Nd concentrations in the intrusions from the east part of the study area are approximately two times higher than in the western ones. The separation into two groups is also observed in triple discriminatory diagrams according to Sm, Ti, V, and Sc. However, εNd(T) values vary from 2.3 to 7.5 without clear correlation with chemical composition. Thus, the revealed patterns basically support interpretation with occurrence of two stages of magmatic activity, the first of which is characterized by enrichment of REEs and other elements.</p><p>The studies were supported by the Russian Science Foundation grant No. 19-77-10048.</p>


Author(s):  
N. S. Azarova ◽  
A. V. Bovkun ◽  
V. K. Garanin ◽  
D. A. Varlamov ◽  
H. L. Hong

The mineralogical and petrogeochemical features of the Neoproterozoic kimberlite rocks of the Lahtojoki and Niilonsuo pipes of the Kaavi cluster (Kaavi-Kuopio, Finland) have been studied, differences in their petrogeochemical composition, quantitative and chemical composition of oxide minerals of deep (mantle) and kimberlite genesis have been revealed. The kimberlites of the pipes are moderately titanic, but the TiO2 content in the kimberlites of Niilonsuo is higher (2.11 wt.%) than in the kimberlites from the breccia of the Lahtojoki pipe (1.07 wt.%). The kimberlites of the Niilonsuo pipe also differ in higher concentrations of Fe2 O3 , Ca, P, K, Rb, V, Nb, Ba, Th, U, Ta and REE. In the Lahtojoki kimberlite breccias the main TiO2 concentrator mineral is magnesian ilmenite (13,3—15,2 wt.% MgO; 0,5—4,4 wt.% Cr2 O3 ), (macrocrysts up to 4 mm); the fine-grained matrix of rocks contains small grains of rutile, chromespinelides, Mn-ilmenite and sometimes titanomagnetite. Macrocrystals of magnesian ilmenite have been not found in the kimberlites of the Niilonsuo pipe, perovskite acts as the main mineral of titanium, and chromespinelids and titanomagnetite are less common. Long-term crystallization of relatively large (up to 200 μm) perovskite grains proceeded according to estimates using an Nb-Fe-perovskite oxybarometer under a wide range of oxygen fugacity (fо2 ) of the kimberlite melt (NNO from -3,8 to 5,1). Chromespinelids from the groundmass of kimberlite pipe rocks differ in composition, but have the same specific zonality — enrichment of Al and Mg in the edge zones of crystals, which is possibly due to the dissolution of phlogopite phenocrysts in the rising kimberlite melt. In addition to oxide minerals, djerfisherite is widely distributed in the groundmass of kimberlites of the Niilonsuo pipe, the composition of which for the rocks of the body has been described for the first time. The combination of features of oxide mineralization indicates unfavorable conditions for the preservation of diamonds during their transportation by kimberlite melt.


2020 ◽  
Vol 16 ◽  
Author(s):  
Diogo L. R. Novo ◽  
Priscila T. Scaglioni ◽  
Rodrigo M. Pereira ◽  
Filipe S. Rondan ◽  
Gilberto S. Coelho Junior ◽  
...  

Background: Conventional analytical methods for phosphorus and sulfur determination in several matrices present normally analytical challenges regarding inaccuracy, detectability and waste generation. Objective: The main objective is proposing a green and feasible analytical method for phosphorus and sulfur determination in animal feed. Methods: Synergic effect between microwave and ultraviolet radiations during sample preparation was evaluated for the first time for the animal feed digestion associated with further phosphorus and sulfur determination by ion chromatography with conductivity detection. Dissolved carbon and residual acidity in final digests were used for the proposed method assessment. Phosphorus and sulfur values were compared with those obtained using conventional microwave-assisted wet digestion in closed vessels associated with inductively coupled plasma optical emission spectrometry and with those obtained using Association of Official Analytical Chemists International official method. Recovery tests and certified reference material analysis were performed. Animal feeds were analyzed using the proposed method. Results: Sample masses of 500 mg were efficiently digested using only 2 mol L -1 HNO3. The results obtained by the proposed method was not differing significantly (p > 0.05) from those obtained by the conventional and official methods. Suitable recoveries (from 94 to 99%), agreement with certified values (101 and 104%) and relative standard deviations (< 8%) were achieved. Phosphorus and sulfur content in commercial products varied in a wide range (P: 5,873 to 28,387 mg kg-1 and S: 2,165 to 4,501 mg kg-1 ). Conclusion: The proposed method is a green, safe, accurate, precise and sensitive alternative for animal feed quality control.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Yan ◽  
Chun-lian Wang ◽  
Steffen Mischke ◽  
Jiu-yi Wang ◽  
Li-jian Shen ◽  
...  

AbstractMajor, trace and rare earth element (REE) geochemistry of the late Cretaceous lower Zhoutian Formation from the Jitai Basin of Southeast China were measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis to infer the provenance of the sediments and to reconstruct the palaeoenvironment and palaeoclimate. The wide range of Sr/Cu ratios point to a fluctuating palaeoclimate, and the negative correlation between the FeO/MnO and Al2O3/MgO ratios and the Sr/Cu ratio indicates that the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin can be divided into two parts. The lower part experienced two cooling periods, whilst the upper part was dominated by warm-humid climate. Mostly corresponding trends of the B/Ga, Sr/Ba and Sr/Cu ratios show that the salinity changed consistently with the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin. During the lower part, the salinity changed from salt water to fresh/brackish water. In the upper part, water was mainly fresh/brackish, and there were many changes from fresh/brackish water to salt water. The relatively stable Ni/Co, V/Cr, V/(V + Ni) and Ce/Ce* data indicate a long period of oxic conditions. The La-Th-Sc, Th-Sc-Zr/10 and La/Th-Hf data of the silt- and sandstones of the lower Zhoutian Formation show that its provenance was mainly a mixture of felsic upper crust sediments and older sedimentary rocks.


Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 89
Author(s):  
Jongwon Lee ◽  
Kilsun Roh ◽  
Sung-Kyu Lim ◽  
Youngsu Kim

This is the first demonstration of sidewall slope control of InP via holes with an etch depth of more than 10 μm for 3D integration. The process for the InP via holes utilizes a common SiO2 layer as an InP etch mask and conventional inductively coupled plasma (ICP) etcher operated at room temperature and simple gas mixtures of Cl2/Ar for InP dry etch. Sidewall slope of InP via holes is controlled within the range of 80 to 90 degrees by changing the ICP power in the ICP etcher and adopting a dry-etched SiO2 layer with a sidewall slope of 70 degrees. Furthermore, the sidewall slope control of the InP via holes in a wide range of 36 to 69 degrees is possible by changing the RF power in the etcher and introducing a wet-etched SiO2 layer with a small sidewall slope of 2 degrees; this wide slope control is due to the change of InP-to-SiO2 selectivity with RF power.


2021 ◽  
Vol 9 (2) ◽  
pp. 336
Author(s):  
Laura Matarredona ◽  
Mónica Camacho ◽  
Basilio Zafrilla ◽  
Gloria Bravo-Barrales ◽  
Julia Esclapez ◽  
...  

Haloarchaea can survive and thrive under exposure to a wide range of extreme environmental factors, which represents a potential interest to biotechnology. Growth responses to different stressful conditions were examined in the haloarchaeon Haloferax mediterranei R4. It has been demonstrated that this halophilic archaeon is able to grow between 10 and 32.5% (w/v) of sea water, at 32–52 °C, although it is expected to grow in temperatures lower than 32 °C, and between 5.75 and 8.75 of pH. Moreover, it can also grow under high metal concentrations (nickel, lithium, cobalt, arsenic), which are toxic to most living beings, making it a promising candidate for future biotechnological purposes and industrial applications. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis quantified the intracellular ion concentrations of these four metals in Hfx. mediterranei, concluding that this haloarchaeon can accumulate Li+, Co2+, As5+, and Ni2+ within the cell. This paper is the first report on Hfx. mediterranei in which multiple stress conditions have been studied to explore the mechanism of stress resistance. It constitutes the most detailed study in Haloarchaea, and, as a consequence, new biotechnological and industrial applications have emerged.


Author(s):  
Radosław Rogoziński ◽  
Alina Maciejewska

AbstractVarved clay deposits from ice-dammed lakes are a particularly important and broadly applied raw material used for the production of high-quality ceramics (red bricks, roof tiles, etc.), but the mineralogy and geochemistry of these sediments are not fully understood. The aim of the present study was to determine the chemical and mineralogical composition of ice-dammed lake sediments of the Lębork deposit. Major-element analysis of the compositions of selected samples from the ice-dammed lake clays was performed by X-ray fluorescence (XRF) and trace elements were determined by inductively coupled plasma-mass spectrometry. The mineralogical composition of clay samples was determined by X-ray diffraction (XRD). Analyses of the chemical composition of the ice-dammed lake clays of the Lębork deposit showed that the dominant component was SiO2 with a mean content of 56.13 wt.%; the second most abundant component was Al2O3, with a mean content for the entire deposit of 11.61 wt.%. Analysis by ICP-MS indicated the presence of rare earth elements (REE), e.g. cerium, neodymium, lanthanum, and praseodymium; their mean contents are: 56.9, 27.0, 26.3, and 7.3 ppm, respectively. Mineralogical analysis of the varved clays identified quartz, muscovite, calcite, and clay minerals – illite, kaolinite, and montmorillonite. The material filling the Lębork basin is characterized by small lateral and vertical variability in chemical composition. The results of the present study may be of considerable importance in determining the parent igneous, metamorphic, and sedimentary rocks, the weathering products of which supplied material to the ice-dammed lake, as well as in determining the mechanisms and character of the sedimentation process itself.


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