Composition of garnet and clinopyroxene in peridotite xenoliths from the Grib kimberlite pipe, Arkhangelsk diamond province, Russia: Evidence for mantle metasomatism associated with kimberlite melts

Lithos ◽  
2016 ◽  
Vol 262 ◽  
pp. 442-455 ◽  
Author(s):  
A.V. Kargin ◽  
L.V. Sazonova ◽  
A.A. Nosova ◽  
V.V. Tretyachenko
Keyword(s):  
Kimberlite Pipe ◽  
Mantle Metasomatism ◽  
Peridotite Xenoliths ◽  
Diamond Province

Heterogeneous lithospheric mantle metasomatism in the eastern North China Craton: He–Ar isotopes in peridotite xenoliths from Cenozoic basalts

2014 ◽  
Vol 80 ◽  
pp. 185-196 ◽  
Author(s):  
Huayun Tang ◽  
Takuya Matsumoto ◽  
Jianping Zheng ◽  
György Czuppon ◽  
Chunmei Yu ◽  
...  
Keyword(s):  
North China Craton ◽  
Lithospheric Mantle ◽  
North China ◽  
Mantle Metasomatism ◽  
Peridotite Xenoliths

scholarly journals A Plethora of Epigenetic Minerals Reveals a Multistage Metasomatic Overprint of a Mantle Orthopyroxenite from the Udachnaya Kimberlite

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 264
Author(s):  
Dmitriy I. Rezvukhin ◽  
Taisia A. Alifirova ◽  
Alexander V. Golovin ◽  
Andrey V. Korsakov
Keyword(s):  
Melt Inclusions ◽  
Kimberlite Pipe ◽  
Mantle Metasomatism ◽  
Crystal Chemical Formula ◽  
Mineral Inclusions ◽  
Reaction Zones ◽  
Geochemical Analyses ◽  
Individual Grains ◽  
Kimberlite Field ◽  
Intergranular Space

More than forty mineral species of epigenetic origin have been identified in an orthopyroxenite from the Udachnaya-East kimberlite pipe, Daldyn kimberlite field, Siberian platform. Epigenetic phases occur as: (1) Mineral inclusions in the rock-forming enstatite, (2) daughter minerals within large (up to 2 mm) crystallized melt inclusions (CMI) in the rock-forming enstatite, and (3) individual grains and intergrowths in the intergranular space of the xenolith. The studied minerals include silicates (olivine, clinopyroxene, phlogopite, tetraferriphlogopite, amphibole-supergroup minerals, serpentine-group minerals, talc), oxides (several generations of ilmenite and spinel, rutile, perovskite, rare titanates of the crichtonite, magnetoplumbite and hollandite groups), carbonates (calcite, dolomite), sulfides (pentlandite, djerfisherite, pyrrhotite), sulfate (barite), phosphates (apatite and phosphate with a suggested crystal-chemical formula Na2BaMg[PO4]2), oxyhydroxide (goethite), and hydroxyhalides (kuliginite, iowaite). The examined epigenetic minerals are interpreted to have crystallized at different time spans after the formation of the host rock. The genesis of minerals is ascribed to a series of processes metasomatically superimposed onto the orthopyroxenite, i.e., deep-seated mantle metasomatism, infiltration of a kimberlite-related melt and late post-emplacement hydrothermal alterations. The reaction of orthopyroxene with the kimberlite-related melt has led to orthopyroxene dissolution and formation of the CMI, the latter being surrounded by complex reaction zones and containing zoned olivine grains with extremely high-Mg# (up to 99) cores. This report highlights the utility of minerals present in minor volume proportions in deciphering the evolution and modification of mantle fragments sampled by kimberlitic and other deep-sourced magmas. The obtained results further imply that the whole-rock geochemical analyses of mantle-derived samples should be treated with care due to possible drastic contaminations from “hiding” minor phases of epigenetic origin.

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

2020 ◽  
Author(s):  
Konstantin Solovev ◽  
Igor Sharygin ◽  
Alexander Golovin
Keyword(s):  
Chemical Composition ◽  
Trace Element ◽  
Inductively Coupled Plasma ◽  
Wave Length ◽  
Kimberlite Pipe ◽  
Mantle Metasomatism ◽  
Material Transfer ◽  
Mineral Association ◽  
Russian Science ◽  
Wide Range

<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>

scholarly journals Mathiasite-loveringite and priderite in mantle xenoliths from the Alto Paranaíba Igneous Province, Brazil: genesis and constraints on mantle metasomatism

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Vidyã Almeida ◽  
Valdecir Janasi ◽  
Darcy Svisero ◽  
Felix Nannini
Keyword(s):  
Mantle Metasomatism ◽  
Mantle Xenoliths ◽  
Southeastern Brazil ◽  
Chemical Zoning ◽  
Ti Oxides ◽  
Peridotite Xenoliths ◽  
Mantle Enrichment ◽  
Alkaline Intrusion ◽  
Igneous Province ◽  
Mineral Assemblages

AbstractAlkali-bearing Ti oxides were identified in mantle xenoliths enclosed in kimberlite-like rocks from Limeira 1 alkaline intrusion from the Alto Paranaíba Igneous Province, southeastern Brazil. The metasomatic mineral assemblages include mathiasite-loveringite and priderite associated with clinopyroxene, phlogopite, ilmenite and rutile. Mathiasite-loveringite (55–60 wt.% TiO2; 5.2–6.7 wt.% ZrO2) occurs in peridotite xenoliths rimming chromite (∼50 wt.% Cr2O3) and subordinate ilmenite (12–13.4 wt.% MgO) in double reaction rim coronas. Priderite (Ba/(K+Ba)< 0.05) occurs in phlogopite-rich xenoliths as lamellae within Mg-ilmenite (8.4–9.8 wt.% MgO) or as intergrowths in rutile crystals that may be included in sagenitic phlogopite. Mathiasite-loveringite was formed by reaction of peridotite primary minerals with alkaline melts. The priderite was formed by reaction of peridotite minerals with ultrapotassic melts. Disequilibrium textures and chemical zoning of associated minerals suggest that the metasomatic reactions responsible for the formation of the alkali-bearing Ti oxides took place shortly prior the entrainment of the xenoliths in the host magma, and is not connected to old (Proterozoic) mantle enrichment events.

Women at the dawn of diamond discovery in Siberia or how two women discovered the Siberian diamond province

2020 ◽  
pp. SP506-2020-11
Author(s):  
Ekaterina S. Kiseeva ◽  
Rishat N. Yuzmukhametov
Keyword(s):  
Soviet Union ◽  
Russian Literature ◽  
Kimberlite Pipe ◽  
Diamond Deposit ◽  
Diamond Exploration ◽  
Significant Events ◽  
The Soviet Union ◽  
The Government ◽  
Diamond Province

AbstractExploration for diamonds in the Soviet Union started in the 1940s; however, it was not until the beginning of 1950s that the government acknowledged a strong need for locally mined diamonds. In this paper, based on publications from Russian literature, we recount a story of two female geologists, Larisa Popugaeva and Natalia Sarsadskhih.Natalia was the head of the mineralogical laboratory who implemented a new methodology to search for mineral indicators of primary diamond deposits. Larisa was a young geologist who joined Natalia's team in 1953.The work of these women led to the discovery, in 1954, of the first diamond deposit in the country – the kimberlite pipe ‘Zarnitsa’. In 1954, Natalia was unable to go into the field and, therefore, the discovery was made by Larisa. Credit for this discovery, however, was claimed by the higher officials from the Amakinskaya expedition, one of the largest diamond exploration organizations in the country. Multiple efforts to restore justice did not succeed, with Larisa only being awarded the title of the ‘Discoverer’ in 1970 and Natalia not until 1990. This paper provides a description of Larisa's and Natalia's lives up until the discovery of Zarnitsa, and a few significant events after.

Mantle xenoliths from the Komsomolskaya-magnitnaya kimberlite pipe (Upper Muna kimberlite field, Siberian Craton) Evidences of the composition of the SCLM

2020 ◽  
Author(s):  
Igor Iakovlev ◽  
Vladimir Malkovets ◽  
Anastasiya Gibsher
Keyword(s):  
Rare Earth ◽  
Lithospheric Mantle ◽  
Kimberlite Pipe ◽  
Mantle Xenoliths ◽  
Coarse Grained ◽  
Peridotite Xenoliths ◽  
Rare Earth Element Distribution ◽  
Group 2 ◽  
Kimberlite Field ◽  
Group 1

&lt;p&gt;Peridotite xenoliths from kimberlites provide important information about the composition, structure and thermal regime of the lithospheric mantle of ancient cratons. In this paper, we present the results of mineralogical studies of peridotite xenoliths from kimberlites of the Upper Muna field. The Middle Paleozoic (D3-C1) high diamondiferous kimberlite pipe Komsomolskaya-Magnitnaya was chosen as the object of research.&lt;/p&gt;&lt;p&gt;We studied a collection of 180 peridotite xenoliths of the Komsomolskaya-Magnitnaya pipe, of which 104 belong to dunite-harzburgite paragenesis, 74 to lherzolite and 4 websterites.&lt;/p&gt;&lt;p&gt;The chemical composition of basic minerals from xenoliths was determined using JEOL JXA-8100 electron microprobe. Chemical analysis of xenolith garnet compositions was also performed using the Agilent 7700cs LAM-ICPMS method.&lt;/p&gt;&lt;p&gt;Based on a study of the collection of deep xenoliths, we found that the lithospheric mantle under the Upper Muna kimberlite field is composed mainly of garnet-bearing and chromite-bearing dunites and harzburgites, as well as coarse grained garnet lherzolites.&lt;/p&gt;&lt;p&gt;The olivine Mg# varies from 88.4 to 94.12%, while the magnitude of the majority (60%) of the studied olivines does not exceed 92% and 30% of olivines have Mg#&gt; 93%. We identified 2 groups according Mg # olivine from xenoliths. Group 1 with &amp;#8220;typical&amp;#8221; mantle values Mg # 88.39-90.70mol%, it is characteristic for fertile peridotites. And group 2 with highly depleted compositions Mg # 91.20-94.12mol%. A high proportion (~ 30%) of peridotites with high magnesian olivines (Mg #&gt; 93 mol%) indicates the presence of a block of highly depleted rocks in the lithospheric mantle beneath the Upper Muna kimberilte field.&lt;/p&gt;&lt;p&gt;According to the distribution of calcium and chromium in garnets, 10 out of 35 studied garnets from xenoliths belong to diamondiferous harzburgite-dunite paragenesis. According to the distribution of rare-earth elements, we distinguish two groups of garnets. Group 1 includes garnets with typical rare earth element distribution spectra typical for fertile garnets, and group 2 garnets with S-shaped spectra that are characteristic of garnet mineral inclusions in diamonds. We noted a high proportion of garnets with S-shaped REE distribution spectra (~ 66%), as well as garnets belonging to the harzburgite-dunite paragenesis, it indicate a moderate role of metasomatic changes associated with silicate melts, as well as interaction with carbonatite melts enriched in LREE.&lt;/p&gt;&lt;p&gt;Using clinopyroxene monomineral thermobarometry, we found that the &amp;#8220;diamond&amp;#8221; window in the lithosphere mantle beneath the Upper Muna field, at the time of kimberlite magmatism (~ 360 Ma) was significant (about 95 km) and was located at a depth of 125 to 220 km.&lt;/p&gt;&lt;p&gt;The study was supported by the Russian Science Foundation (grant No. 18-17-00249).&lt;/p&gt;

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