Peridotitic mantle section beneath V.Grib kimberlite pipe (Arkhangelsk region, Russia): mineralogical composition, P-T conditions, metasomatism

Ratio of structural impurity distribution in diamond crystals and kimberlite pipe diamond potentiak (case study of Arkhangelsk region and Yakutia)

Ores and metals ◽

10.47765/0869-5997-2021-10023 ◽

2021 ◽

pp. 114-130

Author(s):

Galina Khachatryan ◽

Nataliya Anashkina

Keyword(s):

Kimberlite Pipe ◽

Impurity Distribution ◽

Low Grade ◽

Arkhangelsk Region ◽

Negative Factor ◽

Diamond Crystals ◽

Thermodynamic Conditions ◽

Structural Impurity ◽

Diamond Potential

IR spectroscopy was used to compare diamonds from 12 pipes, Arkhangelsk region. Based on positive correlation between average N and H values in diamonds from various deposits, it was found that crystals from low-grade diamond pipes are relatively enriched in hydrogen compared with diamonds from Lomonosov and Grib deposits. In terms of structural impurity distribution, Arkhangelsk deposit diamonds differ from Yakutian diamonds; it could be due to various composition of compared diamonds’ source matter and thermodynamic conditions of their growth. It is shown that hydrogen is a negative factor of diamond potential in both Yakutian and Arkhangelsk diamonds. This can partly be explained by impuri-ty blocking effect on diamond crystal growth.

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Peridotite and pyroxenite xenoliths from the Muskox kimberlite, northern Slave craton, Canada

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2015-0083 ◽

2016 ◽

Vol 53 (1) ◽

pp. 41-58 ◽

Cited By ~ 4

Author(s):

David E. Newton ◽

Maya G. Kopylova ◽

Jennifer Burgess ◽

Pamela Strand

Keyword(s):

Partial Melting ◽

Bulk Composition ◽

Kimberlite Pipe ◽

Spinel Peridotite ◽

Small Scale ◽

Local Effects ◽

Slave Craton ◽

Shallow Zone ◽

Mantle Fluids ◽

Peridotitic Mantle

We present petrography, mineralogy, and thermobarometry for 53 mantle-derived xenoliths from the Muskox kimberlite pipe in the northern Slave craton. The xenolith suite includes 23% coarse peridotite, 9% porphyroclastic peridotite, 60% websterite, and 8% orthopyroxenite. Samples primarily comprise forsteritic olivine (Fo 89–94), enstatite (En 89–94), Cr-diopside, Cr-pyrope garnet, and chromite spinel. Coarse peridotites, porphyroclastic peridotites, and pyroxenites equilibrated at 650–1220 °C and 23–63 kbar (1 kbar = 100 MPa), 1200–1350 °C and 57–70 kbar, and 1030–1230 °C and 50–63 kbar, respectively. The Muskox xenoliths differ from xenoliths in the neighboring and contemporaneous Jericho kimberlite by their higher levels of depletion, the presence of a shallow zone of metasomatism in the spinel peridotite field, a higher proportion of pyroxenites at the base of the mantle column, higher Cr2O3 in all pyroxenite minerals, and weaker deformation in the Muskox mantle. We interpret these contrasts as representing small-scale heterogeneities in the bulk composition of the mantle, as well as the local effects of interaction between metasomatizing fluid and mantle wall rocks. We suggest that asthenosphere-derived pre-kimberlitic melts and fluids percolated less effectively through the less permeable Muskox mantle, resulting in lower degrees of hydrous weakening, strain, and fertilization of the peridotitic mantle. Fluids tended to concentrate and pool in the deep mantle, causing partial melting and formation of abundant pyroxenites.

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Metasomatic origin of garnet xenocrysts from the V. Grib kimberlite pipe, Arkhangelsk region, NW Russia

Geoscience Frontiers ◽

10.1016/j.gsf.2016.08.005 ◽

2017 ◽

Vol 8 (4) ◽

pp. 641-651 ◽

Cited By ~ 14

Author(s):

E.V. Shchukina ◽

A.M. Agashev ◽

N.P. Pokhilenko

Keyword(s):

Kimberlite Pipe ◽

Arkhangelsk Region

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Origin of coarse-granular and equigranular eclogites from V. Grib kimberlite pipe, Arkhangelsk region, NW Russia

International Kimberlite Conference Extended Abstracts: 2017 ◽

10.29173/ikc3830 ◽

2019 ◽

Keyword(s):

Kimberlite Pipe ◽

Arkhangelsk Region

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Kelyphite Rims on Garnets of Contrast Parageneses in Mantle Xenoliths from the Udachnaya-East Kimberlite Pipe (Yakutia)

Minerals ◽

10.3390/min11060615 ◽

2021 ◽

Vol 11 (6) ◽

pp. 615

Author(s):

Lyudmila Pokhilenko

Keyword(s):

Kimberlite Pipe ◽

Mantle Xenoliths ◽

High Alumina ◽

Coarse Grain ◽

New Classification ◽

Mantle Fluid ◽

Chromium Spinel ◽

Mantle Section

A new classification of kelyphitic rims on garnets from xenoliths of peridotitic and eclogitic parageneses of the mantle section under the Udachnaya-East kimberlite pipe (Yakutia) is presented. Five types of rims are identified: Rim1 develops between garnet and olivine/pyroxene (or rim2) and is composed of high-alumina pyroxenes, spinel, phlogopite; rim2, the coarse grain part of rim1, is located between rim1 and olivine/pyroxene, and mainly consists of phlogopite and less aluminous larger pyroxenes and spinel; rim3 develops between garnet and kimberlite, and presents with phlogopite and Fe-Ti spinel; rim4 sometimes presents instead of rim1/rim2 and consists of zoned high-Cr phlogopite with rare fine grains of chromium spinel; rim5, a “pocket” between garnet and rim1, is represented by microcrystalline aggregates of clinopyroxene, mica, spinel, calcite, and feldspar in different variations. Rims 1, 2, and 3 are typical for garnets of all studied parageneses. Rims 4 and 5 develop on high-Cr subcalcic garnets of the most depleted peridotites. Reactions of the formation of all types of rims are given in the article. Each type of kelyphite demonstrates a clear enrichment with a certain component: Rim1—MgO and alkalis; rim2—TiO2; rim3—FeO and TiO2; rim4—Cr2O3; and rim5—СаО, suggesting the multistage injection of different components by mantle fluid.

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Applications of SEM/EDXA in cement clinker investigation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177489 ◽

1990 ◽

Vol 48 (4) ◽

pp. 870-871

Author(s):

Arezki Tagnit-Hamou ◽

Shondeep L. Sarkar

Keyword(s):

Mineralogical Composition ◽

Physicochemical Characteristics ◽

Cement Clinker ◽

Accurate Information ◽

Phase Identification ◽

History Of ◽

Bulk Chemical ◽

Resolution Imaging ◽

Proven Method ◽

Instantaneous Chemical

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.

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