Prospects of search for diamondiferous kimberlites in the northeastern Siberian Platform

Sobolev, N. V.; Sobolev, Alexander V.; Томиленко, А. А.; Kuzmin, D. V.; Grakhanov, S. A.; Batanova, Valentina; Logvinova, A. M.; Бульбак, Т. А.; Kostrovitskii, S. I.; Yakovlev, D. A.; Fedorova, E.N.; Anastasenko, G. F.; Николенко, Е. И.; Толстов, А. В.; Reutskii, V. N.

doi:10.1016/j.rgg.2018.09.012

Cited by 41 publications

(15 citation statements)

References 58 publications

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“…We sampled four Jurassic pipes in the Kuoika kimberlite field (northern Siberian craton): Dianga, Vtorogodnitsa, Olivinovaya, and Obnazhennaya ( Figure 4). According to previous results [17,[49][50][51][52], the four kimberlites, which differ in the types and chemistry of mantle minerals and in diamond grade, represent the mineralogical diversity of a certain stage of kimberlite magmatism in a specific area. The Dianga kimberlite, the deepest pipe in the field, bearing diamonds, unlike the other pipes, and is the only one with its estimated PT conditions [17,49] mainly outside the diamond stability field.…”

Section: Distribution Of Olivine Types In Sampled Kimberlitesmentioning

confidence: 99%

Types of Xenogenic Olivine from Siberian Kimberlites

et al. 2020

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This work is devoted to the systematization of the composition of xenogenic olivine from kimberlites as the main mineral composing the lithospheric mantle. Based on data on the composition of olivines from xenoliths and megacrysts from kimberlites, a general division into four types is proposed: olivines of ultrahigh-temperature (HTP-1), high-temperature (HTP-2) and low-temperature (LTP) peridotites, as well as olivines of low-chromium megacryst association (MCA). The separation scheme uses the CaO content as an indicator of the formation temperature and the Mg/(Mg + Fe) ratio as an indicator of the degree of enrichment in olivines. In contrast to Al, the Ca content in olivines from cratonic peridotites is high enough to use only EPMA when applying the proposed scheme. According to this scheme the study of more than 1500 individual olivine xenocrysts from a number of kimberlite bodies of the Siberian platform was made. It revealed three characteristic distributions of olivine types: without high-temperature differences (Obnazhennaya pipe), with significant development of HTP-2 (Olivinovaya and Vtorogodnitsa pipes), and with a significant development of HTP-1 (Dianga pipe). Only the latter type of distribution is characterized by the presence of a noticeable amount of megacryst association olivines. The study of other minor elements (TiO2 and NiO) in olivines allowed us to propose a model for the formation of high-temperature olivines of two different types due to the interaction of megacryst melt of various fractionation stages on depleted rocks of the lithospheric mantle. HTP-2 olivines arose upon exposure to a fractionated melt of the late stages of crystallization, and HTP-1 olivines appeared upon exposure to unfractionated (less enriched with incompatible components) megacryst melt at higher temperatures of the initial stage of crystallization.

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Section: Distribution Of Olivine Types In Sampled Kimberlitesmentioning

confidence: 99%

Types of Xenogenic Olivine from Siberian Kimberlites

et al. 2020

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“…Kimberlite and kimberlite-related rocks of the Yakutia province, Siberia Craton, Russia are good examples of multi impulses ultramafic alkaline magmatism within one craton. Yakutian kimberlite and kimberlite-related magmas formed during four episodes: (1) Late Silurian-Early Devonian, 419-397 Ma; (2) Late Devonian-Early Carboniferous, 376-347 Ma; (3) Late Triassic, 231-215 Ma; and (4) Middle/Late Jurassic, 171-156 Ma [21][22][23][24][25][26][27][28]. This means that a period of kimberlite province development may be much more extended than previously assumed, and new age data for various kimberlite bodies (pipes, sills, or dykes) are significant to help clarify the duration of kimberlite evolution.…”

Section: Introductionmentioning

confidence: 99%

Ultramafic Alkaline Rocks of Kepino Cluster, Arkhangelsk, Russia: Different Evolution of Kimberlite Melts in Sills and Pipes

et al. 2021

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To provide new insights into the evolution of kimberlitic magmas, we have undertaken a detailed petrographic and mineralogical investigation of highly evolved carbonate–phlogopite-bearing kimberlites of the Kepino cluster, Arkhangelsk kimberlite province, Russia. The Kepino kimberlites are represented by volcanoclastic breccias and massive macrocrystic units within pipes as well as coherent porphyritic kimberlites within sills. The volcanoclastic units from pipes are similar in petrography and mineral composition to archetypal (Group 1) kimberlite, whereas the sills represent evolved kimberlites that exhibit a wide variation in amounts of carbonate and phlogopite. The late-stage evolution of kimberlitic melts involves increasing oxygen fugacity and fluid-phase evolution (forming carbonate segregations by exsolution, etc.). These processes are accompanied by the transformation of primary Al- and Ti-bearing phlogopite toward tetraferriphlogopite and the transition of spinel compositions from magmatic chromite to magnesian ulvöspinel and titanomagnetite. Similar primary kimberlitic melts emplaced as sills and pipes may be transitional to carbonatite melts in the shallow crust. The kimberlitic pipes are characterised by low carbonate amounts that may reflect the fluid degassing process during an explosive emplacement of the pipes. The Kepino kimberlite age, determined as 397.3 ± 1.2 Ma, indicates two episodes of ultramafic alkaline magmatism in the Arkhangelsk province, the first producing non-economic evolved kimberlites of the Kepino cluster and the second producing economic-grade diamondiferous kimberlites.

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“…Abiotic hydrocarbons (HCs) have been found in Earth's seafloor hydrothermal systems [1,2], crustal crystalline rocks [3], inclusions of mantle-derived diamonds [4][5][6][7], and meteorites [8], as well as on other planets [9]. Abiotic hydrocarbon production on the global scale is minor compared to hydrocarbon production by microbial processes or thermogenic degradation of organic matter in sedimentary rocks [10].…”

Section: Introductionmentioning

confidence: 99%

Formation of Hydrocarbons in the Presence of Native Iron under Upper Mantle Conditions: Experimental Constraints

et al. 2020

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The formation of hydrocarbons (HCs) upon interaction of metal and metal–carbon phases (solid Fe, Fe3C, Fe7C3, Ni, and liquid Fe–Ni alloys) with or without additional sources of carbon (graphite, diamond, carbonate, and H2O–CO2 fluids) was investigated in quenching experiments at 6.3 GPa and 1000–1400 °C, wherein hydrogen fugacity (fH2) was controlled by the Fe–FeO + H2O or Mo–MoO2 + H2O equilibria. The aim of the study was to investigate abiotic generation of hydrocarbons and to characterize the diversity of HC species that form in the presence of Fe/Ni metal phases at P–T–fH2 conditions typical of the upper mantle. The carbon donors were not fully depleted at experimental conditions. The ratio of H2 ingress and consumption rates depended on hydrogen permeability of the capsule material: runs with low-permeable Au capsules and/or high hydrogenation rates (H2O–CO2 fluid) yielded fluids equilibrated with the final assemblage of solid phases at fH2sample ≤ fH2buffer. The synthesized quenched fluids contained diverse HC species, predominantly light alkanes. The relative percentages of light alkane species were greater in higher temperature runs. At 1200 °C, light alkanes (C1 ≈ C2 > C3 > C4) formed either by direct hydrogenation of Fe3C or Fe7C3, or by hydrogenation of graphite/diamond in the presence of Fe3C, Fe7C3, and a liquid Fe–Ni alloy. The CH4/C2H6 ratio in the fluids decreased from 5 to 0.5 with decreasing iron activity and the C fraction increased in the series: Fe–Fe3C → Fe3C–Fe7C3 → Fe7C3–graphite → graphite. Fe3C–magnesite and Fe3C–H2O–CO2 systems at 1200 °C yielded magnesiowüstite and wüstite, respectively, and both produced C-enriched carbide Fe7C3 and mainly light alkanes (C1 ≈ C2 > C3 > C4). Thus, reactions of metal phases that simulate the composition of native iron with various carbon donors (graphite, diamond, carbonate, or H2O–CO2 fluid) at the upper mantle P–T conditions and enhanced fH2 can provide abiotic generation of complex hydrocarbon systems that predominantly contain light alkanes. The conditions favorable for HC formation exist in mantle zones, where slab-derived H2O-, CO2- and carbonate-bearing fluids interact with metal-saturated mantle.

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Prospects of search for diamondiferous kimberlites in the northeastern Siberian Platform

Cited by 41 publications

References 58 publications

Types of Xenogenic Olivine from Siberian Kimberlites

Types of Xenogenic Olivine from Siberian Kimberlites

Ultramafic Alkaline Rocks of Kepino Cluster, Arkhangelsk, Russia: Different Evolution of Kimberlite Melts in Sills and Pipes

Formation of Hydrocarbons in the Presence of Native Iron under Upper Mantle Conditions: Experimental Constraints

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