Research output: Contribution to journal › Article › peer-review
Prospects of search for diamondiferous kimberlites in the northeastern Siberian Platform. / Sobolev, N. V.; Sobolev, A. V.; Tomilenko, A. A. et al.
In: Russian Geology and Geophysics, Vol. 59, No. 10, 01.10.2018, p. 1365-1379.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Prospects of search for diamondiferous kimberlites in the northeastern Siberian Platform
AU - Sobolev, N. V.
AU - Sobolev, A. V.
AU - Tomilenko, A. A.
AU - Kuz'min, D. V.
AU - Grakhanov, S. A.
AU - Batanova, V. G.
AU - Logvinova, A. M.
AU - Bul'bak, T. A.
AU - Kostrovitskii, S. I.
AU - Yakovlev, D. A.
AU - Fedorova, E. N.
AU - Anastasenko, G. F.
AU - Nikolenko, E. I.
AU - Tolstov, A. V.
AU - Reutskii, V. N.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - The objects of study are Triassic hypabyssal diamondiferous kimberlites with an age of 220-245 Ma, containing macrocrysts of unaltered olivine. The latter are close in the time of formation to the main stage of intrusion of the Siberian Trap Province (252 Ma), which lasted less than 1 Myr. A comparative high-precision analytical study of the Ti, Ca, Cr, and Al impurity patterns in about 1000 olivine macrocryst samples with a forsterite content Fo = (100Mg/(Mg + Fe)) of 78 to 93 has demonstrated the effect of traps on the lithospheric composition. A comprehensive comparative study of diamonds from northern placers and Triassic kimberlites, including determination of their carbon isotope composition, was performed. Chromatography-mass-spectroscopic analysis of submicron fluid inclusions in diamonds from northern placers and kimberlites has shown predominant hydrocarbons of a wide range of compositions and subordinate contents of N2, H2O, and CO2. These findings, together with the results of previous studies of subcalcic Cr-pyropes and diamonds found in the Lower Carboniferous gritstones of the Kyutyungde graben, lead to the conclusion that the Toluopka kimberlite field is promising for Paleozoic kimberlites. The results of comprehensive studies of diamonds and indicator minerals and U/Pb isotope dating of numerous detrital zircon samples from the basal horizon of the Carnian Stage (Upper Triassic) of the Bulkur site in the lower reaches of the Lena River suggest the presence of diamondiferous kimberlites within the northeastern Siberian Platform. The age of the probable primary diamond sources in the study area can be evaluated by an integrated U/Pb isotope dating of zircons, perovskites, and rutiles from the developed diamond placers and the basal horizon of the Carnian Stage.
AB - The objects of study are Triassic hypabyssal diamondiferous kimberlites with an age of 220-245 Ma, containing macrocrysts of unaltered olivine. The latter are close in the time of formation to the main stage of intrusion of the Siberian Trap Province (252 Ma), which lasted less than 1 Myr. A comparative high-precision analytical study of the Ti, Ca, Cr, and Al impurity patterns in about 1000 olivine macrocryst samples with a forsterite content Fo = (100Mg/(Mg + Fe)) of 78 to 93 has demonstrated the effect of traps on the lithospheric composition. A comprehensive comparative study of diamonds from northern placers and Triassic kimberlites, including determination of their carbon isotope composition, was performed. Chromatography-mass-spectroscopic analysis of submicron fluid inclusions in diamonds from northern placers and kimberlites has shown predominant hydrocarbons of a wide range of compositions and subordinate contents of N2, H2O, and CO2. These findings, together with the results of previous studies of subcalcic Cr-pyropes and diamonds found in the Lower Carboniferous gritstones of the Kyutyungde graben, lead to the conclusion that the Toluopka kimberlite field is promising for Paleozoic kimberlites. The results of comprehensive studies of diamonds and indicator minerals and U/Pb isotope dating of numerous detrital zircon samples from the basal horizon of the Carnian Stage (Upper Triassic) of the Bulkur site in the lower reaches of the Lena River suggest the presence of diamondiferous kimberlites within the northeastern Siberian Platform. The age of the probable primary diamond sources in the study area can be evaluated by an integrated U/Pb isotope dating of zircons, perovskites, and rutiles from the developed diamond placers and the basal horizon of the Carnian Stage.
KW - diamond
KW - hypabyssal kimberlite
KW - lithospheric mantle
KW - Mesozoic
KW - olivine
KW - perovskite
KW - rutile
KW - Siberian Platform
KW - U/Pb isotope dating
KW - zircon
KW - GARNETS
KW - INCLUSIONS
KW - LITHOSPHERIC MANTLE
KW - INFRARED-ABSORPTION
KW - U-PB
KW - HYPABYSSAL KIMBERLITES
KW - PHASE-COMPOSITION
KW - KOKCHETAV MASSIF
KW - DIAMONDS
KW - OLIVINE
UR - http://www.scopus.com/inward/record.url?scp=85054924904&partnerID=8YFLogxK
U2 - 10.1016/j.rgg.2018.09.012
DO - 10.1016/j.rgg.2018.09.012
M3 - Article
AN - SCOPUS:85054924904
VL - 59
SP - 1365
EP - 1379
JO - Russian Geology and Geophysics
JF - Russian Geology and Geophysics
SN - 1068-7971
IS - 10
ER -
ID: 17115087