Инд. авторы:	Shatsky V.S., Ragozin A.L., Logvinova A.M., Wirth R., Kalinina V.V., Sobolev N.V.
Заглавие:	Diamond-rich placer deposits from iron-saturated mantle beneath the northeastern margin of the Siberian Craton
Библ. ссылка:	Shatsky V.S., Ragozin A.L., Logvinova A.M., Wirth R., Kalinina V.V., Sobolev N.V. Diamond-rich placer deposits from iron-saturated mantle beneath the northeastern margin of the Siberian Craton // Lithos. - 2020. - Vol.364-365. - Art.105514. - ISSN 0024-4937. - EISSN 1872-6143.
Идентиф-ры:	DOI: 10.1016/j.lithos.2020.105514; РИНЦ: 43259528; SCOPUS: 2-s2.0-85082923447; WoS: 000536183500011;
Реферат:	eng: We demonstrate for the first time the presence of iron carbides in placer diamonds from the northeastern region of the Siberian craton. It was found that the inclusions are polycrystalline aggregates, and iron carbides filling the fissures in the diamonds, thus providing clear evidence that the iron melts were captured first. Iron carbides were identified in diamonds containing mineral inclusions of eclogitic (Kfs, sulfide) and peridotitc (olivine) paragenesis. Iron carbides with minor amounts of admixed nickel were detected in a diamond sample containing an olivine inclusion (0.3 wt% Ni), indicating that the iron melt was not in equilibrium with the mantle peridotite.The low nickel contents of the iron carbides provide the best evidence that the subducted crust is a likely source of the iron melt. Diamonds containing carbide inclusions are characterised by a relatively low nitrogen aggregation state (5–35%), which is not consistent with the high temperature of the transition zone. Therefore, we have reason to assume that the studied diamonds are from the lower regions of the lithosphere. Considering all factors, the model for the interaction of the ascending asthenospheric mantle with the subducting slab seems to be more realistic. © 2020 Elsevier B.V.
Ключевые слова:	Russian Federation; subduction zone; source rock; placer deposit; peridotite; mantle structure; iron; fluid inclusion; diamond; Subducted crust; Siberian craton; Mantle; Iron carbide inclusions; Diamond; Siberian Craton;
Издано:	2020
Физ. хар-ка:	105514