The platinum-group minerals (PGM) of the Konder zoned alkali-ultrabasic massif, located east of the Aldan Shield, in fareastern Russia, are predominantly represented by isoferroplatinum of two generations, both with Fe contents ranging from 7.5 to 11.5 wt.%. A high-temperature isoferroplatinum is saturated with platinum-group-element (PGE) impurities: up to 5.3 Ir, 2.9 Os, and 1.8 Rh (all in wt.%). In contrast, the later isoferroplatinum contains lower levels of Ir, Os and Rh: less than 1.9 Ir, 1.0 Os, 0.6 Rh (in wt.%). The minor PGM are represented by a wide range of solid solutions in the system Os-Ir-Rh-Pt, tetraferroplatinum, tulameenite, hongshiite, minerals of erlichmanite-laurite and irarsite-hollingworthite series, sperrylite, bismuthides, antimonides, tellurides, stannides, and hydroxides. There are possibly new mineral species: native ruthenium, the Pd-dominant analogue of hongshiite, Pt 2 As 3 , the Pt-dominant analogue of konderite and inaglyite, and others minerals, which form rims around grains of isoferroplatinum and inclusions in it. A similar morphology and distribution as found with Pt 3 Fe are observed with gold, related to rare lenses of sulfide and impregnations in dunite (Cu-, Pt-, and Pd-bearing high-grade gold) and monzodiorite cutting dunite (low-impurity middle-and low-grade gold).
Vanadian-+hromian tourmaline (as much as 4.06 wl.Vo Y 2O3 and 2.387o Cr2O3) and vanadian muscovite (w much as 2.13Vo V2O3) occur in contact-metamorphosed carbonaceous metasediments of the hibrezhnaya anticlinal zone in himorye, Russia. Cfus'ias are compositionally zoned, showing depletion in V and Cr, and enrichment in Al, Mg and Fe, from core to-rim. Zoning is attributed to progressive decrease of VindCr contents in the host rock durilg the coune of crystal growth. Cr and V are incorporated according to the schemes: Cf* <+ Al3+ and V3* <-+ 1Mg2*,Fe2*,Mn2*;. The charge increase that results from the latter exchangeisconsideredtobecompensatedbytheconcomitantsubstitutionofrvAlforSiandbytheappearanceofvaca in the X site. The associated vanadian muscouite contains minor amounts of Mg, Fe, Ti and Na. An empirical formula calculated from results of an electron-microprobe analysis is (K1.9aNas.69)r2.03(Al3.34v0.29lvlgn.26Tis.65Fe0.0rx, (Si6.27Alr.i3)x.00O22(OH)2. Both minerals are products of contact metamorphism of V-Cr-bearing carbonaceous rocks.Keywords: vanadian=chromian tourmaline, vanadian 2Ml muscovite, electron-microprobe analysis, carbonaceous rocks, contact metamorphism, himorye, Russia. SOMMAIRENous avons trouv6 une tourmaline vanadifdre et chromifare (usqu'd 4.067o de V2O3 et 2.38Vo de Cr2O3' en Potds) et unp muscovite vanadifbre (usqu'd 2.737o V2O3) dans des m6tasddiments carbonac6s d'une aur6ole de contact dans la zone anticlinale de himorye, en Rusiie.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.