Metallogenesis and Tectonics of the Russian Far East, Alaska, and ...

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rzl Dacite (Late Cretaceous)
Rhyolite (Late Cretaceous)
mCkelrer,
/_/ Ore Body
figurn 74. hwomiah Sngmkm depask Badzhd€mp-Wngan metallogenic belt, Russian Sou#~easl AdnpM Irw
fiwlcvrjrk Pnd &el% (1W).
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Tk bFe & well b w r Khingan ~ Sn greisen deposit (fig. 75) (Ognyanov, 1986) is of hypabydm lUlld OCCUIT im P
*d pre Wep ef ~ y ~ explosion ~ breccia a which l cut a sequence of felsic vokmic rocks T'bdq&kc& w
15 w lplwa h 10 b 40 m m a and 100 to 400-500 m which are concentrated down-dip h r a p n m h l kasb zaaa W
25&3&l m.scrw. The zuw bas ken traced to depths of over 1200 m. At the upper levels o-f hr dv& Eba bmecia ir repbed
by &cbs #d at the dsprbs of 703-800 m, the breccia is replaced by quartz-muscovite (hi@)-topaz g~kisan. .- d hk &re
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-iVqmE--
@. Arsenopyrite, marcasite, loellingite, chalcopyrite, and Bi-- an subartbdq b hpdl i WqrrHd M ptohbly m-1~ related to subalkaline potassium granite with a K-Ar of 8040 kia and W &Am
k ~$78 Ma with an initial Sr isotopic ratio of 0.7123 (Gonevchuk and 0th- LP91). T% bb m
roEe W IWh.Tba deposit is of large and averages 0.6-0.7% Sn.
-BRee Sn Quartz Vein Deposit
The Verklmeb~dzhanskoe Sn quartz vein deposit (Ognyanov, 1986) IS hosted in Late Proterozoic dhm& Mw Wr
hflu&m mck. The deposit occurs at a Wonic contact of the dolomite with Late Proterozoic scbift. "Ih
of mUo& pumtz-dklc lenses which range from 50 to 80 rn along stnke, and extend up to 70 m ckiw'n~d 8 SWbWn ,-.
thick d IQ f~ 12 m % &pdt a c e for about 1,300 m. The dominate late-stage ore minerals are e - 0 . d - 1
@ou- jamedrmh) T'k ~ u b ~ tearlier-htage e , ore-mmb me quartz, casdcrite, and ars-ts~ A.l!kMi& &xi&&
k~cluh ed&a, and dokte. B d ha stdim- a d va!crmic mk~ am exmly rircb ift@ (w & IUMS~. &-
Late Cketwum rhyolla &yq anJ; whih codam gero~cally mo- Sn ( a h O.U95%). is imqmtad w thl ww$y
chbg hydm&rmal *ration. 'k &posit is small and contaw an av-8~ oPW-2.W Ski.
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for tba 6 90, wb& h d
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