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

to 100 Ma), are typical Sn greisen deposits, and are associated with Li-F granitoid rocks. These Sn greisen deposits contain
notable amounts of W, as at the Tigrinoe deposit which occurs in the eastern part of the metallogenic belt adjacent to the Samarka
W skarn accretionary metallogenic belt (fig. 79). Intermediate-age deposits, formed in the late Late Cretaceous (75-85 Ma), are Sn
polymetallic vein deposits, as at Zimnee, which are interpreted as forming in coeval andesite, monzodiorite, and granodiorite
intrusions. These Sn polymetallic vein deposits occur in the western part of the Luzhkinsky metallogenic belt. The younger
deposits
1-1 Rhyolite
porphyry
Dacite
0 Granodiorite
- porphyry 1 - -
1 I Sandstone I Late Jurassic 8
Early Cretaceous
schist
- 0 40 M
Late Cretaceous 8 / Ore Veins
early Tertiary
I I Stockwork
/ Fault
Contact
VI Underground
level
Figure 89. Vysokogorskoe Sn silicate-sulfide vein deposit, Luzhkinsky metallogenic belt, Russian Southeast. Schematic cross
section. Adapted from Gonevchuk and others (1998).
formed in the Late Cretaceous and early Tertiary (70-60 Ma) and are Sn silica-sulfide vein deposits, as at Arsenyevsky which are
composed mainly of cassiterite and silicate minerals. These deposits are often generally spatially related to the older Sn
polymetallic deposits and formed simultaneously with Zn-Pb skarn deposits of the post-accretionary Taukha metallogenic belt to
the east. The Late Cretaceous and early Tertiary Sn silica-sulfide vein deposits are interpreted as related to the formation of
ultrapotassic rhyolite volcanic porphyries; however, any direct relation to intrusion rocks is quite obscure.
Tigrinoe Sn Greisen Deposit
The Tigrinoe Sn greisen deposit (fig. 91) (Rodionov and Rodionova, 1980; Rodionov and others, 1984; Ruchkin and
others, 1986; Rodionov and others, 1987; Korostelev and others, 1990; Gerasimov and others, 1990; Gonevchuk and Gonevchuk,
1991; Gonevchuk and others, 1998) is a complex Sn-W deposit consisting of: (1) a stockwork of quartz-topaz-micaceous greisen
along the contact of a massif of Li-F granite; (2) a linear stockwork consisting of a thick network (5 to 10 to 70 veinlets per meter)
of parallel north-south-trending quartz-topaz veins £rom 3 to 100 cm thick which are hosted in contact-metamorphosed
sedimentary rocks adjacent to the granite intrusion; and (3) a sulfide breccia pipe consisting of rock fragments of the stockwork
and greisen cemented by quartz with lesser carbonate, fluorite, and sulfides. Three stages of mineralization are distinguished: (1)
early quartz-molybdenite-bismuthinite; (2) middle-stage REE greisen of wolfiamite-cassiterite with high contents of Sc, Ni, and
Ta; and (3) late hydrothermal quartz-fluorite-carbonate-sulfide veins. In, Cd, Ag, and Se are enriched in sulfides of the two last
stages. A Rb-Sr age of the lithium-fluorine granite is 86 k 6 Ma with an initlal Sr ratio of 0.7093. A Rb-Sr age of the greisen is 73
-
+ 18 Ma with an initial Sr ratio of 0.7105. The average grade is 0.14% Sn and 0.045% W203. The deposit is of medium size.