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

Figure 123. Early to middle Tertiary (Middle Eocene through early Miocene - 52 to 23 Ma) stage of metallogenic-tectonic model.
Refer to text for explanation of metallogenic-tectonic events, to tables 3 and 4 for descriptions metallogenic belts and significant
deposits, and to figure 18 for explanation of abbreviations, symbols, and patterns. Adapted from Nokleberg and others (1997b.
1998,2000).
Specific Events for Early to Middle Tertiary
(1) The younger, bimodal volcanic and plutonic rocks of the youngest part of East-Sikhote Alin volcanic-plutonic belt
(es), mainly basalt, rhyolite, and associated granitic plutonic rocks, are herein interpreted as forming in a dextral-transpression
tectonic regime. During dextral-transpression, the the Central Sakhalin (CS) metallogenic belt of Au quartz vein and talc deposits
formed in the Aniva subduction zone terrane during associated hydrothermal activity.
(2) In the early Eocene, at about 50 Ma (Heiphitz and others, 1994; Brandon and others, 1997, 1998; Garver and others,
1998; Solo'ev and others, 1998; Konstantinovskaya, 1999), the Olyutorka island arc accreted against the West Kamchatka
accretionary-wedge terrane (WK; fig. 123) along the Vatyn thrust of Brandon and others (1997, 1998) which is interpreted as a
low-angle, seaward-dipping zone of obduction (Brandon and others, 1997, 1998; Ramthun and others, 1997). Alternatively, Geist
and others (1994) suggested that the Olyutorka arc and its companion subduction zone formed near the margin of Northeast Asia.
During accretion of the Olyutorka arc was formation of the Sredinny metallogenic belt (SR) of Au quartz vein and = metamorphic
REE vein(?) deposits.
(3) In the area of the central and southern Russian Far East, tectonic wedging occurred because of the accretion of the
Lndia plate against the Eurasia plate (Worall and others, 1996). The tectonic wedging resulted in sinistral displacement along the
reactivated Mongol-Okhotsk fault (MO) and dextral displacement along the Sakhalin-Hokkaido fault (SH) parallel to the margin
of the Russian Far East. A complex array of normal faults, en-echelon folds, and thrusts is interpreted as forming within and
adjacent to the tectonic wedge (Worall and others, 1996). The relation of sinistral movement along the reactivated Mongol-
Okhotsk fault and dextral movement along the Denali (DE), Tintina (TI), and related faults to the east in mainland Alaska in
unclear.
(4) The bimodal volcanic and plutonic rocks of the Kamchatka-Koryak volcanic-plutonic belt (kk) are herein interpreted
as forming in a sinistral tectonic regime. The Kamchatka-Koryak volcanic-plutonic belt constitutes the Cetnral Kamchatka arc.
Forming in the volcanic-plutonic belt was the Central Koryak (CKY) metallogenic belt which contains granitic-magmatism-