USGS Professional Paper 1697 - Alaska Resources Library

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) that 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.
ROTATION
esa
SH
60 o
MO
COLL
CS
NSC
(ASC,
IOC)
PAC
NSV
SR, KV
kc
(SH, TR, NE) (OKA, IR,
KRO, WK)
COLL
KAMCHATKA-
KORYAK
ARC kk
VT CENTRAL
KAMCHATKA
ARC
al
sh
atb
bw
al
GK
?
(3) In the area of the central and southern Russian Far East,
tectonic wedging occurred because of the accretion of the India
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-related deposits. Forming in the back-arc
part of the arc was the Kvinumsky (KV) metallogenic belt of
hornblende peridotite and gabbroic Cu-Ni deposits.
(5) Rifting commenced at about 50 Ma along the Gakkel
Ridge (GK; northern extension of the mid-Atlantic ridge) and
?
?
80
?
o
COLL
0 800 km
ALEUTIAN-WRANGELL ARC
0 800 mi 52 to 23 Ma
Early to Middle Tertiary Metallogenic Belts (52 to 23 Ma; figs. 102, 103) 263
OT
LO
CKY
eb
ab
ab
?
NF
?
?
(am)
yk
COLL
al
PW
cb
AL
DE
CO
NAC
COLLAGE
OF
RIFTED
TERRANES
NAM
TI
YAK
NAM
PAC
METALLOGENIC BELTS
CKY - Central Koryak
CS - Central Sakhalin
KV - Kvinumnsky
OC - Owl Creek
OT - Olyutor
SR - Sredinny
NAC
COLL
?
NAC
?
JFR
QC
OC
JF
SZ, OC,
HO
CASCADE
ARC
Figure 123. Early to middle Tertiary (Middle Eocene through early Miocene—52 to 23 Ma) stage of metallogenic-tectonic model for
the Russian Far East, Alaska, and the Canadian Cordillera and adjacent offshore areas. Refer to text for explanation of metallogenictectonic
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).
CC
ca