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USGS Professional Paper 1697 - Alaska Resources Library

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cum-North Pacific, (2) completion of opening of the Amerasia,<br />

Canada, and Eurasia Basins, (3) completion of accretion of the<br />

Wrangellia superterrane, (4) a change to dextral transpression<br />

in the eastern part of the Circum-North Pacific between the<br />

Kula oceanic plate and the North American continental margin,<br />

(5) oblique subduction of the Kula-Farallon oceanic ridge<br />

under the margins of Southern and southeastern <strong>Alaska</strong> and<br />

formation of associated metallogenic belts, and (6) northward<br />

migration of previously accreted terranes along the margin of<br />

the North American Cordillera.<br />

Specific Events for Late Cretaceous and<br />

Early Tertiary<br />

(1) Far to the south, at about 50º to 60º paleolatitude, the<br />

extensive Olyutorka island arc continued to form. Parts of the<br />

arc are preserved in the Nemuro (NE), Kronotskiy (KRO), and<br />

Olyutorka-Kamchatka (OKA), and Iruneisky (IR) island-arc<br />

terranes. Continuing to form in the Olyutorka arc were the<br />

Koryak Highlands metallogenic belt, which contains zoned<br />

72<br />

168<br />

co<br />

oc<br />

KY<br />

ia<br />

K<br />

yk<br />

km<br />

yk<br />

K<br />

km<br />

at<br />

at<br />

kw<br />

kw<br />

at<br />

wr<br />

FO<br />

oa<br />

SP<br />

bs<br />

bs<br />

co<br />

oa<br />

NWK<br />

om<br />

KO<br />

KMT<br />

oa<br />

om kn<br />

TI<br />

WCA<br />

om<br />

ECAoa<br />

om<br />

ECA<br />

cn DE<br />

KA<br />

MC<br />

SA<br />

BR<br />

kh CG<br />

SA<br />

gg<br />

oa<br />

om<br />

TE<br />

cn SL<br />

YK<br />

bs<br />

km<br />

KY<br />

DE<br />

oa<br />

PW<br />

TM<br />

PW<br />

CM<br />

AL<br />

CG<br />

YAK<br />

NY<br />

GD<br />

TG<br />

oa PW<br />

CM<br />

CG<br />

PAC<br />

168<br />

BR<br />

al<br />

156<br />

Arctic<br />

Ocean<br />

AL<br />

CG<br />

144<br />

CO<br />

d<br />

PW<br />

132<br />

56<br />

Late Cretaceous and Early Tertiary Metallogenic Belts (84 to 52 Ma) (figs. 102, 103) 217<br />

52<br />

72<br />

Pacific<br />

Ocean<br />

NAC<br />

156 144<br />

TI<br />

om<br />

BN<br />

gg<br />

om<br />

cr<br />

JU<br />

48<br />

mafic-ultramafic PGE and Cu massive sulfide deposits, and<br />

the Vatyn (VT) metallogenic belt, which contains volcanogenic<br />

Mn and Fe deposits. Also forming in Olyutorka arc was<br />

the Iruneiskiy (IR) metallogenic belt of porphyry Mo deposits.<br />

Associated with the arc was subduction of part of the adjacent<br />

oceanic plate to form the Vetlovskiy (VT) terrane. This arc and<br />

companion subduction zone migrated northward toward the<br />

Okhotsk-Chukotka continental-margin arc.<br />

(2) Farther west, the East Sikhote-Alin continental-margin<br />

arc (es) and related deposits continued activity. Forming<br />

as prt of the arc was the West Sakhalin (WSA) turbidite-basin<br />

terrane. Continuing to form in the East-Sikhote arc were the<br />

Kema, Lower Amur, Luzhkinsky, Segeevka, and Taukha<br />

metallogenic belts. Associated with the arc was oblique subduction<br />

of part of the Pacific oceanic plate (PAC) to form the<br />

Hikada (HI), Aniva (ANV), and Nabilsky (NAB) terranes.<br />

(3) The Okhotsk-Chukotka continental-margin arc continued<br />

activity. Parts of the arc are preserved in the Okhotsk-Chukotka<br />

volcanic-plutonic belt (oc) and related Penzhina (fore-arc)<br />

Sedimentary Basin (pn). Associated with the arc was subduc-<br />

64<br />

FO<br />

sk<br />

BK bo<br />

CSE<br />

cr<br />

QC<br />

LATE CRETACEOUS AND EARLY<br />

TERTIARY METALLOGENIC BELTS<br />

BN - Baranof<br />

BK - Bulkley<br />

CF - Catface<br />

CM - Chugach Mountains<br />

CSE - Central-Southeastern <strong>Alaska</strong><br />

ECA - East-Central <strong>Alaska</strong><br />

FLB - Fish Lake-Bralorne<br />

GB - Gambier<br />

JU - Juneau<br />

KMT - Kuskokwim Mountains<br />

MC - Maclaren<br />

NR<br />

PI<br />

cn<br />

0<br />

cn<br />

oa<br />

NAC<br />

FS gg gg PA<br />

GB<br />

CF<br />

gg<br />

132<br />

PR<br />

HO<br />

OC<br />

JFR<br />

56<br />

tt<br />

ns<br />

oa ns<br />

FO<br />

cr<br />

SK<br />

kl<br />

cr FLB<br />

BR ns<br />

TY sb<br />

kl<br />

NScn<br />

WA<br />

WA<br />

JF<br />

SZ<br />

CC<br />

cr<br />

cn<br />

ca<br />

800 km<br />

NWK - Northwestern<br />

Koyukuk Basin<br />

NS - Nelson<br />

PW - Prince William Sound<br />

SA - Southern <strong>Alaska</strong><br />

SK - Skeena<br />

SL - Surprise Lake<br />

SP - Seward Peninsula<br />

TM - Talkeetna Mountains<br />

TY - Tyaughton-Yalakom<br />

WCA - West-Central <strong>Alaska</strong><br />

YK - Yakobi<br />

om<br />

ca<br />

oa<br />

0 800 km<br />

Figure 103. Generalized map of major Late Cretaceous and early Tertiary metallogenic belts, overlap assemblages, and tectonically<br />

linked subduction-zone or accretionary-wedge terranes for <strong>Alaska</strong>, Canadian Cordillera, and adjacent offshore areas. Refer to text for<br />

description of metallogenic belts. Adapted from Nokleberg and others (1997b, 1998). Refer to figure 62 for explanation.<br />

48

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