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USGS Professional Paper 1697 - Alaska Resources Library

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and Omolon (OM) cratonal terranes, which were previously<br />

rifted from the North Asian Craton (NSC), and the Viliga (VL)<br />

passive continental-margin terranes, which were previously<br />

rifted from the North Asian Craton Margin (NSV). Behind the<br />

arc were fragments of prior Devonian to Pennsylvanian islandarc<br />

terranes, including the Beryozovka turbidite-basin (BE),<br />

Oloy (OL), and Yarakvaam (YA) island-arc terranes.<br />

(4) The Angayucham Ocean (Kobuck Sea of Plafker and<br />

Berg, 1994), along with the South Anyui Ocean, continued to<br />

receive sparse continental-derived detritus. Previously rifted<br />

terranes, including the Kilbuck-Idono cratonal (KI) and the<br />

combined Nixon Fork-Dillinger-Mystic passive continentalmargin<br />

(NX, DL, MY) terranes, were near the North American<br />

Craton Margin.<br />

(5) The dextral-slip imbrication of the Stikinia-Quesnellia<br />

arc and associated subduction-zone terranes continued<br />

MONAKIN<br />

ARC - mo<br />

COLL<br />

SMA, KB, BD<br />

?<br />

(BU)<br />

UMLEKAN<br />

ARC - uo<br />

TALKEETNA<br />

ARC<br />

MO<br />

?<br />

CG<br />

NSS<br />

uz<br />

WRA<br />

(PE)<br />

UL<br />

WRA<br />

(AX)<br />

UDA ARC<br />

ud<br />

TD<br />

MONGOL-<br />

OKHOTSK TL<br />

OCEAN<br />

GL<br />

KONY-MURGAL<br />

ARC<br />

KM<br />

0 800 KM<br />

0 800 MI<br />

o o<br />

At about 25 or 45 latitude?<br />

TM,<br />

AP<br />

BONANZA<br />

ARC<br />

80<br />

o<br />

AK<br />

PA<br />

NSC<br />

OK<br />

?<br />

?<br />

NSV.<br />

KN<br />

VL<br />

BA<br />

o<br />

25<br />

MT<br />

CD<br />

BR IP<br />

CACHE CREEK<br />

WRA<br />

(WR)<br />

OCEAN<br />

CG<br />

OIMYAKON<br />

OCEAN<br />

OV<br />

RA<br />

PR<br />

OM<br />

OL<br />

OL<br />

(TA, KT)<br />

SOUTH<br />

ANYUI<br />

OCEAN<br />

COLL<br />

YA<br />

AC<br />

ANCESTRAL PACIFIC OCEAN<br />

o<br />

60<br />

along the Tally Ho shear zone (Hansen and others, 1990;<br />

Hart, 1995) (inset, fig. 43). Part of the Tally Ho shear zone<br />

may occur be defined by a string of fault-bounded(?) ultramafic<br />

rocks that occur within the Yukon-Tanana terrane in<br />

northern southeastern <strong>Alaska</strong> (Himmelberg and others, 1985).<br />

Alternatively, the present-day configuration of the Stikinia-Quesnellia<br />

island-arc and associated subduction-zone<br />

terranes may have formed by oroclinal warping in response<br />

to a combination of oblique convergence and arc migration<br />

toward the companion subduction zone of the Cache Creek<br />

terrane (Mihalynuk and others, 1994) (not depicted in fig.<br />

43). Oroclinal warping is interpreted as forming in response<br />

to (1) oblique-sinstral convergence between the ancestral<br />

Pacific oceanic plate and the Stikinia-Quesnellia arc, and (2)<br />

arc migration toward the companion subduction zone (trench<br />

rollback), similar to tectonics of the present-day Banda arc in<br />

ZL<br />

ANGAYU-<br />

CHAM<br />

OCEAN<br />

ARG<br />

AL, KH<br />

ALAZEYA<br />

ARC<br />

208 to 193 Ma<br />

Early Jurassic Metallogenic Belts (208 to 193 Ma; fig. 42) 99<br />

NAM<br />

KI<br />

NX, DL,<br />

MY<br />

GOOD-<br />

NEWS<br />

OCEAN<br />

KL<br />

CC<br />

NAC<br />

NAC<br />

SV<br />

SEVENTYMILE<br />

OCEAN<br />

o<br />

At about 25 latitude<br />

YT<br />

TALLY HO SINISTRAL<br />

SHEAR ZONE<br />

TC,<br />

GL<br />

Hazelton<br />

Group<br />

CM<br />

SV<br />

ST<br />

o<br />

25<br />

NAM<br />

QN<br />

METALLOGENIC BELTS<br />

AP - <strong>Alaska</strong> Peninsula<br />

CM - Coast Mountains<br />

CMN - Copper Mountain<br />

North<br />

CMS - Copper Mountain<br />

South<br />

GL - Galore<br />

GU - Guichon<br />

IP - Island Porphyry<br />

KL - Klotassin<br />

TC - Texas Creek<br />

TM - Talkeetna Mountains<br />

TO - Toodoggone<br />

CC<br />

CACHE CREEK<br />

OCEAN<br />

NAC<br />

SM<br />

SLIDE MOUNTAIN<br />

OCEAN<br />

NAM<br />

o<br />

40<br />

STIKINIA-<br />

QUESNELLIA Rossland<br />

ARC Group<br />

Takla QN<br />

SM<br />

Group<br />

KO<br />

TO, CMN,<br />

CMS, GU<br />

Figure 43. Early Jurassic (Hettangian through Pliensbachian—208 to 193 Ma) stage of metallogenic-tectonic model for the Russian<br />

Far East, <strong>Alaska</strong>, and the Canadian Cordillera and adjacent offshore areas. Refer to text for explanation of metallogenic-tectonic events,<br />

to tables 3 and 4 for descriptions metallogenic belts and significant deposits, and to figure 18 for explanation of abbreviations, symbols,<br />

and patterns. Adapted from Nokleberg and others (1997b, 1998, 2000).<br />

?

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