USGS Professional Paper 1697 - Alaska Resources Library

Subterrane—A fault-bounded unit within a terrane that exhibits
similar, but not identical geologic history relative to
another fault-bounded unit in the same terrane.
Superterrane—An aggregate of terranes that is interpreted to
share either a similar stratigraphic kindred or affinity or
a common geologic history prior to accretion (Moore,
1992). An approximate synonym is composite terrane
(Plafker and Berg, 1994).
Tectonic linkage—The interpreted association of a suite of
coeval tectonic units that formed in the same region and
as the result of the same tectonic processes. An example
is the linking of a coeval continental-margin arc, forearc
deposits, a back-arc rift assemblage, and a subduction-zone
complex, all related to the underthrusting of a
continental margin by oceanic crust.
Tectonostratigraphic terrane—A fault-bounded geologic entity
or fragment characterized by a distinctive geologic history
that differs markedly from that of adjacent terranes
(Jones and others, 1983; Howell and others, 1985).
Transform continental-margin arc—An igneous belt of coeval
plutonic and volcanic rocks and associated sedimentary
rocks that formed along a transform fault that cuts the
margin of a craton, passive continental margin, and (or)
collage of terranes accreted to a continental margin.
Turbidite basin terrane—Fragment of a sedimentary basin
filled with deep-marine clastic deposits in either an orogenic
fore-arc or back-arc setting. May include continental-slope
and continental-rise turbidite, and submarinefan
turbidite deposited on oceanic crust. May include
minor epiclastic and volcaniclastic deposits.
Mineral Deposit Models
For the metallogenic analysis of the Russian Far East,
Alaska, and the Canadian Cordillera, metalliferous and
selected nonmetalliferous lode deposits are classified into
various models or types as described in Nokleberg and others
(1996, 1997a) and as listed in table 1. This classification of
mineral deposits was chiefly derived mainly from the mineral
deposit types of Eckstrand (1984), Cox and Singer (1986),
Bliss and others (1992), and Eckstrand and others (1995), but
includes some modifications. The mineral deposit types are
systematically arranged to describe the essential properties of
a class of mineral deposits. Some mineral deposit models are
descriptive (empirical), in which instance the various attributes
are recognized as essential, even though their relationships
may not be known. An example of a descriptive mineral
deposit type is the basaltic Cu type in which the essential
attribute is empirical datum of a geologic association of Cu
sulfides with relatively Cu-rich metabasalt or greenstone.
Other deposit types are genetic (theoretical), in which case
the attributes are related through some fundamental concept.
An example is the W skarn deposit type in which the essential
attribute is the genetic process of contact metasomatism is the
essential attribute. For additional information on the methodology
of mineral deposit types, see Eckstrand (1984), Cox and
Singer (1986), and Bliss (1992). The lode deposit models that
are utilized in this report and previous, related publications
(Nokleberg and others, 1996, 1997a) are listed in table 1 and
are grouped according to host rock lithologies and (or) origin.
Lode deposit models that share a common origin, such as contact
metasomatic deposits, or porphyry deposits, are grouped
together under a single heading.
Acknowledgments
Acknowledgments 7
We thank the many geologists with whom we have
worked for their valuable expertise in each region of Alaska,
the Russian Far East, Hokkaido Island of Japan, the Canadian
Cordillera, and the U.S.A. Pacific Northwest. We also thank
our managers who have so kindly supported our project studies.
Specifically, we thank J.N. Aleinikoff, Yu.V. Arkhipov,
H.C. Berg, R.B. Blodgett, S.E. Box, D.A. Brew, M.D. Bulgakova,
Ch. B. Borukaev, D.C. Bradley, Howard Brooks, J.
Decker, J.M. Duke, Cynthia Dusel-Bacon, Robert B. Forbes,
H.L. Foster, J.M. Franklin, V.V. Gaiduk, B.M. Gamble, V.V.
Golozubov, Arthur Grantz, D.G. Howell, C.W. Jefferson, D.L.
Jones, S.M. Karl, S.V. Kovalenko, W.C. McClelland, E.M.
MacKevett, Jr., A.V. Makhinin, M.V. Martynyuk, M.L. Miller,
T.P. Miller, L.Ph. Mishin, E.J. Moll-Stalcup, T.E. Moore, S.W.
Nelson, V.S. Oxman, S.A. Palanjan, I.V. Panchenko, T.L. Pavlis,
L.I. Popeko, A.V. Prokopiev, J.C. Reed, Jr., D.H. Richter,
S.M. Roeske, N.J. Silberling, the late G.M. Sosunov, A.B.
Till, F.F. Tret’yakov, A.N. Vishnevskiy, I.G. Volkodav, W.K.
Wallace, G.R. Winkler, the late L.P. Zonenshain, and Yu.P.
Zmievsky for their many beneficial discussions. We thank the
late Ch.B. Borykaev, the late William R. Greenwood, Donald
Grybeck, B.A. Morgan III, I.Ya. Nekrasov, A.T. Ovenshine,
P.P. Hearn, T.E. Smith, D.J. Templeman-Kluit, and W.H. White
for their encouragement and support of the project. We thank
S.G. Byalobzhesky, A. Grantz, K.G. Mackey, B.A. Natal’in,
L.M. Natapov, G. Plafker, W.W. Patton, Jr., S.D. Sokolov,
G.M. Sosunov, R.W. Tabor, N.V. Tsukanov, and T.L. Vallier
for their very fine work on the detailed terrane and overlap
assemblage map of the Circum-North Pacific (Nokleberg
and others, 1994a) and for many discussions of the tectonics
of the region. We thank various Russian interpreters, including
the late Lidiya I. Kovbas, Tatyana L. Koryakina, Tatyana
N. Velikoda, Elena P. Burak, and Elena V. Alekseenko for
their skilled assistance during long and complex scientific
dialogues, and for translation of complex geologic descriptions
and references. We thank B.A. Natal’in for participation
in the compilation and synthesis of a portion of the Russian
Southeast part of the terrane map of the Circum-North Pacific.
We thank Julie A. Nokleberg for computer drafting of most
of the metallogenic belt figures and for most of the mineral
deposit figures for Alaska and the Russian Far East. We thank