Volume 22, 6, 2003
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Volume 22, 6, 2003 |
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Leonid M. Parfenov's scientific heritage 3
Tectonics and Geodynamics
L.M. Parfenov, N.A. Berzin, A.I. Khanchuk, G. Badarch, V.G.
Belichenko, A.N. Bulgatov, S.I. Dril, G.L. Kirillova, M.I. Kuzmin,
W.J. Nokleberg, A.V. Prokopiev, V.F. Timofeev, O. Tomurtogoo, H. Yang.
A model for the formation of orogenic belts in Central and Northeast Asia
7
A.P. Smelov, V.F. Timofeev. Terrane analysis and the
geodynamic model of the formation of the North Asian craton in the Early
Precambrian 42
V.S. Imaev, L.P. Imaeva, B.M. Koz’min, V.V. Nikolaev, R.M.
Semenov. Buffer seismogenic sructures between the Eurasian and Amurian
lithospheric plates in Southern Siberia 55
V.S. Oxman, A.V. Ganelin, S.D Sokolov., O.L. Morozov, F.F
Tret’yakov, S.A. Silantiev. Ophiolite belts of the Arctic regions,
Verkhoyansk-Chukotka orogenic area: a geodynamic model for their formation
62
G.E. Kaskevich. Transorogenic faults of East Yakutia
and adjacent regions 76
Stratigraphy
R.V. Kutygin, I.V. Budnikov, A.S. Biakov, A.G. Klets, V. S.
Grinenko. The reference section of the Dulgalah and Khalpirki horizons (Upper
Tatarian substage) of the Western Verkhoyansk Region 82
Geodynamics, Magmatism, and Metallogeny
S.M. Rodionov. The geodynamics and metallogeny of tin
in Eastern Russia 98
G.N. Gamyanin, N.A. Goryachev, N.S. Bortnikov, E.Yu. Anikina.
Types of silver mineralization in Verkhoyansk-Kolima mesozoides (geology,
mineralogy, genesis, and metallogeny) 113
V.A. Trunilina, Yu.S. Orlov, S.P. Roev. Composition of
magmatic rocks of the Charky volcanic-plutonic belt, and its geodynamic setting
127
A.I. Zaitsev. Modeling of the stages of isotope modification of the mantle
137
Index of papers published in the journal in 2003 143
L.M. Parfenov, N.A. Berzin,
A.I. Khanchuk, G. Badarch, V.G. Belichenko, A.N. Bulgatov, S.I. Dril, G.L.
Kirillova, M.I. Kuzmin, W.J. Nokleberg, A.V. Prokopyev, V.F. Timofeev, O.
Tomurtogoo, H. Yang
A model for the formation of orogenic belts in Central and Northeast
Asia
A model for the formation of Late Riphean, Paleozoic and Early Mesozoic
orogenic belts of Central and Northeast Asia, framing the North Asian and
Sino-Korean cratons, and of Mesozoic and Cenozoic orogenic belts of the
northwestern margin of the Pacific Ocean is substantiated in the context of
plate tectonics. Systems of independent island arcs of Late Riphean,
Vendian-Cambrian and Silurian-Devonian age are established that accreted to the
North Asian craton to form Late Riphean, Early Paleozoic and Late Paleozoic
orogenic belts. The formation of the Late Paleozoic-Early Mesozoic
Mongol-Okhotsk and Solonker orogenic belts was related to the closure of ocean
basins that existed at their place and to subduction of the oceanic crust
beneath the adjacent continental margins upon which above-subduction magmatic
arcs were located.
The Mesozoic and Cenozoic orogenic belts of the northwestern margin of the
Pacific Ocean were forming in the process of convergence of the paleo-Pacific
Ocean and North Asian plates. Mutual convergence of the oceanic and continental
plates was accompanied by rifting, opening and subsequent closing of minor
ocean basins in the rear of active continental margins and island arcs.
The formation of the orogenic belts discussed in this paper was accompanied by
large (hundreds and thousands of kilometers) longitudinal strike-slip motions
nearly subparallel to the continent-ocean boundary. This defined many
characteristic features of the orogenic belts, such as their rectilinear or
slightly curved shape in plan, discontinuous extension, lens-like thinning-out
termination, and the absence of characteristic collisional granitoids and
foredeeps conjugate to orogenic belts.
A.P. Smelov, V.F. Timofeev
Terrane analysis and the geodynamic model of the formation of
the North Asian craton in the Early Precambrian
Principles and methods of the terrane analysis are discussed as applied to the
study of the tectonic structure of the crystalline basement of ancient cratons.
L.M. Parfenov was the first to suggest using the terrane approach to solving
this problem. The terrane analysis made it possible to establish orogenic belts
and stable cratonal areas of different age and origin within the basement, as
well as to determine their inner structure. As exemplified by the North Asian
craton, it is shown that the formation of the continental crust involves three
main tectonic stages: 1 – Late Archean (3.0–2.6 Ga) when early cratons were
formed, 2 – Paleoproterozoic (2.1–1.9 Ga) when collision of the Archean
continents and microcontinents produced orogenic belts (stage of formation of
the North Asian craton proper as part of supercontinent Pangea, and 3 –
Mesoproterozoic (< 1.4 Ga) when the formation of orogenic belts at the margins
of the craton occurred. Each orogenic stage is shown to be followed by a
rifting stage. A series of paleotectonic reconstructions is presented showing
the main stages in the emplacement and evolution of the basement of the North
Asian craton.
V.S. Imaev, L.P. Imaeva, B.M. Koz’min,
V.V. Nikolaev, R.M. Semenov
Buffer seismogenic sructures between the Eurasian and Amurian
lithospheric plates in Southern Siberia
The area of interaction of the Eurasian and Amurian plates in Southern Siberia
between Lake Baikal and the Sea of Okhotsk is investigated basing on the
results of the study of seismicity, focal mechanisms of earthquakes, tectonic
features, etc. in the region. The Transbaikal and Stanovoy blocks are
established there representing a class of buffer structures. It is shown that
the present-day seismotectonic processes taking place at the boundary of the
buffer structures are related to convergence between the Amurian and Eurasian
plates.
V.S. Oxman, A.V. Ganelin, S.D.
Sokolov, O.L. Morozov, F.F. Tretyakov, S.A. Silantyev
Ophiolite belts of the Arctic regions,
Verkhoyansk-Chukotka orogenic area: a geodynamic model for their formation
Ophiolite belts of the Chersky and South-Anyuy suture (SAS) have been
recognized in the Verkhoyansk-Chukotka orogenic area (Arctic and Sub-Arctic)
confined to the axial parts of the Verkhoyansk-Kolyma and Novosibirsk-Chukotka
(Chukotka-Anyuy) collision orogens, repectively. Ophiolite fragments of the
Chersky belt are the relics of the Earth’s crust of an Early Paleozoic back-arc,
or marginal-sea basin; and ophiolites of the South-Anyuy suture, of the Late
Paleozoic-Early Mesozoic Anyuy-Angayucham Ocean. A conclusion is made about SAS
continuation to the north-west of Alaska, where the Kobuk ophiolite suture is
its likely analogue. The indicative oceanic complexes of both sutures of the
Late Paleozoic-Mesozoic represent fragments of the basin which separated
Eurasia and Northern America in the Paleozoic-Early Mesozoic; and Eurasia and
Chukotka, in the Late Mesozoic. Subsequent stages of metamorphism of ophiolites
and associated volcanogenic-sedimentary rocks are related to the processes of
amalgamation, accretion and collision of the Kolyma-Omolon and Chukotka
microcontinents to the North-Asian and Siberian cratons.
G.E. Kaskevich
Transorogenic faults of East Yakutia and adjacent
regions
Characteristics of transorogenic faults (transverse structural forms)
recognized in the course of structural-geomorphological analysis are given, and
their expression in the modern topography of East Yakutia and adjacent regions
is described.
R.V.Kutygin,
I.V.Budnikov, A.S.Biakov, A.G.Klets, V. S. Grinenko
The reference section of the Dulgalakh and Khalpirki horizons
(Upper Tatarian substage) of the West Verkhoyansk Region
A continuous detailed (layer-by-layer) section of the Dulgalakh and Khalpirki horizons of the Upper Tatarian in the West Verkhoyansk Region (Khalpirki River Basin) is given. The horizons represent two large transgressive-regressive sedimentary stages. The Brachiopod and Bivalve zonal sequences are described; characteristics of the established biostratigraphic zones and portraitures of the most typical bivalve taxons are offered. The investigated section is presented as a hypostratotype for the Dulgalakh horizon and as a parastratotype for the Khalpirki horizon. Correlation is made of deposits assigned to the Dulgalakh and Khalpirki horizons within the Verkhoyansk Region.
G.N. Gamyanin,
N.A. Goryachev, N.S. Bortnikov, E.Yu. Anikina
Types of silver mineralization in Verkhoyansk-Kolyma
mesozoides (geology, mineralogy, genesis, and metallogeny)
The area of the Verkhoyansk-Kolyma mesozoides is a large silver-bearing
province. Various types of mineralization are developed there including
epithermal silver-antimony, volcanogenic argentiferous
pyrite-barite-polymetallic, silver-polysulphide-tin, silver-rare metal, and
silver-lead-zinc mineralization. The geological history of the region involves
the following stages in the formation of various types of silvern
mineralization. The earliest is argentiferous barite-pyrite-polymetallic
mineralization related to volcanic arcs. It is represented by Kuroko-type
dynamometamorphosed deposits of Late Jurassic (about 150 Ma) age.
Silver-polysulphide-tin mineralization formed in the period of accretion and
was related to granitoid tinny systems (146-120 Ma). Silver-rare metal and
silver-lead-zinc mineralizations, which were preceded by the emplacement of
acid subvolcanic dikes aged at 80-90 Ma, are post-accretionary. Epithermal
silver-antimony mineralization also formed in the post-accretionary period and
was related to tectonomagmatic activation of deep-seated faults of mesozoides.
It has an age of less than 80 Ma. The distribution of various types of
mineralization is mainly controlled by such geological features as regional
fold structures, large deep-seated faults and volcanogenic belts. The
Uyandina-Yasachnensk silver-bearing metallogenic zone with argentiferous
barite-pyrite-polymetallic and epithermal silver-antimony mineralization, the
Adycha-Taryn zone with silver mineralization of granitoid trend and epithermal
silver-antimony mineralization, and the West Verkhoyansk and South Verkhoyansk
zones with silver mineralization of granitoid trend have been established. All
the deposits described above are assigned to a low-temperature (280-120°C) type,
with relatively low salt concentrations (9.2 3.3 % NaCl eq.) at
silver-polysulphide-tin deposits increasing up to 29 %. NaCl eq. at
silver-lead-zinc deposits. The largest and economically most important are
silver-lead-zinc deposits, formed at shallow depths. Gases at the deposits of
granitoid trend are dominated by CO2 (45.3–94.2 rel. %), while at
silver-antimony deposits nitrogen is important (up to 67.1 rel.%). Studies of
stable and radiogenic isotopes revealed similarity of many isotope parameters
of silver mineralization of granitoid systems and their significant difference
from silver mineralization of the volcanic series.
V.A. Trunilina, Yu.S. Orlov, S.P. Roev
The Charkynskiy volcano-plutonic belt is located near the collision zone
between the Verkhoyansk continental margin and the Kolyma-Omolon microcontinent,
in front of the Main granitoid belt. Its location is controlled by the regional
fault zone. This paper presents for the first time petrographic, petrochemical
and geochemical data for the Middle Jurassic volcanic rocks of the belt and new
data on the composition of Late Jurassic subvolcanic and hypabyssal formations
intruding them. The typomorphic features of the rocks and minerals suggest that
the belt was formed most probably in the active continental margin environment.