『Abstract
Northern Eurasia consists of the East European, Siberian, North
China, and Altai-Tarim cratons, fragments of the supercontinent
Rodinia, and the orogens of the Baikalides, Timanides, Uralides,
Altaids, and Mongolides. These can be collectively classified
as the Central Asian supercollage. The Baikalides and Timanides
host Meso- and Neoproterozoic magmatic arc terranes that were
sutured with the adjacent East European and Siberian cratons in
the end of the Neoproterozoic. The Paleozoic part of the supercollage
consists of three almost synchronous and subparallel Neoproterozoic
to Paleozoic magmatic arc and turbidite superterranes, as well
as overlap assemblages, bent into the world's largest oroclines.
Analysis of their structural pattern, supported by paleontological,
lithological, and paleomagnetic data, indicates that these superterranes
might have been produced via formation of arc-backarc systems
at the margin of combined North China, East European and Siberian
cratons and then deformed during Paleozoic westward-directed strike-slip
translation between the clockwise rotating Siberian and eastward
moving North China cratons. It is proposed that this development
took place against the respective breakup of the above-mentioned
cratons from the northern and southern margins of Eastern Europe
in the Neoproterozoic, initially as a group of cratons called
Nena, which reassembled in late Paleozoic to early Mesozoic times
into Laurasia, part of the new supercontinent Pangea.
In Mesozoic-Cenozoic times, the subduction-related continental
growth of northern Eurasia continued in the Nipponide, Kamchatka
and Kolyma-Alaska orogenic collages of the northern Circum-Pacific,
which consist of Paleozoic to Cenozoic turbidite to island arc
superterranes and overlap assemblages, generally younging towards
the Pacific oceanic plate and also severely oroclinally bent.
It is proposed that terranes of the Kolyma-Alaska and Kamchatka
collages were translated westward, dextrally relative to Siberia,
whereas Nipponides were translated northward, relative to North
China, similarly to the better constrained Mesozoic-Cenozoic reconstructions
of southeastern Asia. The two groups of collages started to collide
along the Mongol-Okhotsk suture zone in the south of the Siberian
craton in the end of the Mesozoic and then continued to collide
along the presently active plate boundary at the island of Sakhalin.
The proposed scenario suggests similarities in Paleozoic evolution
of the Central Asian and Mesozoic-Cenozoic evolution of the northern
Circum-Pacific supercollages, both possibly formed in response
to westward subduction and related strike-slip translation of
the (Paleo)-Pacific oceanic plates. The individual superterranes
might have been consequently translated for as much as 4000-6000
km and oroclinally bent during such translation or/and rotation
of the adjacent cratons.
Keywords: Central Asian supercollage; Altaids; Baikalides; Mongolides;
Northern Circum-Pacific; Oroclinal and strike-slip tectonics』
1. Introduction
2. Methodology
3. Cratons and Paleo-Mesoproterozoic metamorphic terranes
4. Central Asia supercollage
4.1. Baikalides and Timanides
4.2. Uralides and Altaids
4.2.1. Uralides
4.2.2. Altaids
4.3. Mongolides
5. Northern Circum-Pacific
5.1. Kolyma-Alaska
5.2. Nipponides
5.3. Kamchatka
6. Geodynamic evolution
6.1. Paleomagnetic and paleontological constraints
6.2. Lithological and kinematic constraints
6.3. Plate tectonic reconstructions
7. Conclusions
Acknowledgements
References