The paper reviews previous and recently obtained geological,stratigraphic and geochronological data on the Russian-Kazakh Altai orogen,which is located in the western Central Asian Otogenic Belt(CAOB),between the Kazakhstan and Siberian continental blocks.The Russian-Kazakh Altai is a typical Pacific-type orogen,which represents a collage of oceanic,accretionary,fore-arc,island-arc and continental margin terranes of different ages separated by strike-slip faults and thrusts.Evidence for this comes from key indicative rock associations,such as boninite-and turbidite(graywacke)-bearing volcanogenic-sedimentary units,accreted pelagic chert,oceanic islands and plateaus,MORB-OIB-protolith blueschists.The three major tectonic domains of the Russian-Kazakh Altai are:(1) Altai-Mongolian terrane(AMT);(2) subduction-accretionary(Rudny Altai,Corny Altai) and collisional(Kalba-Narym) terranes;(3) Kurai,Charysh-Terekta,North-East,Irtysh and Char suture-shear zones(SSZ).The evolution of this orogen proceeded in five major stages:(i) late Neoproterozoic-early Paleozoic subduction-accretion in the Paleo-Asian Ocean:(ii) Ordovician-Silurian passive margin;(iii) Devonian-Carboniferous active margin and collision of AMT with the Siberian continent;(iv) late Paleozoic closure of the PAO and coeval collisional magmatism;(v) Mesozoic post-collisional deformation and anarogenic magmatism,which created the modern structural collage of the RussianKazakh Altai orogen.The major still unsolved problem of Altai geology is origin of the Altai-Mongolian terrane(continental versus active margin),age of Altai basement,proportion of juvenile and recycled crust and origin of the middle Paleozoic units of the Gorny Altai and Rudny Altai terranes.
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