Sv. Rasskazov, MAGMATISM RELATED TO THE EASTERN SIBERIA RIFT SYSTEM AND THE GEODYNAMICS, Bulletin des centres de recherches exploration-production Elf-Aquitaine, 18(2), 1994, pp. 437-452
Based on the variation in space and time oi the composition of rift-re
lated volcanic rocks in the Trans-Baikal region, the Cenozoic deep-sea
ted processes are shown to be inherited from the tectonic and magmatic
activity during the Mid-Paleozoic to Mesozoic. The Eastern Siberia ri
ft system is divided into three groups of rift basins : the Tunka-Erav
na group with associated volcanics formed in the Late Cretaceous to Mi
d-Cenozoic, and the essentially non-volcanic Baikal-Chara and Khubsugu
l-Darkhat groups which formed during the Late Cenozoic. Although devel
opment oi the Eastern Siberia rift system was contemporaneous with the
Indian-Asian collision, the relative rotation of terranes separated b
y the Baikal-Chara group of rift basins around the pole at its northea
stern termination, indicates that extensional forces were local. A hot
spot model which proposed to explain the geodynamics within the Easte
rn Siberia rift system, implies a powerful heat impulse along the sout
hern edge of the Siberian craton from -29 to -12 My (Late Oligocene to
Miocene). This was expressed by doming, rifting and vigorous mildly a
lkaline basaltic volcanism. A migrating sequence of volcanism within t
he western area of the Khubsugul-Darkhat group might indicate a slow (
0.8-0.9 cm/yr) eastward motion of the Eurasian plate overriding a fixe
d mantle hot plume.