The fragmentation history of East-Gondwana
is divided in five periods, each period being preceded by
mid-oceanic ridge closings and jumps. These plate
movements were controlled by three branches of
convection currents (CC): the western, the central and
the eastern ones. Period 1 began with the rise of
compressional constraints in the Neo-Tethys region
caused by the anticlockwise rotation of East-
Antarctica/Australia as the interaction effect with the
newly formed off-South African E-W CC at M10. This
led to the northward detachment of continental
fragments from Northwest Australia and northeast
India, the creation of an oceanic basin north of India and
the spreading cessation of the Somali Basin at M0.
Period 2 was marked by southward ridge jumps from
the Somali Basin and the north of India. The influence of
the E-W CC ended after the Lower Aptian fan-like
rifting between India and Sri Lanka. From then on, plate
movements occurred in N-S direction and the rotation of
East-Antarctica/Australia got reversed. This period
ended with the fan-like spreading of the Western
Enderby Basin, during which the two arms of the central
CC reunited and East-Antarctica/Australia was
“trapped” within the South Pole Region and rotated
anticlockwise. During Period 3, simultaneous ridge
jumps in Middle Cenomanian conducted to the fan-like
eastward opening of the Eastern Enderby Basin, whereas
rifting activities occurred between Madagascar and
India and between East-Antarctica and Australia. In
Lower Campanian, the oceanic opening between East-
Antarctica and Australia provoked the dispersal of the
Eastern Enderby CC allowing the creation of new
oceanic basins from C33 to C31 and a backward ridge
propagation at C32. Starting from C31, the
northwestward propagating CC underwent sidelong
collisions with the Great Mascarene Basin before setting
between the Seychelles and India where they merged
with the “jumped” Mascarene CC at C29. After the
collision of India against Eurasia in Middle Eocene
(C21), Period 4 was marked by the creation of SEIR, the
connection of CIR with SEIR and the separation of
SWIR from CIR. Northward ridge jumps from SWIR at
C5 generated the East-African Rift system. A pre-
breakup rifting phase started since the Pleistocene in N-S
direction.
Keywords : East-Gondwana; Plate Tectonics; Up-Welling Mantle Convection Currents; Mid-Oceanic Ridges; Oceanic Opening.