|
|
|
|
Africa, Arabia, India, South America, Antarctica and Australia are
continental blocks resulting from the breakup of the supercontinent, Gondwana, which was
initiated around 150 Ma. Gondwana represents approximately one third of the world's
continental land and contains about 60% of its mineral resources.
The Gondwana assembly:
Gondwana was assembled into a distinct form between 700 and 500 Ma, during the
Neoproterozoic orogenic events, by tectonic accretion of older cratons, island arcs and
oceanic crust relics.
Those cratons are composed of Archean, Paleoproterozoic and Mesoproterozoic terranes, and
are the result of the breakup (at circa 750 Ma) of the former supercontinent of
Mesoproterozoic age called Rodinia (1000Ma).
The Gondwana Paleozoic evolution:
During the Paleozoic, the movement of Gondwana from the Southern pole
Northwards induced the closure of the Rheic Ocean, which separated Gondwana from the
Northern hemisphere's continental blocks (Laurentia, Baltica, Siberia, Kazakhstan, North
China...). The collision of those two continental entities during the Carboniferous, and
the subsequent closure of the Oural during the Permian, led to the formation of a
world-wide supercontinent, Pangea, composed of Gondwana in the South and Laurasia in the
North.
The Gondwana breakup :
Since the Jurassic, the Pangea, and therefore also Gondwana, were
fragmented and began their evolution into the present-day configuration of the continents,
as displayed by the present animation.
|