Geography Reference
In-Depth Information
Sanmartín and Ronquist (2004) provided a recent synthesis of ideas
concerning the fragmentation of Gondwana, which they presented as a geo-
assic (165-150 mya), when rifting began between India and Australia-east
Antarctica. Shortly after, the Madagascar-India block, which was adjacent
to Somalia, broke away from Africa and began moving southeast, attain-
ing its present position in the Early Cretaceous (121 mya). India separ-
ated from Madagascar in the Late Cretaceous (88-84 mya), with the open-
ing of the Mascarene Basin, and began drifting north, eventually to col-
lide with Asia about 50 mya. South America began to separate from Africa
in the Early Cretaceous (135 mya), with the opening of the South Atlantic
Ocean at the latitude of Argentina and Chile. Northern South America and
Africa remained connected until the mid-Late Cretaceous (110-95 mya),
when a transform fault opened between Brazil and Guinea. As a result,
Africa started drifting northeast and collided with Eurasia in the Paleocene
(60 mya), whereas southern South America drifted southeast into contact
with Antarctica. New Zealand, Australia, South America, and Antarctica re-
mained connected until the Late Cretaceous: East Antarctica was adjacent
to southern Australia, whereas New Zealand and southern South America
