A keystone in a changing world - Antarctica: Global Science from a Frozen Continent - page 47

Figure 2.14 A continental reconstruction for a supercontinent named Rodinia showing
how East Antarctica (EAT) was most likely joined to North America (LAR) 750million years ago.
(Credit: Ian Dalziel)

scattered nunataks that protrude through the East Antarctic ice sheet.
Subduction of proto-Paci floor was also taking place along the length of

the Transantarctic Mountains at this time, forming many of the rocks that we see
today spectacularly exposed in the uplifted mountain range.

c ocean

Antarctica: a keystone of ancient Gondwana

For the 300million years of its history, Gondwana did not remain in a xed

position, but wandered from a more equatorial position southwards to a more polar
position as the supercontinent started to disintegrate. It migrated through different
climatic regions and was colonised by an evolving flora and fauna.

first part of its journey, picture a continent traversed by large
meandering river systems and partly covered in lakes and shallow seas inhabited
by armour-plated

For the

fish, now preserved as fossils in sedimentary rocks along the
length of the Transantarctic Mountains. Inevitably, climatic conditions changed
dramatically and just as the present continent is covered in ice, so too was the