The geology of Mawson

Most of the exposed rock around Mawson including the Framnes mountains were formed in the Precambrian era (4600 – 520 million years before present day) which predates vertebrate life forms.

Antarctica formed part of Gondwana which split from Africa, South America, Australia and India. The geology around Mawson is very similar to the Eastern Ghats province of India. 

Most of the rock was formed by molten magma that pooled from fifteen kilometers below the surface cooling slowly forming large crystals into what is now called Mawson Charnockite which contains the relatively rare mineral sapphrine. Charnockite is characteristically dark brown, hard and brittle and forms high peaks and sharp ridges. 

Metasediments formed by mud and calcareous sediments pushed at least twenty five kilometers below the surface also make up a smaller portion of the regions geology. The Metasediments are often banded and contain garnet, biotite, feldspar and quartz.

 

Mawson Charnockite

Metasediments