Rocky road from Antarctica to Canberra
Two rocky pieces of the icy continent have arrived in Hobart on the way to a new home in Canberra, where they will go on display as part of a unique outdoor geological museum.
The two boulders of Mawson Charnockite were recently collected near Australia’s Mawson research station and shipped to Hobart on the icebreaker Aurora Australis.
Later in the year, the samples will continue the journey to Canberra to go on display at the National Rock Garden, a collection of unique rock samples gathered from around Australia and its territories.
Mawson Charnockite takes its name from Sir Douglas Mawson, the legendary Australian Antarctic explorer and geologist who mapped large areas of Antarctica and greatly enhanced our knowledge of the frozen continent.
The Australian Antarctic Division’s Chief Scientist, Dr Gwen Fenton, said in addition to the scientific value of the rocks, they would serve as a permanent reminder of Australia’s links to Antarctica.
“The proposal to include a piece of Mawson Charnockite in the National Rock Garden originally came from the late Professor Pat Quilty, who was one of the greats of Australian Antarctic science,” said Dr Fenton.
“He felt a piece of Mawson Charnockite from the Australian Antarctic Territory would be a fitting tribute to not only Sir Douglas Mawson, but also to all scientists who have contributed to our understanding of the continent.”
Professor Quilty was a geologist and palaeontologist who made a large number of research trips to Antarctica, and served as Chief Scientist from 1981 to 1999.
“The rocks are also a reminder of the ancient geological connection between Australia and Antarctica, when the two continents were joined as part of the supercontinent known as Gondwana,” said Dr Fenton.
This type of rock is also found in Western Australia, including near Cape Leeuwin and Cape Naturaliste near Albany, Esperance Bay, Eyre Peninsula, and the Musgrave Ranges.
Originally informally named the Mawson granite, the rock is described as “a brown, gneissic Charnockite with a slight to moderate foliation and numerous xenoliths”.
They are typically composed of quartz, K-feldspar, plagioclase and orthopyroxene, but their exact origin has been a matter of debate amongst geologists.
Once thought to be igneous rocks crystallised from cooled magma, they are now generally considered metamorphic rocks formed by high temperatures and pressures deep below the Earth’s crust.
The rocks were collected under a permit that authorised the rocks to be removed from Antarctica for the purpose of public education via display at the National Rock Garden.