Douglas Mawson in the desert

Today, 5 May, is the birthday of Sir Douglas Mawson, the Australian geologist best known for his Antarctic explorations. He undertook multiple expeditions to the frozen south, including leading the Australasian Antarctic Expedition of 1911–14, which was not just geared towards exploration but also scientific research.

But Mawson’s long career wasn’t entirely focused on the polar regions. Cosmos chatted to Mark Pharoah, Senior Collections Manager at the South Australian Museum, to find out what we know about Mawson’s research closer to home.

Into the outback

One reason Mawson was so interested in visiting Antarctica was his intense interest in the geology of South Australia. In 1905, at the tender age of 22, he took up a lecturing position in mineralogy and petrology at the University of Adelaide and began to roam the state using a free rail pass, given to him by the government for geological investigations.

Within two years of arriving, he’d visited the Adelaide Hills, Kangaroo Island, the Flinders Ranges, the southern Yorke and Eyre peninsulas and the Olary-Broken Hill area.

He was particularly drawn to the outback regions of northern SA, according to Pharoah, which he returned to over the coming decades, filling dozens of diaries with notes.

Pharoah explains that while Mawson’s Antarctic diaries are well-known, the museum and its volunteers have also been trawling through and transcribing the journals detailing his field trips into regional South Australia.

Interestingly, they reveal that these trips mirror Mawson’s major expeditions to the Antarctic in many ways.

“He was using the same clothing and equipment to keep warm,” Pharoah says.

The Australian desert can get very cold, as anyone who has been out at night in winter in the outback would know. Antarctica is also essentially a very cold desert, with very little precipitation.

“Mawson was, in a sense, encountering at the extreme these two types of deserts, and trying to make sense of this world and also survive – and at times lead quite large groups of people,” Pharaoh says.

Mawson would often take groups of university students on field trips, and the logistics of food and transport would have been challenging.

Pharoah notes: “In some ways, the Antarctic is this interesting contradiction, because although it’s a very tough and unforgiving environment, the men were going down and sometimes enjoying quite a luxurious life with exotic foodstuffs that were donated to the expedition, and there were quite nice wines drunk.

“So it’s an interesting contrast of extremes. Everyone thinks of the hardship but there were moments of luxury as well. I don’t think anything like that could be described when Mawson was in the outback. There were no luxuries – it was all pretty mundane and arduous and hot or cold.”

Glacial links

Australia and Antarctica mirror each other in more ways than one.

“The South Australian landscape is filled with evidence of past glacial activity, which is part of what made Mawson interested in trying to put the pieces together,” Pharoah explains.

In his pre-Antarctica days, at 24 years of age, Mawson spent several weeks exploring the Olary-Broken Hill area by horse and motorbike. In this remote and semi-arid place, he discovered formations made up of masses of boulders and debris left behind from an ancient ice age that engulfed most of the Earth. He wrote: “I was face to face with a great accumulation of glacial sediments of the Precambrian Age, the greatest thing of its kind recorded anywhere in the world.”

From these outback hills, Mawson was drawn to the great frozen south – because he wanted to meet a real-life glacier: “I desired to see an ice age in being.”

By studying how Antarctic glaciers move and deposit sediment, he gained a better idea of how the sedimentary glacial rocks formed in South Australia millions of years ago.

In fact, hundreds of millions of years ago, Australia and Antarctica were joined as part of the supercontinent Gondwana. They still share many geological features – although Mawson’s early interest in SA’s glacial geology predates the idea of continental drift or plate tectonics.

Radioactive rocks

Mawson’s early Antarctic expeditions were driven both by scientific interest and an interest in discovering untapped resources like rare earth minerals – partially to fund the prohibitively expensive missions.

“He always had an eye for commercial geology,” Pharoah says. “A lot of academic geologists in Australia would [have], because it was a potential way of making money that would be far greater than their modest salaries.”

In a similar way, Mawson’s ventures into northern SA were with a purpose – he was on the hunt for radioactive minerals.

Pharoah explains that Mawson had a device called an electroscope, which could detect the presence of an electric charge or ionising radiation, and therefore could measure whether unusual minerals or rocks were radioactive. It helped identify and describe the mineral davidite, which contains the radioactive elements titanium and uranium, in the region known as Radium Hill near Olary.

Traces of radioactive elements were also found near Arkaroola in the northern Flinders Ranges, although they never became commercially viable as mine sites in either case.

Interestingly, it was also radioactivity that drew Mawson’s student, Reg Sprigg, up north in the 1940s. As Sprigg assessed an old mine site in the Ediacara Hills to determine the viability of re-opening, he instead discovered Precambrian fossils – leading geologists to define a new geological period, the Ediacaran, for the first time in over 100 years.

Today, both Antarctica and Arkaroola have a moratorium on mining.

Pharoah is currently working on getting involved in SA’s upcoming Nature Festival, with the idea of creating a trail around Arkaroola that shows exactly where Mawson travelled and studied there, based on deciphering his notes in his diaries.

“They’re quite well-known to be very difficult to follow and hard to read – he’ll say ‘third gate on the right, go past the tree’, and he knew where he was going,” Pharoah says wryly.

Mawson’s love of trees

Somewhat unexpectedly, Mawson also had a great interest in trees.

His wife, Paquita, once wrote that Mawson was happiest when he was planting trees. He was heavily involved in sustainable forestry in the Adelaide Hills and even had a hobby farm employing locals where timber was grown, milled and sold in the years after World War I.

“The focus really was on trying to develop our forestry resources, and part of thinking was to take pressure off our existing endemic forests,” Pharaoh explains.

Mawson gave a university address in 1926 about trees, stressing their value in retaining the very depleted Australian soil.

Pharaoh points out that Mawson’s concern was shared by another prominent South Australian figure, the landscape artist Hans Heysen. In 1920 Mawson and Heysen were both founding members of the South Australian Forest League, which was dedicated to the protection of forest reserves, valuable trees and the fostering of native tree planting.

“It is our duty by replanting to try and regain that Australian character which we have almost lost by thoughtless destruction, and plant trees indigenous to our soils and climate,” Heysen said in a speech in 1939.

Pharaoh says that a definite link between the two men has not been found in diaries, but he wonders if it is still to be revealed.

“It would be lovely to have more of those connections known,” he says. “Sometimes it can be in a person’s family history that is passed down from generation to generation, rather than official documents.”