Sir Douglas Mawson solved a real Red Centre mystery

Douglas Mawson.
Douglas Mawson.

MENTION the name Sir Douglas Mawson and the ice-shelves of Antarctica clamber to mind.

A trained geologist, Mawson earned his fame as an Antarctic explorer, beginning with the British Antarctic Expedition of 1907-1909, led by (Sir) Ernest Shackleton.

Travelling by three-man sledge, Mawson journeyed to the south Magnetic Pole, and during the same period became among the first to climb Mount Erebus.

He visited again during 1911-14 on the Australasian Antarctic Expedition, when he was forced by circumstance to walk 160km alone dragging geological specimens behind him on a sled, the only man to survive that particular outing.

Undaunted, in 1929-31 he returned to Antarctica to map its coastline, and to this day Mawson's hut at Cape Denison - where he survived two brisk winters - still stands, although the hut's deteriorating condition is now cause for concern.

Mawson was born in Yorkshire, England in 1882, but the family migrated in 1884 and settled in Rooty Hill, near Sydney.

Later he attended Fort Street Model School, and by 16 had enrolled to study mining engineering at Sydney University.

A lifelong interest in scientific exploration began as a new graduate with a trip in to the dense jungles of Vanuatu to map the geology of the New Hebrides.

Mawson was knighted in 1914 and served in a scientific capacity during the First World War, after which he returned to the University of Adelaide, where in 1921 he was appointed Professor of Geology. These days Mawson is best remembered for the Australian Antarctic Base that bears his name, and for his portrait - unshaven and wearing full balaclava - on the Australian $100 note, in circulation between 1984 and 1991.

Much less widely known, however, is Mawson's role in Central Australia, which was pivotal to modern understandings of the geology of the Centre's magnificent MacDonnell Ranges.

In fact, Mawson's adventures in the Centre are a detective story in their own right. For the only clue in Mawson's geological "whodunit” was a fossil algae, found hundreds of kilometres to the south.

How did it relate to the evolution of the MacDonnell Ranges? Mawson visited the region in 1927 to find out.

He travelled in the company of geologist and explorer Cecil Madigan, later author of Crossing the Dead Heart, a recounting of his traversal of the Simpson Desert by camel.

Together, Mawson and Madigan travelled by motor car from Alice Springs to Glen Helen to inspect some limestone there.

They followed what was, at the time, the only road west, Glen Helen and Mission Station being the only two places under settler occupation between Alice Springs and Western Australia.

Understandably, maps of the day weren't too flash.

Madigan reports only two maps were available, both incomplete, and being compiled of data from the Horn Expedition of 1894 and its leader Charles Winnecke, and earlier work by Charles Chewings and even Ernest Giles. Madigan described both documents as "poorly printed, with frequent gaps in lettering and lines”.

As an aside, Madigan reports that around the time of writing the Royal Australian Air Force was searching for airmen gone missing to the west of Alice Springs, a venture which brought some complaint about the maps from the "lost aviators and of a prospecting party and their searchers” (1).

Searching for the fossil algae in 1927, Mawson and Madigan followed the horse and stock track to Glen Helen, the first to do so by motor car.

Of the trip, Madigan offered this advice: "I do not advise anyone else to attempt it.”

Nonetheless, the pair made it there and back in five days, hurriedly scribbling notes from their observations.

While Madigan would later undertake further reconnaissance of the western region by air and camel, Mawson wrote up his own findings on the geology, published in 1930 jointly under both names in the Quarterly Journal of the Geological Society.

Prior to the work of Mawson and Madigan, rocks underlying Alice Springs and the MacDonnell Ranges (and chiefly of interest to Mawson) had been described as being of ages described by geologists as pre-Cambrian, Cambrian, or Ordovician.

Interpreting these terms is simple enough. Pre-Cambrian is older than 540 million years (but less than the age of the earth at some 4.5 billion years). Cambrian is between 490 and 540 million years old, and Ordovician is the youngest, between 445 and 489 million years old.

There was confusion over whether some rock beds near Alice Springs were Ordovician or older; as Mawson points out: "Geologists had expressed diverse views on the matter.”

Already in the MacDonnell Ranges, Charles Chewings had discovered fossils of small animals usually only found in moist environments, such as wet soil or decomposing tree bark.

The fossils helped date the rock surrounding, and, in combination with work from other regions, suggested a date older than the previously proposed Ordovician.

When similar fossils were discovered in the Flinders Ranges of South Australia in 1924, in rocks thought much older, the more recent date for the Central Australian beds came under serious doubt.

Mawson's curiosity was piqued.

By motor car to Glen Helen and during short fossicking expeditions on foot, Mawson and Madigan kept a weather eye for fossils.

As it turns out, they found plenty, certainly enough to reshape the thinking on Red Centre geology.

The rocks they observed contained fossil algae on "an immense and striking scale”, and, along with other clues, provided the pair with a firmer basis for dating the rock.

Mawson exhibited the rocks at the Royal Society of London in 1928, and later, by virtue of further field work in the Flinders Ranges, he published his findings.

Mawson (and Madigan's) ideas were swiftly adopted by other geologists and the stage set for a modern understanding of the many-layered geology of the MacDonnell Ranges.

Algae and a hunch had taken the polar explorer from Adelaide to the Centre and to London and back again.

But he had his answer.

1. Madigan's paper, The Physiography of the Western MacDonnell Ranges, Central Australia, aimed to rectify the mapping situation, and is interesting as a landmark document for this alone. The work was the culmination of three trips made by Madigan into the region, including the one with Mawson in 1927.

Topics:  geology

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