The Great Artesian Basin
A wonderful aspect of my analysis of the source of water in the GAB has been the discovery of the writings of J W. Gregory, who was to become Professor of Geology at the University of Melbourne from 1900 to 1904, and then Professor at the
University of Glasgow.
In 1892-3, Gregory led an expedition into British East Africa, studying the Rift Valley and the associated volcanoes, the great lava fields and the geothermal waters. He wrote a book on "The Great Rift Valley" in 1896. He is
credited with naming it the Great Rift Valley, part of which is now called The Gregory Rift.
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He described the Rift as a zone of lateral extension in the earth's crust, and related that to the volcanism, the lava fields and the geysers. This and other work led to him becoming a Fellow of the Royal Society.
Now, Don Anderson, a distinguished geophysicist at Caltech, has just published a paper in which he notes his discovery of a relationship between "Extensional Tectonics" and "Global Volcanism", presenting it as a new
concept. Gregory saw that connection quite clearly a 100 years ago in his work on the Great Rift Valley!
When Gregory was at the University of Melbourne, he took a group of students on a field trip in 1901-02 into the area around Lake Eyre, studying the 'flowing wells of Central Australia". He wrote a book, "The Dead Heart".
Gregory, with his background of understanding of the geology of Africa, America and Europe, immediately sensed that the origin of the waters was plutonic. In his book, published in 1906, he makes some comments that we should still take very
seriously today.
"Plutonic waters are especially important in mining countries, because most of the chief ore-deposits are due to them. And as the deep, water-bearing basin of Central Australia is surrounded on all sides by rocks,
containing rich mineral veins, from the Queensland gold-fields on the east, the Cobar copper-field and Broken Hill in the south, and the Cloncurry gold-field in the west, there is likely to be a considerable amount of plutonic water under Central
Australia.
Its existence appears sometimes to have been altogether overlooked; and the argument, that evaporation would carry off the whole of the rainfall in this district, has been dismissed as obviously impossible, because of the existence of artesian
water.
Where these ascending waters are cut off from the surface by an overlying sheet of clay, they accumulate in any porous beds they can enter, and remain in them subject to high pressure. Any plutonic water rising from the
old rocks of Central Australia would collect in the permeable beds of sandstone beneath the clays. Thence it would rush to the surface, if a bore-hole were made through the water-tight cap above, just as oil
and natural gas escape from the wells of the Caspian and Pennsylvania."
J. W.Gregory in "The Dead Heart Of Australia" 1906
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It is understandable that other people at that time had difficulty in comprehending such a clear statement by Gregory. After all, he was probably the only person in Australia with such a scientific background in the subject. But he must
have influenced the students in his classes.
What is astonishing is the fact that it has taken 100 years for those in charge of the GAB to think again about the origin of the waters, and then only because of my detailed activities in a private capacity. There was even an attempt a year
ago to persuade ATSE not to publish my first paper on the subject.
About 35 years ago I had the opportunity, as an expert, to investigate some very serious civil engineering failures in other countries. At the time I detected a common thread of human factors that lead to the disregard of all evidence or
information that was contrary to the fashionable view.
I recently brought this study up-to-date as a powerpoint presentation, and presented it to an AGM of the local group of the Order of Australia Association, on the general topic of fallacies, fashions and professional responsibility. I took the
presentation to Canberra to the meeting with the GAB technical group, believing that it may assist their understanding. But after my first presentation on the GAB they were not at all interested in any further homily from me, and bolted!