Journal and Proceedings of
The Royal Society of New South Wales
Volume 124 Parts 1-2 and 3-4 [Published Dec 1991]
CONTENTS
| AUTHORS & TITLES | PAGES |
| Parts 1-2 | |
| Bhathal, R. Henry Chamberlain Russell: - Astronomer, Meteorologist, and Scientific Entrepreneur | 1 |
| Coenraads, Robert R., Paige,Simon,C.B., and Sutherland, F.Lin. Ilmenite-mantled Crystals from the Uralla District, New South Wales. | 23 |
| Loughnan, F.C.. Permian Climate of the Sydney Basin - Cold or Hot? | 35 |
| Flannery, Tim. The Impact of Humans Upon the Biota of Australasia. (Report by G.W.K.Ford) | 41 |
| Parts 3-4 | |
| Ford, G.W,K.. Fire from Heaven - Proton Power:- Past, Present and Prospective (Presidential Address 1991) | 47 |
v124 pts 3-4, pp.1-21
Henry Chamberlain Russell:- 19th Century Astronomer, Meteorologist and Organizer of Australian Science
R. Bhathal
Abstract. The life and work of Henry Chamberlain Russell spanned a key phase in the development of science in Australia. It was a time of transition - from a colonial to an independent period of science. H. C. Russell was an influential figure in this development. He was responsible for some of the major physical science programs that were undertaken in 19th century Australia, some of which were internationally of high importance. This paper examines Russell's scientific work in l9th century colonial Australia.
v124 pts 3-4, pp.23-34
Ilmenite-Mantled Rutile Crystals from the Uralla District, New South Wales
Robert R. Coenraads, Simon C.B. Paige and F. Lin Sutherland
Abstract. Ilmenite-mantled ruti1e crystals of enigmatic origin arc found in Late Tertiary conglomeratic arkoses and Quaternary alluvium in thc vicinity of Uralla, New South Wales. They comprise homogeneous, single, rutile crystal cores with ilmenite replacing the crystals and penetrating along (100) planes. The ilmenite ranges from higher TiO2 adjacent to the rutile core to higher FeO at the outer edge. MgO decreases away from the core. This is consistent with reaction in a magma containing iron but poor in magnesium. The crystals are not associated with any obvious parent rock type. Comparisons of the chemistry of the ilmenites with a wide range of known ilmenite associations indicate that the source rock is unlikely to be mafic or ultramafic and that they are an unlikely to be an indicator for diamond source rocks. The minerals may have formed as late-stage or cavity crystallizations from fractionated felsic magmas before eruption.
v124 pts 3-4, pp.35-40
Permian Climate of the Sydney Basin - Cold or Hot?
F.C. Loughnan
Abstract. The concept of a frigid to glacial climate prevailing in the Sydney Basin throughout most of the Permian has received general acceptance. Yet, on the basis of mineral composition of the strata, this conclusion is difficult to substantiate. Indeed, from the evidence available it would appear more likely that humid, warm to hot conditions, favourable for the development of kaolinite and in part bauxitic clayrocks, persisted at least intermittently from the earliest Permian through almost to the Middle Jurassic,
v124 pts 3-4, pp.41-43
The Impact of Humans upon the Biota of Australasia
Tim Flannery
The following is a summary of an address delivered by Dr. T.F. Flannery before the Royal Society of New South Wales on Wednesday 3rd July 1991 at the Australian Museum. (Prepared by Dr G.N.K. Ford, Vice-President, from a tape-recording of the address: Dr.Flannery kindly reviewed and corrected the text, and provided the list of 'Further Reading')
The Society was especially pleased to hear from one of its Medallists: Dr Flannery, who is the Head of the Mammal Section, Division of Vertebrate Science, The Australian Museum, was awarded the Society's Edgeworth David Medal in March l991 for his outstanding contributions in the field of mammal studies.
Australia's last c.40,000 years has been a period of great changes, probably coinciding with the arrivals of humans in the region. Quite early in this period, perhaps during only the first few l000 years, all the large mammals of over 1000 kilograms (4 species) became extinct, and also all mammals over 100 kg (15 sp.) also became extinct. In the 10 to 100 kg range, some survived (humans fall in this range). Below 10 kg, none of the mammals became extinct in the earlier part of the period, but were affected in the most recent times. Reptiles were also affected, for example a giant snake, 6m long & weighing 100 kg, and giant goannas and land-based crocodiles. Many of these reptilian species were carnivores and major predators on the mammals. The largest mammalian carnivore on the Australian continent at any time was the human being. This has been a unique situation compared with other continents.
The cause of extinctions is subject to much debate: Dr Flannery's personal view is that there have not been climatic changes on the Australian continent during this period such as could have caused extinctions, and that the major cause on this continent was hunting by humans. Many of the animals were large and slow moving, so readily hunted. They had no large warm- blooded predators, and were not prepared for the human onslaught. There were no large warm-blooded carnivores because the Australian environment was relatively resource-poor and hence impoverished as regards food-sources. The impact of humans was very profound since they took for themselves a very large share of the available energy budget.
Following the initial big decline in large mammal species during the first few thousand years after the arrival of humans, there was little change in the residual population of small mammals until the arrival of Europeans 200 years ago. A new phase of extinctions then commenced, which has resulted in the extinction of 23 species of medium-size mammals and one bird. This is a very strange extinction event: excepting the Thylacine, all of them were the common animals in the range l00 grams to 5 kilograms, almost all mammals, and all living in the drier parts of Australia. Half of these were rodents, one of the most successful orders of mammals alive on Earth today. Researches in NW Australia, where there has never been a significant impact of European imported rabbits, foxes, sheep and cattle, indicate that the prime cause was probably the removal of Aboriginal people from the landscape, This changed the fire regime from one in which small patches were burnt regularly to the more recent situation in which large areas are burnt at one time, consequent on prolonged periods of fuel build-up followed by large natural fires.
The medium-sized animals left in the large burned areas could not migrate to unburnt areas to find food and became victims of wide-ranging predators such as quolls and wedge-tailed eagles and, later, foxes. The larger mammals could escape to other areas, and the residual very small animals could survive in the small un-burnt patches which usually remain after a fire. Dr Flannery believes that this small-patch fire regime mimicked the effect of the 60 species of large herbivores which existed before the arrival of the Aborigines. The fossil record appears to confirm this concept. Examples of these recently extinct medium-sized mammals include the Eastern Hare Wallaby, the Desert Rat-kangaroo, & the Broad-faced Potoroo. Today, in much of the arid and semi-arid country there is not a single middle-sized mammal to be found: nothing between a rat and a Red Kangaroo: only their bones remain. Fossils indicate a rich fauna in these areas before the arrival of humans.
Dr Flannery then reviewed the very different situation in New Guinea. Here there were very few large mammals. Only 3 species weighed more than 100 kilograms, and only 7 were between 10 and 100 kilos. Of these some six species became extinct many tens of thousands of years ago, probab1y soon after the arrival of humans. The two regions have basically the same fauna, but differ greatly in regard to terrain and in biomass available to support animals. New Guinea is a very hostile environment for large mammals, including humans, due to the mountainous and rain-forested terrain. In the last ten thousand years or so agriculture developed, coinciding with the local extinction of several more mammals, including species of fruit bat; and two thousand years ago the dog was introduced and commenced a very large predation on the mammals, especially the wallaby (Thylogale). Today the several species of Tree-kangaroo are under intense threat from human hunting activity. This is on account both of the big increases in human population due to improved food supplies and medical care, resulting in the tripling of the population in some areas in the last fifty years, and because people can now hunt anywhere despite the difficulties of terrain and forestation.
Dr Flannery then reviewed extinctions in other parts of the Pacific. The arrival of humans in New Zealand only around 1000 years ago had a catastrophic effect on the fauna. All 12 species of Moa, about 30 other species of birds including swans, ravens, geese and even small birds became extinct. Also large frogs, large insects, geckoes, tuataras and others. It seems probable that changes in forest structure and in fire regimes over the period of human habitation must also have contributed to the extinction processes.
Timor lost its 12 species of the world's biggest rats some 5000 years ago. The Philippines and the Solomons also lost their giant rats, mostly due to forest destruction. Some such rats are known to have had femur bones as much as a centimetre thick, and may have been a metre long. Some forest-dwelling rats construct large nests, similar to those of birds of prey, in large trees, which makes them very vulnerable to the destruction of forests by humans. Christmas Island was untouched until about 1880, but unfortunately for the fauna phosphate was discovered; the native rats were probably destroyed by diseases imported with European rats.
Returning to Australia and the present times, recently the Orange Roughy was discovered as a fishing resource. These 12 inch long fish, which take 100 years to grow to adult size, are being dredged in enormous numbers from a kilometre depth on the continental shelf off south-east Australia, using sophisticated modern equipment, and then sold for a mere $9 to $12 per kilogram as "Ocean Perch". They are being harvested at a rate far too high for the population to replace itself and the species may well be doomed to ' commercial extinction' .
Almost every Australian fishery has been subjected to the same process. Australian coastal waters are very nutrient-poor: we have not got any great fisheries as in the North Atlantic or South American coasts. In the Great Barrier Reef fish are being taken at 12,000 tonnes per year and is the cause of great problems.
Australia is a very large land-mass: 7.6 million square kilometres, with only l7 million people. But Australia is by far the most resource-poor of the continents. The seas surrounding Australia are basically biological deserts. There is tremendous species diversity, but very little productivity. The average levels of nutrients (nitrates and phosphates) in Australian soils is about half those of soils overseas. We also have a very erratic climate, basically dominated by the ENSO cycle, as no other continent. Hence this is a land of rain and flood and then long periodic droughts, on about a 10 or 15 year cycle. The soils in Australia are very thin and infertile compared with those of other continents. We have some 77 million hectares of arable land in Australia, but all of it is marginal on a world scale; of that, we have used about 30%, of which some 60% is suffering serious degradation. Evidently the amount Australians are taking out of national productivity is disproportionately large.
Although there are only l7 million people living on this continent, we have one of the highest standards of living in the world, and we depend on exports to support this level. We also have the most rapid rate of population growth in the Western World . These three factors combine to form a recipe for disaster: the poorest continent on Earth, the most rapid rate of population growth and one of the highest standards of living in the World. These three factors are pushing us to use resources quite beyond a level we which we should never even approach. We are using natural resources far faster than they can replace themselves.
We are not the first people on Earth to exploit to excess a limited resource base: there are many examples all over the World from all epochs of history of peoples which have done this and eventually run into serious problems. One small-scale example is Easter Island, which was probably discovered by Polynesian explorers about 1400 years ago, as evidenced by sediments in a crater lake on the Island. It was covered by forest, inc1uding endemic palms and perhaps endemic birds: an island paradise. The people thrived for some 700 years. The Island was discovered by Dutch explorers in 1722. The huge statues facing inland demonstrate that there must have been timber available for rollers to move the huge stones; wood was used for sea-going canoes. Some 100 years later visiting Europeans found a breakdown of social order, particularly the taboo system for reserving resources for particular needs; there was no more wood and there was serious starvation. The population rapidly declined to about 160 survivors from tens of thousands.
In poetry Shelley's 'Osymandias' provides an example of places all around the Mediterranean which once supported great cities but which now lie in the middle of deserts; similar events have occurred in the south-west of the United States and in the Middle East. All these places share horrifying similarities with the Australian landscape, and the pattern of the extinctions we have seen in those areas are very similar to those seen in Australia. The big fauna disappears in the Pleistocene sometime, people get in and develop agriculture and suppress the remaining carnivores, they apply irrigation to fragile soils, and eventually exceed the ability of the environment to sustain them. The terrifying thing is that those areas have never recovered: there is still desert in those areas which were overexploited as much as 2000 years ago.
There is not a lot of optimism for the situation in Australia and in the southwest Pacific in general, simply because of the growth in human numbers. Maintenance of our current (world) fertility of 3.8 children per family would result, by 2100, in 50 million [sic: read 'billion'] people on Earth. It seems unlikely that resources will be sufficient to support 10 times the present population. If we reduce our fertility to an average of 3 children per family, even in that case we should have 20 million [sic] people on Earth in 110 years time: 4 people for every one now, which also seems hardly feasible. At replacement fertility the Earth's population might grow to 6 billion and then remain steady. This might enable us to deal with our resource and other problems. But we still seem to want to keep going as before.
- Further Reading
- Burbridge, A., Fuller,P., Johnson, K. and Southgate, R. 1987. Vanishing desert dwellers. Landscape 2, 7-12
- Burbrige, A.A., Johnson, K.A., Fuller, P.J. and Southgate, R.I. 1988. Aboriginal knowledge of the mammals of the central deserts of Australia. Australian Wildlife Research 15, 9-39.
- Burbridge, A.A. and McKenzie, N.L. 1989. Patterns in the modern decline of Western Australia's vertebrate fauna: causes and conservation implications. Biological Conservation 50, 143-198.
- Flannery, T. F. 1989. Plague in the Pacific: a new perspective on the last 40,000 years. Australian Natural History 23, 20-29.
- Flannery, T.F. 1989. Who killed Kirlipi? Australian Natural History 23, 234-242.
- Flannery, T.F. 1990. Pleistocene faunal loss: implications of the aftershock for Australia's past and future. Archaeology in Oceania 25, 45-67.
OZYMANDIAS of EGYPT Percy Bysshe Shelley (1792 - 1822) I met a traveller from an antique land Who said: "Two vast and trunkless legs of stone Stand in the desert. Near them on the sand, Half sunk, a shattered visage lies, whose frown And wrinkled lip and sneer of cold command Tell that its sculptor well those passions read Which yet survive, stamped on these lifeless things, The hand that mocked them and the heart that fed; And on the pedestal these words appear: My name is Ozymandias, king of kings; Look on my works, ye mighty, and despair!' Nothing beside remains. Round the decay Of that colossal wreck, boundless and bare, The lone and level sands stretch far away."
v124 pts 3-4, pp.47-69
Fire from Heaven Proton Power:- Past, Present and Perspective
G.W.K. Ford
(Presidential Address 1991)
Proton Power energises and materialises the Universe. The Address attempted to illustrate this general concept with a leavening of Ancient Greek Cosmogony and a Theogony of Olympic Gods, a few monochrome versions of various works of art, and brief extracts from the writings of Aeschylus, Milton, Virgil & other poets. Although many entities in science derive their names from classical sources, the relating of selected events in mythology to modern interpretations of cosmic and sub-atomic processes is obviously contrived and only intended to entertain and to aid the memory! It was hoped, however, that this treatment would also serve as a token of the broad scope of the Society's interests by mixing together Science (at an elementary level), with Art, Literature and Philosophy, (albeit at a superficial level), having the particular aim of interesting our non-scientist Members & Associates, as well as those specialist in various sciences outside, in this case, the worlds of nuclear physics, cosmogony and nuclear engineering.
The main thesis of the lecture was the essential role of the proton in the original creation, the formation and heating of stars, the synthesis of all the chemical elements, the supply of radiant energy to the Earth's surface and the heating of the Earth's crust, thus facilitating continental drift, mountain building & weather, and hence soil formation and the support of plant and animal life. Mankind is able to employ proton-based nuclear fission & fusion reactions to provide small-scale local heat sources and explosions.