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2006 Special Symposia
Friday 24th November, 2006
The NEIL W. ARCHBOLD MEMORIAL SYMPOSIUM was held in honour of
the late Neil Archbold, Professor of Palaeontology, Deakin
University, and Immediate Past President of The Royal Society
of Victoria
Professor Archbold (14th August 1950 - 28th November 2005) was an eminent Australian palaeontologist who specialised in Permian brachiopods. He died in Mendoza, Argentina, following his participation in Gondwana 12 - the Twelfth International Gondwana Congress.
This Memorial Symposium will provide an opportunity for colleagues and friends to honour and celebrate Professor Archbold's life and work by attending the Symposium and/or contributing Symposium papers which will be published as a special issue of The Proceedings of The Royal Society of Victoria (a peer reviewed and internationally circulated journal). A conference brochure with registration details is currently being prepared and will be included in the September Newsletter.
Thursday 26th October, 2006 at 7pm
Speaker: Alan S Finkel
PhD AM
Topic: AN ENGINEER’S INSIGHT INTO THE ELECTRICAL ACTIVITY OF THE BRAIN
J.E. Cummins OBE Memorial Oration.
Rapid communication between cells in the brain and the peripheral nervous system is mediated by electrical signals. Like pulses in a telephone line, these signals have specialised responsibilities and actions, but unlike their telephonic counterparts that transmit electrical signals by the flow of electrons, signals in brain cells are carried by chemicals that flow through protein trapdoors called ion channels. In his Oration Dr. Finkel will describe the key technologies that he and others have developed during the last 25 years to enable the extraordinarily small currents that flow in ion channels to be measured for the elucidation of mechanisms of operation in health and disease, and for the testing of new medicines.
Thursday 31st August, 2006 at 7pm
Speaker: Professor Kevin O'Connor
Faculty of Architecture, University of Melbourne
Topic: MELBOURNE'S PAST, MELBOURNE'S FUTURE; USING PAST OUTCOMES TO SHAPE OUR FUTURE
Melbourne's historical experience has created an opportunity to influence and direct its future shape and organization. This opportunity emerges from the way that suburbanisation occurred. Suburbanisation was felt first as housing followed the rail net. Later, commercial and community facilities filled in the green-field sites left between the rail lines. The paper will review this history and show that its outcome has constrained the development of major centres in the suburbs. In their place it has created overlapping networks of many activities that tie local parts of the suburbs together. The paper will argue that there are in effect five Melbournes that co-exit and interrelate with one another yet retain their own strong regional character. Rather than attempting to create centres (as in the current strategy), this suburban regional structure could be used to implement policy. This outcome would involve the coordination of Government services, especially transport, in accord with underlying commercial and community links. That would be an effective way of addressing the complex issues involved in urban policy as the regional framework will connect current and future trends to a well established historical context.
29 June 2006
Dr H.J. Harrington, FRSV, F.Geol, Soc Aust
Former Member of The Bureau of Mineral Resources, Geology and Geophysics
"THE ZEALANDIA OROGEN, A NEW UNIT
IN THE TASMAN OROGENIC SYSTEM"
About a third of the Tasman Orogenic System was detached from Australia and moved into the Pacific when the Tasman Sea opened. The detached part is now a subcontinent that is emergent in New Zealand and New Caledonia, but submerged in Lord Howe Rise, Norfolk Ridge, Campbell Plateau and Chatham Rise. Those regions have been given the collective name Zealandia in several recent publications. Zealandia includes Exclusive Economic Zones of France, Australia and New Zealand and therefore seismic and magnetic traverses have been made in them and have increased the knowledge of their Cretaceous and Cenozoic sediments, but not of the underwater pre-Cretaceous pre-separation rocks. This paper attempts for the first time to reconstruct those pre-separation zones and show them on a map. (Cretaceous volcanic and plutonic rocks form a huge magmatic belt in the western part of Zealandia, but to keep to the main story they are only briefly mentioned, as are the lines of Cenozoic volcanos in the Tasman Sea.)
The Tuhua Orogen forms a western part of New Zealand and extends into Lord Howe Rise and southern Campbell Plateau. It consists of Cambrian, Ordovician, Silurian and Early Devonian rocks that are regarded as southern extensions of the Stawell and Bendigo Zones of Victoria, and possibly part of the Melbourne Zone. There is likely to be strong debate about the writer’s answer to the question “How did the Tuhua Province get out there with Tasmania and South Tasman Rise in the way?” (The answer is “by eastward movement of Tasmania and the Tuhua Orogen”).
The central and largest region of Zealandia is here termed the Tasmantis Orogen, and it is argued that it is a volcanic island arc complex of Carboniferous to Early Triassic age. It might go back to the Late Devonian. It is exposed in New Zealand, Queensland and New Caledonia and consists of three Zones which were originally an active arc, an interarc basin and a passive arc. These three longitudinal zones can be given the names Brook Street – Highbury Zone, Maitai-Murihiku Basin, and Dun Mountain-Caples Zone. For many years they have been described as separate tectonically displaced “terranes” but are here united in one island arc system that became an orogen attached to Australia. Most of it was removed again in the Late Cretaceous when the Tasman Sea opened. A part of the orogen is still in Australia in the Gympie Province. It is argued that the Gympie Province is much more extensive and partly older than previously recognised and that it extends for 400 km northwards from Brisbane to near Gladstone, and extends inland from the coast to the Esk Trough. The eastern edge of the Esk Trough is on or near an unnamed Late Carboniferous continental truncation zone that became an Early to Mid Triassic accreation zone (see below). The Tasmantis Orogen provides an unusual opportunity to study the eroded interior of a volcanic island arc system that is well exposed on land. It must have formed a fair way out in the Pacific because no Permian glacigene sediments have been recognised in it.
The eastern region of Zealandia includes the pile of Torlesse rocks that makes up a large part of the Southern Alps in New Zealand. There is active debate and a large literature about whether that pile was derived from Australian orogens or Antarctica, or even South America. It is argued here that the pile was derived in large part from an unexpected source, the Sydney-Bowen Basin, which was eroded in the late Mid and Late Triassic after the docking of the Tasmantis Orogen. About 4 to 5 km of the Sydney-Bowen Basin and its equivalents were eroded in the Mid and Late Triassic down to high-rank coals that are now being mined from open pits at the surface. The coal measures were then covered from the latest Triassic by the thinner Surat and Great Artesian Basins.
The map of Zealandia seems to show that parts of the New England and Lachlan-Tuhua orogens were removed from Greater Australia in the Late Carboniferous along a truncation line or truncation zone and are now in some place unidentified (perhaps in Asia). The truncation line or zone in New Zealand is the Median Tectonic Line (MTL or Fyfe’s Line). In New Zealand it is almost everywhere hidden under younger rocks but has been the subject of many studies. In Australia the zone is better exposed along the two margins of the Esk Trough in S.E. Queensland but it has no name and has been studied very little because its significance has not been recognised. In the Permian it became a passive continental margin in eastern Australia, and presumably a continental terrace was built outwards from it during the 55 million years of the Permian and Early Triassic and is now exposed on the sides of the Esk Trough. After the addition of that terrace it became an accretion suture in the Early and Mid-Triassic when the Tasmantis Orogen docked with the Australian continent and became an integral part of it and of the Tasman Orogenic System.
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