Journal and Proceedings of
The Royal Society of New South Wales
Volume 110 Parts 3 and 4 [Issued 23 November, 1977]
CONTENTS
| AUTHORS & TITLES | PAGES |
| King, D.S. and Sims, K.P., Occultations observed at Sydney Observatory during 1974-1976 | 81-86 |
| Morgan, T.L., Precise Observations of Minor Planets at Sydney Observatory during 1976 | 87-92 |
| Southwell, I.A. and Maconochie, J.R., The Essential Oil of the Fly-Repellent Shrub, Pterigeron bubakii | 93-94 |
| Dulhunty, J.A., A Bottom Profile across Lake Eyre North, South Australia | 95-98 |
| Hahn-Weinheimer, P and Hirner A., Influence of Hydrothermal Treatment on Physical and Chemical Properties of Chrysotile Asbestos | 99-110 |
| Nashar, B. and Brakel, A.T., Textures of the Carboniferous Ignimbrites in the Hunter Valley, N S.W. | 111-116 |
| Wilkinson, J.K.G., Petrogenetic Aspects of Some Alkali Volcanic Rocks | 117-138 |
| Gorter, J.D., Marsupials from the Douglas Cave, near Stuart Town, New South Wales | 139-145 |
Vol 110 pts 3-4, pp.81-86
Occultations Observed at Sydney Observatory during 1974-1976
D.S. King and K.P. Sims
Abstract. This paper presents the results of occultations observed with the 29 cm telescope during the years 1974-1976.
Vol 110 pts 3-4, pp.87-92
Precise observations of Minor Planets at Sydney Observatory during 1976
T.L. Morgan
Abstract. Positions of 3 Juno, 6 Hebe, 7 Iris, 25 Phocaea, 39 Laetitia, 40 Harmonia and 148 Gallia obtained with the 23 cm telescope are given.
Vol 110 pts 3-4, pp.93-94
The Essential Oil of the Fly-repellent Shrub, Pterigeron bubakii
I.A. Southwell and J.R. Maconochie
Abstract. Steam distillation of Pterigeron bubakii, a shrub used by the Barkly Tableland aborigines as a fly repellent, yielded an essential oil containing β-caryophyllene and p-cymene as major components. Activity tests on the housefly showed no significant repellancy.
Vol 110 pts 3-4, pp.95-98
A Bottom Profile Across Lake Eyre North, South Australia
J. A. Dulhunty
Abstract. A bottom profile constructed from soundings obtained across the northern half of Lake Eyre North, shows cross-sectional features of the Warburton and Kalaweerina Grooves of tectonic origin, and areas termed the Cooper and Neales Depressions believed to have been formed by outwash of estuarine sediments and inshore scouring. Very recent or contemporary tectonic development of the grooves, supports previously recorded evidence of contemporary tectonism.
Vol 110 pts 3-4, pp.99-110
Influence of Hydrothermal Treatment on Physical and Chemical Properties of Chrysotile Asbestos
P. Hahn-Weinhemier and A. Hirner
Abstract. Aqueous suspensions of natural chrysotile fibres of equivalent specific surface area, originating from Advocate, Balangero and Zidani, and synthetic chrysotile were treated hydrothermally at pressures ranging from 1 to 300 kp cm-2 and temperatures from 20 to 250°C for 2 hours to 120 days. The resulting solid and liquid phases were investigated by physical and chemical methods.
The influence of a second mechanical cleaning process and of hydrothermal treatment on structural, chemical and technical properties of the fibres and on the dissolved phase of chrysotile in water are presented. It can be demonstrated that the mechnical qualities of the fibres depend mainly on the constitution of the fibre surface, and to a lesser degree on the amounts of accessory minerals.
Thermodynamic data, as activation energies, activity product constants and Gibbs free energies are calculated and compared with those reported in literature.
Vol 110 pts 3-4, pp.111-116
Textures of the Carboniferous Ignimbrites in the Hunter Valley, N.S.W.
B. Nashar and A.T. Brakel
Abstract, Rocks of the Carboniferous calc-alkaline volcanic series in the Hunter Valley, New South Wales, possess well-defined eutaxitic devitrification and possibly vapour-phase textures and show varying degrees of welding and compaction. The devitrification and vapour-phase textures comprise axiolitic, spherulitic, granular and granophyric forms. The eutaxitic textures suggest that the ignimbrites were emplaced by an ash-flow mechanism with welding commencing after the flow came to rest accompanied by compaction due to the overlying lithostatic load.
Vol 110 pts 3-4, pp.117-138
Petrogenetic Aspects of Some Alkali Volcanic Rocks
J.F.G. Wilkinson
(Clarke Memorial Lecture, 14 July, 1977)
Abstract. The roles of low- and high-pressure fractional crystallization are examined and reservations expressed concerning their validity as controls in the genesis of certain alkaline volcanics. These reservations arise largely because of very limited data documenting the existence of the appropriate complementary crystal extracts required by fractional crystallization models. Low-pressure fractionation trends in alkali feldspar-bearing olivine nephelinites from the Inverell area, New South Wales, are defined by the compositions of schlieren and leucocratic veinlets. These indicate the capacity of olivine nephelinites to ultimately yield phonolitic derivatives via transitional malignitic compositions. The vitric residuum in a highly undersaturated vitrophyric phonolite from the Dunedin Volcano, East Otago, is mildly peralkaline. However, peralkalinity in potential derivatives of such highly undersaturated ac-free salic parents, crystallizing nepheline before Ca-bearing alkali feldspars, is largely suppressed until the parent melts experience extensive crystallization on or close to the respective nepheline-alkali feldspar field boundaries.
The efficacy of high-pressure fractionation (P > 10 kb), largely controlled by kaersutitic amphibole and lesser olivine and clinopyroxene, in the genesis of certain 'evolved' (but nevertheless displaying relatively high 100 Mg/Mg+Fe ratios) alkaline volcanics (hawaiites, nepheline mugearites, nepheline benmoreites, etc.) containing Cr-diopside lherzolite xenoliths is examined with particular reference to specific eruptives from the Newer Volcanics of Victoria. This model finds little support in the (relative) abundances or frequencies of occurrence of the phases (megacrysts) comprising the alleged high-pressure crystal extracts. It is proposed that at least some 'evolved' high-pressure alkaline volcanics may be the products of direct partial melting of relatively iron-rich lherzolites (100 Mg/Mg+Fe ~ 80-86).
Vol 110 pts 3-4, pp.139-145
Fossil Marsupials from the Douglas Cave, Near Stuart Town, New South Wales
John D. Gorter
Abstract. Marsupial remains from the Douglas Cave include Thylacinus cynocephalus, Dasyurus viverrinus, Sminthopsis sp., Antechinus sp., Phascogale tapoatafa, Perameles nasuta, Isoodon obesulus, Cercartetus nanus, ?Acrobates sp., Lasiorhinus sp., Potorous tridactylus, Thylogale stigmatica, Wallabia bicolor, Macropus sp., M. agilla, M. giganteus, M. titan and M. altus. A radiocarbon date of 29,200 years was obtained from near the base (Frank, 1969) of the older cave earth unit.