Journal and Proceedings of
The Royal Society of New South Wales
Volume 110 Parts 1 and 2 [Issued 14 July 1977]
CONTENTS
| AUTHORS & TITLES | PAGES |
| Henry, H.M., Catastrophic Channel Changes in the Macdonald Valley, New South Wales,1919-1955 | 1-16 |
| Roy, P.S., Does the Hunter River Supply Sand to the New South Wales Coast Today? | 17-34 |
| Embleton, B.J.J., A Late Devonian Palaeomagnetic Pole for the Mulga Downs Group, Western New South Wales | 25-27 |
| Cerone, Pietro and Keane, Austin, Series of Roots of a Transcendental Equation | 29-31 |
| Bourke, D.J., Gould, R.E., Helby, R., Morgan R. and Retallack, G.J., Floral Evidence for a Middle Triassic Age of the Gunnee Beds and Gragin Conglomerate, near Delungra, New South Wales | 33-40 |
| Martin, Helene A., The Tertiary Stratigraphic Palynology of the Murray Basin in New South Wales. 1. The Hay-Balranald-Wakool Districts | 41-47 |
| Chaffer, Edric, Leather – Why is it so? [Presidential Address, April 7 1976] |
49-59 |
Vol 110 pts 1-2, pp.1-16
Catastrophic Channel Changes in the Macdonald Valley, New South Wales, 1949-1955
H. M. Henry
Abstract. Floods in the Macdonald valley, near Wiseman's Ferry, New South Wales between 1949–1955 transformed the initially narrow V-shaped channel into a very wide channel with oversteepened banks. The difficulty of quantifying as distinct from recognising change in a river channel more than twenty years after it occurred is greatly increased in the absence of largescale maps, aerial photography and streamflow records. Buried bridges, the downstream displacement of wharves, tidal changes, the ponding of tributary creeks, old photographs and survey plans, and information obtained from farmers have been used to reconstruct the character and extent of channel change. There are signs that since 1969 the river may have begun to resume its pre-1949 form by narrowing its channel and lowering its bed.
Vol 110 pts 1-2, pp.17-34
Does the Hunter River Supply Sand to the New South Wales Coast Today?
P. S. Roy
Abstract. The possibility that terrestrial sand is being added to the open coast by the Hunter River was investigated by sediment sampling. Medium-fine quartz sand infills the lower 9.5 km of the Hunter estuary. This deposit is the product of a now largely inactive, landward transport of marine sand from the open coast. Lithic river sand of terrestrial origin occurs upstream of the marine sand and becomes finer in a seaward direction. Minor amounts of very fine river sand are admixed with coarser marine sand in the lower estuary. Superficial deposits of terrestrial mud also occur in those parts of the lower estuary that have been dredged. Very fine river sediment is periodically flushed out to sea by floods. It does not accumulate in the high energy nearshore environment but settles in deeper water further offshore. Under present day conditions the Hunter River does not contribute significant amounts of sand to the adjacent beaches or nearshore zone.
Vol 110 pts 1-2, pp.25-27
A Late Devonian Palaeomagnetic Pole for the Mulga Downs Group, Western New South Wales
B. J. J. Embleton
Abstract. The thermal stability of the magnetism in specimens from fourteen oriented core samples of red-beds belonging to the Mulga Downs Group was satisfactorily tested using the progressive partial thermal demagnetization technique up to 620°C. Magnetic remanence considered primary and acquired at the time of rock formation was isolated in twenty-one specimens from twelve samples: they yield a palaeomagnetic pole situated at 54°S, 96°E (A95 = 11°). This supports an earlier result obtained from the Middle Devonian Housetop Granite of Tasmania but differs substantially from results obtained from the Lochiel Formation of southeastern New South Wales. The result from the Mulga Downs Group is interpreted as emphasizing the discrepancy between the Palaeozoic palaeomagnetic results from the main Australian platform, and those from the Lachlan Fold Belt.
Vol 110 pts 1-2, pp.29-31
Series of Roots of a Transcendental Equation
Petro Cerone and Austin Keane
Vol 110 pts 1-2, pp.33-40
Floral Evidence for a Middle Triassic Age of the Gunnee Beds and Gragin Conglomerate, near Delungra, New South Wales
D. J. Bourke, R. E. Gould, R. Helby, R. Morgan AND G. J. Retallack
Abstract. The Gunnee Beds, near Delungra, northern New South Wales, are a sequence of arkose, conglomerate, prominent sublabile sandstones, carbonaceous shale, and coal, unconformably overlying Late Palaeozoic rocks of the New England Fold Belt, and overlain by the Gragin Conglomerate with cobbles of quartzfeldspar porphyry and acid volcanics. Megafossil and microfossil floras obtained from the Gunnee Beds and Gragin Conglomerate indicate a Middle Triassic age. These are the only Triassic strata which crop out in the Warialda Trough on the west of the Woolomin-Texas Block of the New England Fold Belt. Deposition and preservation of Middle Triassic terrestrial sediments both east and west of the New England region, indicate that the major unroofing of the New England Batholith had probably been completed by this time.
Vol 110 pts 1-2, pp.41-47
The Tertiary Stratigraphic Palynology of the Murray Basin in New South Wales. 1. The Hay-Balranald-Wakool Districts
Helene A. Martin
Abstract. The Hay, Balranald and Wakool districts are situated on entirely non-marine sediments, to the east of the limit of marine transgression of the Murray Basin. This palynological study of ten selected bores relates the sediments to the geological time scale by correlating the assembIages with the spore-pollen zones described for the Gippsland Basin. In this part of New South Wales, the deepest and oldest sediments, below 305m, are middle Eocene in age. Late Eocene assemblages are found below about 274m. Oligocene - early Miocene sediments form thick sections between approximate levels of 120m and 270m, and are encountered in every bore. Carbonaceous clays and lignites are common and the climate during deposition of these sediments must have been very humid, with lakes and swamps a feature of the landscape. Middle Miocene and younger assemblages have been recovered from only four of the bores examined. During deposition of the upper 100m, it appears that conditions were not favourable for pollen preservation. About the middle Miocene, the deposition of carbonaceous clays and lignites ceased and the rainfall must have decreased, although the continuance of the grey colour of the clays indicates that it was uniformly distributed through the year, with no marked dry season.
Vol 110 pts 1-2, pp.49-59
Leather – Why Is It So?
Edric Chaffer
[Presidential Address, April 7 1976]
Abstract. The fibre structure of hide, skin and leather is developed as one of the earliest fibre sciences, the fundamentals involved in its modification, and also that of its major protein constituent – Collagen – are highlighted, together with a brief outline of some processing involved in leather manufacture. Some of the important properties of leather affecting its everyday application and comfort are also elucidated.