Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/59

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GEOLOGY OF NORTH GIPPSLAND, VICTORIA.
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are found here, also other vegetable impressions not sufficiently distinct to be determined." He adds that these plant-beds are underlain by a great thickness of purple-red rubbly and nodular shales, interstratified with purple-red and claret-coloured sandstones.

Professor M'Coy, in his essay on the Palæontology of Victoria (Exhibition Essays, 1866), says that the sandstones of the Avon were the only trace of the Carboniferous formation which he could recognize in Victoria, and the only fossil from them, the Lepidodendron, identical with that recognized by him many years before from New South Wales and Queensland; and further, in the 'Prodromus of the Palæontology of Victoria,' Decade I., he figures and describes this among the Palæozoic coal-plants (Carboniferous series) as Lepidodendron australe, M'Coy.

Up to the present time opportunity has been wanting to enable me to visit the Avon country and make a personal examination. As I have already pointed out, the Avon Sandstones do not extend at any rate to the eastward of Maximilian Creek, and thus the bounds have been narrowed down within which the correlation of the Lepidodendron-beds, of the Avon with the Archæopteris-beds of Iguana Creek is to be sought. Present information leads me to suspect that the passage may be gradual and undefined.

III. Tertiary.

Passing upwards from the rocks of the last-described period, there is an immense break in the geological series; the missing part of the record seems so completely lost that there are no means, so far as my present knowledge goes, to enable us even to suspect where any portions of it ever existed in the district I describe.

In looking at the sketch section, fig. 1 (p. 6), it will be seen at once that the Palæozoic rocks form a great mass of mountainous country fringed on the north and south by Tertiary deposits; the former those of the "Murray basin," the latter marine. Whether the Mesozoic Coal-measures of South Gippsland extended over the northern part of the district, in the same way that we see the Upper Palæozoic groups did, is not known. There are at present no data; but, so far as I can judge, it seems to me very doubtful.

4. Miocene.

(h) Bairnsdale Limestone.—The oldest of the Tertiary formations in North Gippsland is the Bairnsdale Limestone, collections of fossils from which have been referred by Professor M'Coy to the Middle Miocene period[1]; it is of the age of similar marine limestones of Corio Pay and other localities in Victoria. It is a coarse shelly limestone, which varies locally in texture, being in some places without apparent stratification for considerable thicknesses. Numerous remains of species Cypræa, Ostrea, Pecten, and Brachiopoda are frequent, together with a large echinoid, probably a Clypeaster. It shows itself in the river-valleys of the Mitchell, the Nicholson, and the

  1. Geological Survey of Victoria, No. 2. p. 72.