Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/60

34 Tambo rivers, and on the banks of the arms of Lake Tyers; but it does not seem anywhere to extend to the hills of older formation on the north or to the sea-coast on the south. Its surface has evidently been much affected by denudation and is irregular. The rivers have cut deeply into it, leaving high yellow cliffs, which are rugged or crumbling as the texture of the great limestone bed varies. It probably does not anywhere rise more than 250 to 300 feet above the sea-level.

(i) Moitun-Creek beds &c.—Overlying the Bairnsdale Limestone, filling in its hollows and extending from the hills to the sea-coast, are the Upper Tertiary or Pliocene beds. These are mainly sandy, clayey, or gravelly deposits, with sometimes, as at Sandy Creek, coarse sandy flags or ferruginous conglomerates, with occasional concretionary ferruginous bands containing casts of marine shells. Collections of these have been submitted to Professor M'Coy, who considers them to be Lower Pliocene and, in some cases, possibly Upper Miocene.

On the sea-coast at Jemmy's Point there are calcareous sandstones and marls with Upper Pliocene shells similar to those of Wanganui in New Zealand, and characterized among others by a new Trigonia (T. Howitti, M'Coy) and by a Struthiolaria.

These marine Tertiary formations, speaking of the whole, rise gently from the sea-coast, and thin out, as I have before indicated, in the hill-country at heights which vary somewhat in places, but which probably may be taken at an average of from 600 to 700 feet above sea-level; and I think that no traces of any marine formation of Tertiary age are to be found at more than 800 feet above the sea. At any rate, though well acquainted with the whole line of contact, I know of none.

The Upper Pliocene fossils of Jemmy's Point and Lake Tyers are the youngest yet found. Regarding these formations in their strati- graphical relations, there does not appear to be any well-marked break or unconformity to the present time. The indications of changing conditions are those seen in the slightly varying composition of the various beds and in the evidence of long-continued but intermitting elevation of the land, continuing probably to the present time.

We may assume that the upper margin of the sandy and clayey beds represents a period somewhat later than the Upper Pliocene sandstones of Jemmy's Point, on which similar sandy clays and ferruginous conglomerate beds rest in places. We see that subsequently the rivers have excavated wide valleys in the Tertiary fringe of the land. There are also to be seen a series of two or more ter- races, extending often from near the coast-line, almost invariably