miles towards the Murray and the boundary of the province of Victoria. Probably they reach far into the interior ; and it is by no means improbable that the tertiary sea divided "Western Australia from the eastern provinces.
Selwyn's Survey-map of Victoria indicates the development of the Tertiaries of that province, of the basalts which frequently cover them, and of the upper tertiary beds of doubtful age, which here and there hide every thing, and reduce the luxuriant vegetation of the soils of the older rocks to scrub.
Strata of sedimentary or volcanic origin, referable to some section of tertiary or recent time, occupy probably fully one-half, or over 40,000 square miles, of the surface of Victoria. They are found resting unconformably on all the older formations, igneous and stratified, and range from the sea-level to elevations of over 4000 feet. They include groups of strata of earth, loam, sand, clay, gravel, conglomerate, ferruginous and calcareous sandstones and grits, hard, gritty rock, marble and other kinds of limestone, and various volcanic products.
The tertiary deposits, containing marine fossils, fringe the coast, and extend about sixteen miles inland on the eastern side of the province, between Wilson's Promontory and Cape Howe, resting probably upon Palaeozoic rocks. On the west they form a more important series, reaching from the mouth of the Glenelg to Cape Otway. In this part of the province they extend northwards under a vast development of basalt for more than forty miles, and are well seen at Hamilton. The supporting strata are Palaeozoic rocks and Tceniopteris-sandstones. Between Cape Otway and Wilson's Promontory, especially close to Port-Phillip Bay, these tertiary deposits are found on sandstones and on basalt. In this locality, some of the tertiaries have had an older geological age given to them than the prevailing type, and all are very fossiliferous. Par away to the north-west, the fossiliferous tertiaries have been found on the northern bank of the Glenelg ; and vast plains of sand, ferruginous gravel, and clays in that region overlie the equivalent deposits of the coast- line. To the north and north-east was the old coast-line, now occupied by the Palaeozoic rocks.
No tertiary deposits containing marine fossils have been found at a greater elevation than about 600 feet above the level of the sea, and no tertiary beds whatever, containing marine fossils, have been recognized east of Cape Howe, in any part of New South Wales.
The published sections of the tertiaries do not show any examples of great contortion of their strata, except near Cape Otway ; and there the beds were deposited in a trough of highly contorted sandstone, and probably were more displaced by the operations of denudation and re-deposition than by any other causes. The thickness of the fossiliferous tertiaries is very variable. It is unknown in many places, and reaches to about 300 feet in the best-exposed sections, whilst, where much denudation has taken place, not more than a few feet of the rock may exist. Pure limestone, except in
