Page:A sketch of the physical structure of Australia.djvu/32

20 definite account of this district of New South Wales than of any of the others. Immediately north of Illawarra, and on a line running thence nearly due north, about forty miles, to Campbeltown, we get the following section.

In the descending order.

1. Black and brown shales (named, I think, by Mr. Clarke, Wyanamatta shales,) 300 ft. and upwards.

2. The Sydney sandstone (or Hawksbury sandstone), thick sandstones, with a few thin beds of shale in its upper and lower parts; about 700 or 800 ft.

3. Alternations of sandstone and shale; about 400 ft.

4. Alternations of sandstone and shale, with much fossil wood (often drifted) and some beds of coal; 200 or 300 feet.

5. Wollongong sandstones, with calcareous concretions, containing many fossil shells and corals, and some fossil wood; 300 or 400 feet.

Total, 1,900 to 2,200 ft.

The beds here enumerated are probably but a portion of the palæozoic formation of Australia, as there may be found in other places beds much above No. 1, and there are almost certainly beds lower than No. 5.

In these four upper divisions, No. 1 to 4, the fossils are chiefly vegetable, containing among others:

There are also, I believe, in No. 1, fossil fish to be found, which have not yet been examined so as to determine their genus and species.

In No. 5, the Wollongong sandstone, which is frequently calcareous, and has large and small calcareous nodular concretions, I collected the following fossils: