Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/342

 and sandstones, mostly red, and evidently partly fused by igneous action. The calcareous sandstone occurs along the creeks and downs where water has denuded it ; and above all is a coarse grit. The descending section in the creek-hank, where the fossiliferous nodules occur, at Wollumbilla is as follows : —

1. Brown stiff soil, full of pebbles of quartz much water-worn.

2. Clay.

3. Slate-coloured marl, very friable above, but hard below, charged with strings of crystalline carbonate of lime, and breaking into rectangular fragments. In this occur the calcareous masses. On the east, at about three miles distance, coarse conglomerates rise above these beds ; and to the west, coarse alluvial sand occurs. The height of the section is about 15 feet ; the bluff end of the conglomerate rises to about 20 feet, and from it to the surface slopes away to the eastward, the stratification being apparently horizontal.

It is not improbable, I think, that the metamorphosed condition of the sands and grits referred to above may be due to mineralogical rather than to igneous action.

The calcareous boulders from the Wollumbilla Creek, when broken, are found to be of a deep olive colour internally, a few presenting a dull brown or bluish hue. They are very compact. In all of them organic remains are very abundant. The exteriors of many of the boulders are very much water-worn, and exhibit only sections of the organic remains they contain ; whilst in others a certain amount of decomposition or oxidation of the surface has taken place, which has produced a rotten exterior, looking like an impure chalk, of a yellow or buff colour. When this is the case, the fossils stand out sharply from the matrix. An examination of the softer portions thus produced, has enabled me to detect the presence of Foraminifera (of nine European species) and Entomostraca, and many other remains which had not previously been recognized. One block of stone may be seen to be perforated in every direction by Serpuloe ; and there are to be recognized over its surface small teeth of fishes, Rhynchonelloe of several species, Argyope, Nucula, arms and scattered plates of Pentacrinites, Natica, Pecten, Avicula, &c. ; whilst masses of Purisiphonia, a new genus of : fibro-siliceous Sponges, which have resisted the decomposing action to which the blocks have been subjected, appear to be abundant. Other blocks seem to be almost composed of the detached valves of Conchifera, with an occasional Belemnite. From Maranoa there are examples in which the bed is seen to be almost made up of rolled and broken Belemnites, intermixed with small pebbles ; whilst another from the Downs on the Nive river contains nothing but a mass of Mactra.

As in Western Australia, a quantity of drift wood and vegetable matter is mixed up with the Queensland fossils ; and it appears evident, from the broken and abraded Belemnites and the condition of some of the shells, that they could not have been directly covered up, or that the parent beds were not deposited in a very tranquil ocean. One exception, however, to this is presented by blocks containing Pentacrinites from Mitchell Downs, which, though subse-