Belemnites are strewn over the surface of the two ridges which front the Cattle-station huts, but they are rarely found in the soft shales which crop out from under an escarpment of "Desert Sandstone."
The lithological character of these Cretaceous strata is such that decomposition is rapid ; and cliff-sections are accordingly very rare, the resulting physical aspect being that of vast plains, which form the principal feature of Queensland scenery west of the main dividing range ; but that the " Desert Sandstone " has extended over all this country is evidenced by its existence either in the form of outliers, or as a marked feature in situ on all main watersheds, or by its pebbles of quartz and conglomerate, which are strewn everywhere over the surface of the plains. The appearance of these vast plains is shown in Fig. 8.
The height of the watershed between the Thompson and Flinders rivers is locally not more than 1400 feet above sea-level ; and as
Fig. 8. — Physical Character of Cretaceous Strata, Flinders River, Western Queensland.
the former river has to travel as many miles before reaching the sea, it is easy to understand why, in a country subject to heavy tropical rains at one period of the year followed by a long dry season, the river-channels are ill-defined, and vast tracts of country covered by alluvial deposits.
Down the Thompson and its tributaries these Mesozoic rocks are known to extend, though much obscured by flood-drifts. The first to draw attention to the fact was the Rev. W. B. Clarke, F.G.S., of Sydney, who in the year 1867 received a suite of fossils from "Wollumbilla Creek and the surrounding district, which he described in
VOL. XXVIII. PART I. X
