51 ? 
e.g., in the foundation course of tlie Cathedral at Townsville. The level of the 
surface of the Desert Sandstone at Burra (one hundred and sixty-nine miles) is 
1,817 feet. Prom Coalbrook Eaihvay Station (one hundred and ninety-five miles 
from Townsville — say 1,423 feet) T crossed the Desert Sandstone in January, 
1888,* on a course of N. 29° W. for a distance of eighteen miles to the Plinders. 
The country was flat and tame. A lmost from the loft bank of the Plinders the waters 
drain through open marshy plains and lightly timbered forest country southward into 
Bullock Creek, one of the feeders of Cooper’s Creek. The divide between the Gulf 
waters and those of the Great Australian Bight is thus crossed imperceptibly, although 
on the Colony Map it is denoted by shading indie.itive of a chain of mountains. The 
Desert Sandstone is covered by a more recent deposit of weathered, and in pai’t water - 
arranged material derived from its waste, and cemauted together with peroxide of iron 
and carbonate of lime. The soil derived from the latter deposit, it may be noticed, 
bears better grass than is usual in Desert Sandstone country. A good part of the 
district is fair pastoral land, with frequent parches of blue grass and only rare clumps 
of Triodia. On the left bank of the Plinders the Desert Sandstone, with a total 
thickness of about twenty feet, rests unconformably on Rolling Downs strata, including 
some coal-seams. The Desert Sandstone here consists of thin, almost flaggy, beds of 
yellow and white siliceous material, sometimes gritty and occasionally pebbly, the 
pebbles being invariably of white quartz. The bedding-planes and joints of the sand- 
stone are frequently coated with films or layers, up to oue-eighth of an inch in thickness, 
of binoxide of manganese. 
The thinning out of the sandstones of the great tableland is again well exemplified 
on the head of the Plinders River, f where I saw it in September, 1881. I may observe 
that I started on this journey with a broken collar-bone, and was consequently unable 
to do much climbing. The granite range dividing the Burdekiu from the Plinders is 
crossed by the Dalrymple and ITughenden Road, at an elevation of 3,040 feet (by 
Aneroid), and is flanked by a deposit of basaltic lava, disposed in nearly horizontal beds 
and extending to Dalrymple on the east, and to Tatoo Camp, seven miles above Wongalee 
Station, on the west. At Tatoo Camp a gully cuts through the lowest bed of basalt and 
exposes about fifty feet of the underlying Desert Sandstone. The sandstone is white 
or yellowish, with false-bedding, and with soft ferruginous portions, apt to weather 
into caverns. The only fossils observed were some twig-impressions. Triodia at once 
takes possession of the soil where the Desert Sandstone comes to the surface. It 
occupies, however, at this place, only a narrow bolt of country. The basalt occurs in 
outlying table-mountains between Porcupine Creek and the Plinders, as far as Mount 
Beckford, where it rests on the Desert Sandstone at an elevation (by Aneroid) of 
1,800 feet. 
The Section (Plate 45, tig. 1) shows the relation of the Desert Sandstone and 
basalt between the Burdekin and the Plinders. 
The Runs Map of Mitchell District shows about a score of little isolated table- 
lands, which are outliers from the large tableland above described, and attest the former 
extension of the Desert Saud.stone to the west, although at slightly lower levels than 
that of the base of the main tableland. The Desert Sandstone undoubtedly covered 
the whole Mitchell District, and the present surface of the Rolling Downs over the 
whole district is only a little lower than that on which the Desert Sandstone was 
deposited. 
* Report by R. L. Jack., On Goal Discoveries on the Flinders. Brisbane ; by Authority : 18S8. 
t See Transcontinental Railway Report. By R. L. Jack. 1885. 
