582 
DaJrymple, on the Burdekin (see Diagram-Section PI. 45, fig. 1). On the western 
side similar basaltic lavas extend to Tatoo Camp, seven miles above Wongaleo Station. 
Hero, at an elevation of 1,840 feet, the lowest bed of the basalt is seen resting on the 
Desert Sandstone. Outliers of the basalt occur between Porcupine Creek and the 
Flinders as far as Mount Beckford. In all probability it extended over a considerable 
portion of the Western interior, from which both it and the Desert Sandstone have now 
been denuded. 
Horth of Coal brook Station, on the Northern Bail way, fragments of basaltic 
lava-flows are seen resting on the Desert Sandstone, on the divide between the heads of 
the Thomson and Flinders Eivers. 
Mr. Bands describes * a basalt about fifty feet in thickness overlying Desert 
>3and8toni3 in a canon of the Walker Eiver (Head of the Flinders), which has been cut 
through both rocks to the depth of two hundred feet. And in the same river, two and 
a-half or three miles above the junction of the White Mountain Creek, he says,t 
“ The Desert Sandstone is seen faultedagainst the schists by afault running east south-east 
and dipping south-south-west. I’he schists and Desert Sandstone are both covered with 
basalt. The Desert Sandstone is bent up near the faidt, and is dipping south-south- 
west.” Here we have an instance showing that a suflicient period elapsed after the 
deposition of the Desert Sandstone to permit of its upheaval, probably accompanied 
by faulting and p)artial deirudation, before the basalt was poured over it. 
In the same Eeport, Mr. Bands describes “ a vast table-laud of basalt extending 
for many miles” to the west of the Walker Biver. “Eemnants of this basaltic table- 
land occur on the east side of the river, between it and Oxley Creek, forming ‘ outliers ’ 
which have been separated by watercourses. The remainder of this ba.salt has been 
entirely removed by denudation. The cavities in the basalt are full of zeolites. Thin 
sections of the basalt under the microscope show it to be made up of a ground mass of 
small interlaced crystals of felspar, with crystals of olivine throughout it. The olivine 
crystals are much decomposed, especially around the margins of and along the cracks 
in the crystals. It contains very little magnetite. The basalt is clearly of Tertiary 
age, overlying, as it does, the Desert Sandstone.” 
Mr. Bands, speaking of the Cape Gold Field, says : — “ The only instance of basalt 
on the Cape side of the I’ange is that of Mount Black, situated about nine miles west 
of the Upper Cape. Mount Black is a hill of schist, capped with basalt about two 
hundred feet in thickness. The latter is a dense olivine-basalt, and has in places 
assumed a columnar structure. It possesses magnetic polarity.”J 
An immense area of horizontal basalt occupies the whole district extending from 
Lake Cargoon and Wandovale on the west to the Burdekin on the east, and from 
Lolworth Creek on the south to the heads of Emu and Maryvale Creeks on the north. 
Beds of w'hite pipe-clay are occasionally met with between the beds of basalt. This 
area is ivatered by Lolworth, Fletcher’s, Allingham’s, Emu, and Maryvale Creeks, and 
the Basalt Eiver. In Maryvale Creek the “ Diprotodon-breccia” described by Daintree 
occurs, so that we here have the age of the basalts defined so far as that they lie 
between the Upper Cretaceous and the Post-Tertiary. The basalts of this area are 
known to overlie, at least in their northern portion, gold-bearing drifts, which, however, 
have never been prospected to any extent. 
Further north, between the heads of the Broken Biver (a tributary of the 
Clarke) and those of the Einasleigh, horizontal beds of basalt cover a wide stretch of 
* Iteporb on the Cape Gold Field. Brisbane : by Authority : 1891, p. 11. 
t Loc. cit. 
J Ann. Progress Report Geol. Survey of Queensland for 1890. Brisbane : by Authority : 1891. 
