149 
tad massive fine-grained sandstone sliglitly indurated. A sheet of intrusive felsite 
occurs in the black shales and semi-vitreoris sandstones. The whole series rests on 
<3iorite. In the bed of the creek, below the store, a sheet of diorite is seen overlying 
f>ed of argillaceous shale. 
It the foot of Mount Roy, on the western bank of Jolimont Creek, a white 
Semi-vitreous grit rests on decomposed diorite, and is succeeded by a contemporaneous 
sheet of dolerite, ten feet in thickness. The dolcritc is overlaid by a thick mass of 
^hite semi-vitreous sandstone, quartiioso, conglomerate, and yellowish grit, the whole 
hipping at 5° to 8° N.W. 
An outcrop of semi- vitreous sandstone is seen near Palm-tree Creek, on the 
®owen Road. Some portions of this rock appear as if a second deposition of quartz had 
^taen place subsequent to its formation. The sandstone rests on a volcanic ash or fine 
Agglomerate. 
In a quarry further north along the Bowen Road a contemporaneous sheet of 
hiorite, two foot thick, weathering into spheroidal masses, is overlaid by beds of argil- 
Aceous shale which dip to S.E. at 40° beneath dioritio lava. 
On the south bank of St. Helen’s Creek, and about two miles from the road, the 
Sedimentary rocks lie directly on an uneven surface of felspar porphyry. The escarp- 
®ient of the stratiform rocks can be traced for a considerable distance, and is well seen 
^^ere the creek cuts its way through a narrow gorge, whose flanks are made up of beds 
semi-vitreous sandstone and coarse conglomerate dipping at 5° to W. 
A low gap in a range between 8t. Helen’s Head Station and Mount Bairen is 
*'^ade Up of grits and fine conglomerates dipping at 55° to N. 50° E. 
„ In Black Rock Creek, near Selection 1450, a vertical seam of inferior coal, two 
. three inches in thickness, is intruded into by a sheet of greyish diorite. The coal 
Overlaid by buff-coloured shales. 
Sandstones, grits, and shales, with sheets of diorite and dolerite, are seen at 
^'^torvals in the low hills between Black Rock and Alligator Creeks. 
“ The stratiform series of volcanic rocks upon the uneven surface of which some 
th sedimentary series were laid down,” says Mr. Maitland, “are best developed on 
j ® tarthem side of the Pioneer River, where they cover a considerable tract of country, 
be P^Aco was their base seen, and consequently no estimate of their thickness could 
^ade. The rocks forming the series are diorites and basalts, with breccias and 
^sg omerates. Nowhere do these rocks form any conspicuous feature, occupying, as 
do, the rounded knobs on the lower ground.”* 
J. 
the greater part o£ the details given in this chapter are taken from Mr. A. Gibb Maitland s Report 
^'^kay District. Brisbane : by Authority ; 18S9. 
inh** Page 21. — Since this page vv.as in print, the Warden has reported (31st December, 1891) 
opinion, the Last Call Mine, Cloncurry, must have been “ salted.” 
