6 
INAUGURAL ADDRESS, 
Charters lowers Gold Field exhibits a good illustration of this class 
of auriferous intrusive granite. Here the intrusive granite appears 
as a dyke of great thickness, exceeding a mile, with a length of twenty 
miles ; the rock is well-crystallised quartz and felspar, with very little 
mica or hornblende. One shaft has been sunk 2,000 feet to a floor 
showing gold, and similar to the floors that outcrop on the surface. 
Ihe dip ot these floors is north, about 30 degrees from the horizontal, 
and the strike across the direction of the dyke. There are, however, 
no good natural cross sections, as the watercourses are small, so that 
the length and breadth have to be estimated to some extent bv the 
character of the soil derived from the decomposed rock, it being more 
fertile than that of the other rocks in the locality. The exploratory 
shafts which have been sunk are in positions selected for the purpose 
of reaching known sheets of ore at greater depth, or under the 
impression that the ore deposits were true fissure lodes, and would 
have extension in the direction of the discovered outcrops, are there- 
fore not calculated to extend our knowledge of the auriferous deposits. 
The most instructive instance of the occurrence of auriferous intrusive 
granite exists in the valley of the Brisbane River, near Eskdale, where 
a granitoid dyke 50 yards wide, cuts through a slate hill for a distance 
of three miles, and in places shows thin sheets of quartz containing 
gold ; the strike is at right angles to the length of the dyke, and 
the dip 30 degrees, ^ome of the quartz sheets have been traced 
across the dyke to within an inch of the slate which encloses it, but 
there is no trace of any variation in the sedimentary slate opposite the 
end of the quartz. A small watercourse cuts through the dyke and 
exposes arsenical pyrites and iron oxide, with small particles of gold. 
A more accessible instance of intrusive granite is exposed in the 
cutting for the bywash of the Brisbane Waterworks, at Enoggera, 
where the igneous rock has intruded between the strata of the slate. 
PERMO-CARBONIFEROUS ROCKS. 
Erom the middle to the close of the Permo-Carboniferous period 
the dry land teemed with vegetation, of which the Lepidodendron was 
a conspicuous type, along the eastern division, for though this plant 
was most abundant in Queensland it is also found in Victoria, and 
on the Philips River, in West Australia, where the later Permo- 
Carboniferous rocks are found on the south coast, extending from 
Albany eastward to Israelite Bay, forming the Stirling Range, with an 
elevation of 3,000 feet, the Mounts Barren, and the Russell Range. 
The age of these rocks is determined by the occurrence of large frag- 
ments of carbonised vegetation, the aspect of which closely resembles 
Lepidodendron stems. This formation is limited to the coast district, 
as, at a distance of fifty miles inland, the granitic plateau is reached 
with its partial covering of Devonian slates. On the northern coast 
