68 
The loam forms patches of rich red soil (generally thickly timbered with 
gimlet wood). 
There is very little to be seen of the Plutonic rocks at the surface; a few 
small diorite dykes occur in the range, and probably some of the granites at tlie 
base of the hills are intrusive. 
Quartz reefs in this district are quite a rarity. They are small, of a yellow 
glassy appearance, containing either pyrites or brown hematite and a little gold. 
They are well-defined walls, dipping at an angle of about 65° in a North-West, 
direction, following the strike of the rocks North-East and South-West. When 
opened, some very good specimens and prospects, both from the reefs and the 
casing, were obtained. 
The size of the reef is unknown, as, owing to the hard nature of the ground, 
and to the discovery of many richer reefs at Yilgarn, it has been abandoned. 
PILBARRA GOLDFIELD. 
(Proclaimed July 1889). 
Proclaimed Area , 32,000 Square Miles. 
The Pilbarra goldfield is situated in that portion of the Colony known as “The 
North-West,” that is, the district lying between the coast on the North, the 
Fortescue River on the South, and the De Grey River and War burton's Great 
Sandy Table-land on the East. It is a most promising mineral area. The 
general features are a large low alluvial plain which follows the coast, broken 
here and there by rocky hills, whilst to the South and East rises a high table¬ 
land. 
Several large rivers have their sources on the Northern edge of this plateau, 
and cutting deep gorges through the upper horizontally bedded rocks expose the 
underlying crystalline rocks across the strike of which they have cut their channels. 
These water- courses trend towards the North and North-West in deep gorges cut 
through the limestone and quartzite rocks, then through flats bounded by rough 
sandstone ranges, and on by deep ravines through rough broken hills of schists, 
slates, sandstones, quartzites, conglomerates, and amygdaloids, containing trap 
dykes, into large alluvial plains, with here and there bold massive hills of amyg¬ 
daloid and small peaks of quartz, granite, and ironstone, around which soft calca¬ 
reous slates often rise to the surface but never form hills much above the level of 
the plain. These plains extend to the sea coast, where they are fringed by man¬ 
grove swamps, except where trap rocks extrude and form a bold rocky coast. The 
amygdaloids in many places are split up into rough blocks, which become red or 
black on the surface, and then present the appearance of a huge heap of stones, 
without a trace of soil or vegetation. They contain vast numbers of agates, ealcite 
crystals, and other enclosures, so that it would be well worth prospecting the 
streams running through them for precious stones. 
Mallina. 
Mallina is between 65 and 70 miles to the Eastward of Roebourne, and about 
16 miles South from the coast. It was here that the first discovery of gold in the 
North-West was made, in the year 1888, when a boy named Withnell picked up a 
piece of stone to throw at a crow and noticed the gold in it. 
Here the gold is associated with sulphide of antimony, and in parts it is very 
rich, but the portion of the reef which carries much gold is small, although the 
reef itself is of great size. 
