10 
blow comes from an erroneous idea that the ferruginous character is due to the action of fire; it is due 
however, to the action of water. The prominent character is owing to the hardness of the silicates of iron 
which resist the action of weathering. Miners as a rule thought them unworthy of notice, possibly from 
inability to explore them; they will, however, form a source of permanent mineral riches in the Northern 
Territory. With no other means of assay than a smith’s forge small samples of silver were obtained from 
another “ blow.” 
Cement Gully. —This is a shallow flat close to Grove Hill. It has low gently sloping ridges at each 
side, which are covered with broken stone—a quartzite in rather large angular fragments. The sinking was 
shallow, 10ft. to 12ft. There was much gold taken from this gully, which no doubt was derived from the 
ranges at each side ; yet in these there were no quartz lodes, but only a few unproductive leaders. In such 
cases the vein from which the gold was derived has been denuded down to where it cut out, and these 
leaders might indicate where it makes again. 
Neates ’ Gully .—A short marshy flat receiving the drainage of a narrow stony creek. Much alluvial 
gold was got from this valley. At the top of the ridges at each side there are quarz reefs, and at the head 
of the valley there is a mine now being worked on tribute by Chinamen. It seems a very good shoot of gold. 
Though irregular the lode looks excellent with a good show of gold ; there are a few scattered crystals of zinc 
blende, but much well developed crystals of iron sulphide. 
Margaret Creek. —The road to these mines leads along the side of the River Margaret, where the land is 
of excellent quality, chocolate brown and black, derived from the decomposition of diorites and the black 
carbonaceous alluvial of the creeks. Nearly all of this is under cultivation by the Chinese. Fine crops of 
maize, sugarcane, sweet potatoes, and culinary vegetables are visible all along the creek, fringed 
as usual by rugged green lines of bamboo. The diorite from which the soil is derived is an 
outcrop everywhere. It forms a broad range some 200ft. or so in height, often abutting on out¬ 
crop of slate at the bottom of the valley, or even surrounding such outcrops as if it had flowed 
around it. Its color varies between dark-green, gray, and black. The stone is in no case vesicular; it is 
entirely crystalline, showing a rock almost entirely composed of hornblende. At the head of the creek, 
about five miles from Port Darwin camp, there is a network of low quartz ridges, giving rise to many shallow 
short gullies, where the alluvial has been worked; the sinking was shallow in red earth ; about 20ft. or less to 
the bed rock the soil contained a few angular fragments of rock stratified horizontally. The bedrock was 
quartzite or felsite of various shades of yellow, red, and brown, with innumerable joints, in which the stratifi¬ 
cation was^ not very clear. There were many quartz veins from these leaders to lodes several feet thick. It 
may be inferred that these are intersected by dykes of diorite, for there were many fragments of this rock on 
the edges of the claims, but it was impossible to obtain any information on this subject from the Chinese. 
I here were two claims working on a quartz lode, but no crushing mill. It was stated that all the gold 
obtained was broken out of mullock by hand. Judging by the surface indications there appeared to be a 
dyke of diorite to the eastward, and then a thick quartz lode. This was said to be poor, presumably because 
no gold was found when a few stones were cracked on the surface. To the westward was another dioritic 
dyke at the base of what was called the tableland. Though somewhat resembling the appearance of the 
desert sandstone, this is probably a highly inclined outcrop of fluviatile sandstones, giving rise to precipitous 
escarpments dipping away from the stream. This goldfield has been entirely mined by Chinese, and most 
wretchedly mined. It has all the indications of a rich gold country; great quantities of gold have been 
got out of it, but no one can tell how much, and probably it has nearly all left the country. The district may 
employ prospectors for a long time to come, and probably has yet to reveal much important mineral wealth 
to the country. The fact of so many dioritic dykes forming a network as it were with quartz lodes indicate 
with certainty important mineral deposits. 
Grierson's Gully.—X broad flat, with low mammillated hills all round, very stony. It has been 
worked in shallow sinkings for alluvial gold. The gravel is small, in angular fragments of an inch or less, of 
blackish quartz rock and schist. Here and there a softer fragment is rounded as if by water, so that the 
alluvial is probably derived from weak currents. The Chinese work at the heads of the claims, and go 
cradling them over and over again. 
Sajidy Creek. Iliis valley is wide and open, with high, barren, stony ridges on each side, almost des¬ 
titute of timber. ^ The spurs from the ranges are almost regularly alternate from each side, and these give 
rise to a series of small gullies, which have all been more or less auriferous. Some of them have proved 
extremely rich. The ridges from which these gullies descend show quartz lodes, with an occasional con¬ 
spicuous outcrop of ironstone. It is said that the reefs have been prospected; but this can only have been 
done in a most superficial and imperfect manner. The whole of the ridges near Sandy creek have a most 
promising appearance. Diorite dykes are found at the foot of the ridges, and, like them, preserving more or 
less of meridional direction. It may be some time before capital and enterprise will be brought to bear on 
these ridges, but most certainly much mineral riches will be found to be contained amongst them. The road 
along Sandy creek leads to the Yam creek telegraph station, or the Shackle, as it is called. Alluvial sinking 
has been earned on almost to the doors of the telegraph office. Amid the wash gravel at the heads of the old 
there are a good many rounded lumps of magnesite (magnesian carbonate), which look like lumps 
of limestone in the gravel. There is no limestone anywhere near this locality. About two miles south of 
the 1 am creek telegraph-station the overland line passes through what is here termed a gorge, or open 
valley, bordered on each side by low outliers of tableland. In the bottom of the valley there are outcrops 
oi granite in the form of boulders in many places, and the same rock forms the sloping sides of the 
valley for 100ft. to 150ft. It is a pink granite with a black mica, and very large crystals of pink and 
yellowish orthoclase felspar. This formation is capped by red or purple horizontal strata some 50ft. in 
thickness. The rock is always much weathered and broken into irregular squares, and at a short distance 
the appearance is that of a ruined Avail. In some places the piles of weathered and highly colored stone assume 
ig most fantastic and artificial appearances. This is the so-called desert sandstone, which is supposed to form 
a continuous plateau over a considerable portion of Australia. 
At the place now referred to, the lower stratum lying immediately on the granite is a waterwom con- 
g omerate about 10ft. thick. It is of extraordinary hardness; the stones composing it arc completely water 
worn, and evenly, smoothly rounded. They consist for the most part of red quartz, but there are pebbles of 
c site and eurite. I here was no good opportunity for seeing the connection of the granite with this con- 
g omerate, but evidently it did not furnish the materials. Above this is about 35ft. of magnesian rock ; it 
is a compact soft yellowish white rock, with red stains. It consists of silicate of magnesia and carbonate 
o magnesia, with scarcely a trace of lime, but much iron oxide. On the lower slope there is a little rough 
carbonate of magnesia lying on the surface, derived from the weathering of the rock above. It is a globular 
compact 
