The following is the preliminary report of Mr. Hardman, the Government Geolo- gist, with respect to work accomplished by him during the Kimberley survey of
Survey Office, Perth, January 13th, 1885.
I have the honor to submit, for the infor- mation of His Excellency the Governor, the following preliminary report on the geologic- al work done by me while accompanying the Kimberley Survey party in 1884,
Soon after landing in April, I accompanied Mr. Johnston to Point Torment, and exam- ined several wells, then in progress of being sunk in search of water, giving Mr. Fair- bairn my opinion as to the possibilities of ob- taining fresh water. The search, however, proved abortive, yet I consider that fresh water may be found at some further distance from the coast. On returning to Derby pre- parations were made for our expedition to the upper reaches of the River Margaret, and to the Ord River ; and these being finally completed at the Yeeda Station by the 21st April, we on that day started up the Fitzroy. As it was apparent that Mr. Johnston's duties would oblige him to visit a much greater extent of country than Mr. Turner, whose work would lie almost wholly along the rivers, I determined to attach myself to the party of the former officer, and I accom- panied him during the whole of his journey.
We travelled up the river to Mt. Camp- bell, and there commenced work, visiting many of the outlying hills and ranges, and obtaining several interesting cross-sections elucidating the geology of the country ; and, by the 21st May, we had reached the river Margaret, where it enters the Leopold Ranges, about 250 miles above the mouth of the Fitzroy. We now proceeded up the Margeret, following principally one of the minor branches--the May River-and visit- ing and examining many hills and ranges not hitherto mapped. On the 24th of June we crossed the watershed of the Margaret and Ord Rivers, at an estimated elevation (by barometer) of about 1,215 feet above the sea. Soon after this we came upon a small creek, which in a short distance widened out into a large and important river, flowing North- easterly. There can be little hesitation in regarding this river, which we named the Elvira, as the head-waters of the river Ord. Following this branch down, we after- some weeks reached the Panton River, and Mr. Johnston having selected a suitable site for a base line some 10 miles below the junction, we remained there for 10 days, while the necessary clearings and measurements were being proceeded with. On the 21st July we left for the Ord, and proceeded along it until the 1st August, when we camped a few miles below the junction of the Ord and Negri Rivers, where we remained for some days in order to visit and examine various localities in the neighbourhood. On the 6th August we left for the Negri, up which we passed for some 35 miles, finally camping near Mt. Panton, and remaining their until the 11th, having visited and examined Mt. Napier, a part of a basaltic range south of the Negri. We then commenced our return journey, which we had traversed on our course up, and we necassarily lay chiefly over the same ground arrived at Derby on the 17th Novem- ber ; leaving for Fremantle by steamer of 5th December. During this journey I travelled about 1,900 miles on horseback, and the ob- servations I made will enable me to furnish a sketch map showing the "geology of about 10,000 square miles of country.
The wide-spread area occupied by the car- boniferous rocks in Kimberley cannot but be of the highest interest to geologists; These I last year traced out over a considerable tract of country, and have now been enabled to follow them out for a still greater extent. Besides this, I have been fortunate enough to discover a formation hitherto unknown in Western Australia-namely, the Devonian. These rocks, resting on the metamorphic beds of the silurian, cover a very large space in the district. One of the most interesting discoveries made during the trip, however, is that of a great mass of basaltic rock which was traced for more than 100 miles. It forms a very extensive plateau, rising in places more than 1000 feet above the river plains, and is probably at least 2000 feet above sea level ; its area, so far as observed, is at least 3000 square miles. Its age is Devonian. Apart from the scientific interest attaching to the discovery of such an extensive flow of vol- canic rock of that period, there is the practi- cal importance due to the fact that although this great plateau is for the most part com- posed of almost bare rock, it is well covered with several varieties of soft grasses, and edible shrubs, even to the summits of the hills ; and will afford excellent pasturage. This is due to the fertile nature of the soils produced through the decomposition of basal- tic rocks, a fact which is well exemplified,in, other parts of this colony, and is so well known that it need not here be enlarged on.
Minerals, &c. (Gold).-I am glad to be able to report that I have discovered a large area of country which I believe will prove to be auriferous to a payable degree. This country is traversed by the Margaret, Mary, Elvira, Panton, and Ord Rivers, and comprises an area of at least 2000 square miles, so far as observed ; but it doubtless continues over a much greater extent of country. The for- mation is principally lower Silurian slate and schist of various kinds, traversed by on enormous number of quartz reefs. In some localities many of these occur in the space of a few hundred yards, and it was quite usual to notice 25 or 30 large reefs while riding over a mile of ground, without taking into account the smaller reefs or veins. The quartz constituting these reefs is of a very promising character. It is a dull yellowish and grey quartz, very cellular and vuggy, containing quantities of black and other ox- ides of iron, together with casts of, and often crystals of, iron pyrites. From most of the surface quartz the enclosed minerals have been washed away however, although their traces are still apparent. Minute specks of gold have been noticed in a few cases, and I have very little doubt that many of these reefs, when properly examined and tested, will prove to be auriferous. These quartz reefs have a general bearing of N. 10 E. to N.E. Many run due N. & S. Some of them can be traced for several miles. It is most probable that these quartziferous rocks are a spur or continuation of the gold-bearing metamorphic rocks of the Northern Terri- tory, now being worked with some success.
Alluvial Gold.-The river valleys and flats are in many places covered with deposits, sometimes very extensive, of quartz-gravel, and drift ; the quartz being derived from de- nudation of the reefs referred to above. I have prospected these gravels over many miles of country, and I have rarely failed to obtain good colors of gold ; in many locali- ties of a very encouraging character. Very often good colors were obtained in every pan washed, in different trials in the same local- ity. I have thus found gold to be distributed over about 140 miles along the Elvira, Pan- ton, and Ord Eivers, &c. ; as well as on the Mary and Margaret Eivers, where the indic- ations were very good, and the appearance of the country most favorable. In several, instances I obtained good colors of gold at considerable distances from the quartz-bear- ing rocks from which the gold could only have been derived. This to my mind seems to indicate that there must be large quanti- ties of gold in these quartz-bearing rocks, and in the drifts immediately under-lying them. The gold yielding country is well watered by numerous rivers, creeks, and gullies, which even in the driest part of the year are never wholly without water. And although during the dry season water is scarce, there would be no difficulty in con- serving water anywhere in sufficient quan- tity for all mining purposes. On the whole, the indications I have met with point, as I believe, to the great probability of payable gold being obtained in this part of the Kim- berley, and are I consider sufficient to justify the expenditure, either by the Government or private individuals, of a reasonable sum of money in fitting out a party to thorough-
ly test the country, and I should strongly recommend such an undertaking. I would also suggest the advisability of parties going up for this purpose providing themselves with some simple apparatus for crushing and washing some of the reef quartz, as in one very rudely conducted experiment of this kind I obtained a small quantity of gold.
Other minerals obtained are-Lead Ores ; galena and carbonate of lead. Zinc : blonde Copper : native copper, green carbonate, and grey copper. Iron : brown hematite, magne- tic iron ore, titaniferous iron sand. Asbestos. From the general character of the rocks, I have no doubt that good veins of metallifer- ous mineral will be discovered. Amongst gems and precious stones are opal, cats-eye, chalcedony, moss agates, cornelian, onyx, &c, and yellow and pink topaz, ruby and garnet in small grains in the river sands. Agates and jaspers of various kinds sometimes form whole hill ranges and may hereafter prove valuable. Building stones of all varieties abound, and many of the igneous and meta- morphic rocks are highly ornamental. I have collected a large number of rock and fossil specimens, which are now in the Museum at Fremantle for arrangement. I have also ob- tained many photographs, sketches, and sec- tions for the illustration of my detailed re- port.
This, together with a geological map, I hope to be able to submit to you shortly-that is,
so soon as I shall have obtained the neces-
sary topographical data and map from the
I have, &c,
EDWARD T. HARDMAN,
To J. S. Brooking, Esq.,
Acting for Surveyor General
and Commissioner of Crown Lands.