4

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The reef in Sealers' Creek, which lies somewhat to the westward of the south extension of the Morning Star line, has not been prospected, except at the surface, at which patches of rich stone can be seen, or the stone may be proved to be rich by crushing and washing. On Steep-to Island and at Cuttle Cove prospecting for or upon reefs is at present at a standstill. On Steep-to Island no distinct line of reef has been found, while at Cuttle Cove the reefs reported as yielding payable gold are thin, and the samples brought to Wellington did not yield more than a trace of gold. All these reefs are contained within a development of Lower Silurian rocks that lie between the granite mountains and the coast-line, and which, from the shore of Foveaux Strait, extends northwest from the mouth of Kiwi Burn across Preservation and Chalky Inlets to the northern shore of the latter at North Port. In the northern part, the lower portion of the series has been altered to metamorphic rocks that contain much carbon, while towards the east, where the original rocks were of a more arenaceous type, the change is in the direction of micaceous quartzites, with lesser developments of mica-schist, into which numerous veins of granite have been intruded. The higher rocks of the series are less altered, and at places contain abundant fossil remains, indicating the age and period to which the rocks have been referred. Within the granite region, lodes carrying ores of the metals are rare. Bradshaw's reef, on the western shore of Isthmus Sound, occurs in granite, and appears as a well-defined and continuous lode, carrying gold, silver, copper, lead, zinc, and iron, and forming a mineral vein 2ft. to 3ft. wide. The ores of the various metals named are generally mixed throughout the lode, but usually the copper-ore replaces the galena. The galena of the lode is, next to the iron, the more abundant ore, and, when pure, contains 120oz. of silver to the ton. To the north-east and east of the north-west extension of the granite, there is a large area of country over which highly-metamorphic schists are present. These rocks begin near the head of Edwardson Sound, and the line of junction between them and the granites passes diagonally across Cunaris Sound to Last Cove in Long Sound, which latter, the boundary-line between the two rocks, also crosses diagonally, reaching the eastern shore of the Sound at a point some two miles higher up the Sound. Schistose quartz is abundant in this formation ; such quartz having often imbedded plates of mica, usually of a black or brown colour (probably biotite). This schistose area has been in places more or less prospected for gold, which, however, does not seem to occur in paying quantities either as alluvial gold or in the reef matrices. However, of this part of the district it may be said that it has received as yet very little prospecting, the extent of the country considered. To the westward of the auriferous belt of Silurian rocks, an area of coal-bearing rocks stretches along the coast-line, the greatest breadth of which is along the line of section between the foot of the gorge of the "Wilson River and the sea at Windsor Point. The greater part of Coal Island shows the presence of these rocks underlying glacier detritus and more modern auriferous gravels derived from the latter. The auriferous drifts of the district are not varied, being glacier moramic drifts, and concentrated results from the same by the action of the sea, and the ordinary gravels of streams, such as Wilson River, and finally the sands of the sea-beach. Alluvial mining at the present time is, over the whole field, in a languishing condition. On Coal Island there are more men engaged in this form of mining than at any other locality, and could a plentiful supply of water be stored in the higher part of the island and utilised at lower levels, where the auriferous gravels lie, there might here be a revival of mining. On Te Whara Beach, and at Gulches Head, the value of the gold-bearing areas have yet to be demonstrated. During the latter part of the season Woodville, the Upper Tiraumea, and Maunceville were visited, in connection with reported discoveries of jet or coal at these places or in their vicinity. Details of these visits will be found in the special reports which follow. I have, &c, The Under-Secretary of Mines, Wellington. Alex. McKay, Mining Geologist.

THE GEOLOGY OF THE AORERE VALLEY, COLLINGWOOD COUNTY, NELSON. Report by Alexander McKay, F.G.S., Mining Geologist. Sir _ 12th June, 1896. Between the Ist and 20th November last I made, as directed, various examinations in c district of the Aorere Valley, Collingwood County, Nelson ; on the geology of which part of the Country I have the honour to supply the following report. The Under-Secretary of Mines, Wellington. Alex. McKay.

REPORT. Introduction. That part of the north-west district of Nelson, which includes the Aorere Valley and the district around Collingwood, is of great interest geologically. It is rich also in useful minerals, and has yielded many varieties, rare or not elsewhere found in New Zealand, and it has the undoubted claim to be regarded as the first goldfield discovered on the Middle (or South) Island. Dr. Yon Hochstetter visited the Aorere goldfield in August, 1859, two years after the first discovery of gold at Lightband's Gully, and subsequently he gave the results of his observations in his great work on New Zealand, from the English edition of which, as the work is now rare, I have thought fit in this place to make the following extract: —