a—9.

46

from their lithological character and condition, there is little doubt that the rocks belong to the Carboniferous period and the Maitai series of the Geological Survey classification, any possible doubt in the matter being whether tbey may not be of Permian or Triassic age. Permian deposits not being known in the Auckland District of the North Island, and the rocks thus to be co-related not resembling the Permian deposits of Nelson or Southland, this theory may be disregarded. As to their being of Triassic age, the evidence is of the same kind, but stronger. There are in them no granity or porphyritic conglomerates which are elsewhere met with in connection with Triassic strata, and the remarkable scarcity of fossils in the older sediments of the Peninsula agrees with the general character of the Maitai series, and is strongly opposed to the idea that they are of Permian or Triassic date, these formations being almost everywhere, even to their coarse sandstones and grits, abundantly fossiliferous. Sometimes these breccia slates have been referred to the Te Anau series of the Geological Survey—a series of rocks which immediately underlies the Maitai rocks—but there is no close resemblance between the two, and on the whole it is as near the truth as may be; and the error cannot be great in placing these older rocks of the Cape Colville Peninsula as representing the Maitai series, and of being of Carboniferous age. Metalliferous Deposits of the Slate Formations. —The massive cherty or hornstone reefs of the Cabbage Bay district yield traces of gold, but not in quantities sufficient to pay the cost of working the reefs, and in a consideration of the mineral wealth of the formation these may be disregarded. At places where the yet overlying volcanic rocks are not distant, outcrops of massive or crystallized quartz are found, and these contain gold that sometimes would pay for working, providing the containing reefs were thicker than they are. Prospecting has been carried on in Dutchman's Gully in the Upper Valley of the Umangawha, and in the slate hills on the west side of the valley opposite Mr. Evans's farm, and some test samples have been taken from the massive hornstone reefs that skirt the lower slopes of the range on the east side of the Umangawha Valley, but the results generally have been unsatisfactory. So that for the present it may be said that in the district of Cabbage Bay and the northern part of the Peninsula gold-mining in the slate formation has not been nor is it likely to prove successful; yet discoveries may be made revealing the presence of paying deposits. A vein of copper-ore is known to occur on the western slope of Moehau. This was prospected many years ago, but has not received any attention during the recent revival in mining. The locality was not visited by me, and Mr. Park tells me that the copper-ore occurs in connection with volcanic rocks, which, on this part of the coast-line, appear mostly as intrusive masses flanking and rising into the mass of the mountain. In the Kennedy Bay district no reefs were observed in connection with the slates, and nothing could be learned from miners and prospectors leading to the supposition that such did occur. However, as the slates appear not distant from where reefs are being worked or prospected within the volconic country, it is not improbable that the reefs found, or others to be found, may be traced into the slates underlying or horizontally not far distant; and were it not that, with the exception of the Kuaotunu field, all mining in the slate country has proved of an unremunerative character, the vicinity of the slates would be regarded as a favourable indication. Mining in the slates in the Tokatea, Success, and Tiki Ranges has been carried on, on and off, for a great number of years, and during the past summer was vigorously prosecuted in the Tokatea Mine, and prospecting was carried on in slates at the Tiki and in the Matawai, but, so far as I could learn, with no very encouraging results. On the Tokatea Hill the Tokatea Reef has been followed down through the overlying volcanic rocks into the slates and felsite tuffs that underlie, and in the slate country has been worked and prospected to a further depth of nearly 500 ft. The reef has continued to the lowest level reached, and can hardly be said to have lessened in thickness ; neither has gold been absent, but on the whole it does not appear that these lower workings in slate have been successfully carried on. At the Tiki, gold-mining has also been carried on in the slate country in the Golden Belt and other claims, for a time hopefully, though eventually without sufficient remuneration. Even now prospecting is being carried on in other parts of the slate country in that neighbourhood, but there are no reports to hand that this is being done with a sufficiency of reward. A little further to the north, on and near Aitken's freehold, gold-mining is being prosecuted in the lowest beds of the Thames-Tokatea group with fair prospects of success, but there any workings lower than those of a shallow and prospecting character must be carried on in slate country, and there is consequent uncertainty of results and as to the productive character of the lodes when they are followed downwards into the slates. In the Manaia Valley several mining ventures have been carried on during the past two years, all of them in slates, and all of them with some doubt as to their ultimate success. In the case of the Golden Hill and some adjacent claims, situated in the valley of a western tributary of the Manaia, these appear to be in a narrow belt of volcanic country, probably a huge dyke decomposed to the condition of the sandstone of the miner, but the adjacent claims to the north, the Golden Hill Extended and others, are again in slate country, and not in a very flourishing condition. At Tapu Creek the Little Jessie seems to be the only mine working in slate, the hope being still entertained that the gold-bearing reefs found in the volcanic rocks, or in the slates near the junction of these with the volcanic rocks, will continue in depth, and prove remunerative. On the west side of the Peninsula gold-mining in the slate country, it has to be confessed, has not been successfully carried on. And now mining-men are beginning to regard the slate as a kind of Farewell rock, and to avoid it accordingly. Theoretically there is no reason why it should be so regarded, and practically in the experience of the past, and over other mining districts even within New Zealand, the slates of the Carboniferous period prove their capacity to carry numerous and rich reefs of auriferous quartz. In this respect the rocks of the same age seem to fail on the west side of the Cape Colville Peninsula; but it would be wrong to arrive at a hasty and premature conclusion in that respect, since in but few instances have the slates been proved to any great depth from the surface or their contact with the overlying volcanic rock.