From the beds b. and c. a quantity of ore was excavated and shipped to 

 London, where it was sold for £7 per ton. 



"Within a few months a copper lode was accidentally found cropping out, 

 a large sample of which, taken at random, realized £15 to £20 per ton. This 

 led to regular mining operations, and in 1846 a well-defined lode of copper ore 

 was opened up, twelve feet in width, running N.E. and S.W., with a dip or 

 underlay, of three feet to the fathom. The ore consisted of blue and yellow 

 sulphurets, containing an average of twelve per cent, of copper. Several 

 shipments of the ore were made, in the raw state, but had to be abandoned on 

 account of the danger of fire, from the heat generated by the decomposition 

 which the ore underwent in the holds of the vessels. 



Works were then erected for the reduction of the crude ore to the state 

 of reguhts, by roasting, in which condition it was a safe article for shipment. 



The situation of the smelting works, which were most expensively con- 

 structed, was in Bon Accord harbour, where there is deep water close to the 

 wharves. 



The first four years workings realized upwards of £60,000, but the 

 pumping machinery was deficient, so that the mine had to be abandoned for 

 eighteen months, till a large Cornish engine was obtained. This effectually 

 kept the water down, and the mine was extended to a vertical depth of 

 35 fathoms, with a horizontal extent of 150 fathoms, on a lode averaging 

 6 feet in width, and consisting of a massive gangue that contained thirty per 

 cent, of copper ore, and the same of iron ore, intermixed with dark green 

 chloritic clay. The lode lies between green slates, containing grains of 

 metallic copper, and stained with salts of copper, and a hanging wall of 

 indurated chert. 



The mine appears never to have been worked out, but was abandoned, 

 partly owing to complications respecting the proprietorship, but mainly owing 

 to the superior attractions of the Californian and Australian gold fields at that 

 time. The particular lode that was worked is on a headland on the south side 

 of the island. It was lost in tracing it inland, to the north, but there is good 

 reason to believe that this headland is onry a dislocated mass, formed more in 

 the manner of a landslip than a structural fault, and that there may have been 

 a displacement of the lode.* 



The Gr*eat Barrier Island, on which have been the most extensive copper 

 mining works in New Zealand, is about twenty-four miles long. A central 

 chain runs through the island, throwing off spurs on either side, rising to an 

 extreme elevation of 2330 feet, and maintaining an average height of about a 

 thousand feet throughout its length. 



The greater part of the island is composed of volcanic (Trachytic) rocks, 

 resting on sub-metamorphic slates and sandstones, of the same kind as at 

 Kawau. These slaty rocks are, in several places, but especially at Mine Bay, 

 cut by intrusive dykes of quartz porphyry, consisting of a felspathic paste 

 containing grains of fine quartz. Felstone, which may be considered as the 

 same rock devoid of quartz, Diorite, which is a mixture of Felspar and the 

 fusible mineral Hornblende, and, lastly, a true dyke granite, containing quartz, 

 Mica and Felspar. In these rocks we have representations of the crystalline 

 metauiorphic formations, which are so abundant in the South Island, brought 

 to the surface as dykes. 



Captain Hutton thus describes the position of the mines [Geological 

 Reports, 1869, p. 4] :— 



" Some of the dykes of Diorite and Felstone contain, near Mine Bay, 



* See "Geological Reports, 1869," p. 45, for map, and description of Kawau, by 

 author. 



