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copper pyrites, peacock copper, blue and green carbonates of copper, black 

 oxide of copper, native copper, galena, Dufrenoysite and iron pyrites, but not 

 in large quantities. 



" The lode which has been worked for copper for some time at Mine Bay, 

 and which now goes by the name of the ' Otea Company's Copper Mine,' is 

 an old fissure in the slate rocks, filled up with angular debris of slate and 

 diorite of all sizes, from that of a walnut or less, to blocks weighing more than 

 a ton. These blocks are cemented together by a matrix that is sometimes 

 siliceous, and at others felspathic, and it is in this cement or matrix that 

 the copper ore occurs. ~No lead is found in this lode. 



" The fissure runs in a nearly north and south direction across the neck of 

 the small peninsula called Miner's Head. This neck is about 200 yards across. 

 The lode is about 25 feet in breadth at the adit level, which is only a few feet 

 above the sea, and expands to about 40 feet at 1 4 fathoms above adit, and this 

 breadth it keeps pretty regularly until it reaches the top of the hill in which 

 it is situated, and which I estimate to be about 200 feet above adit. I was 

 informed by one of the miners who helped to sink the shaft, that at 12 fathoms 

 below adit the lode was only 9 feet through ; it is therefore probable that the 

 fissure dies out altogether at about 20 fathoms below adit. It is, of course, 

 possible that this fissure may be continued downwards indefinitely ; but there 

 is no evidence of a fault or slide having taken place, and the facts of its 

 original gaping character, and its constantly decreasing breadth as it gets 

 deeper, incline me to the opinion that it is merely a superficial crack. The 

 fact of the lode containing blocks of diorite shows that the dykes were in 

 existence before the fissure was formed, and that therefore they are not the 

 cause of the lode being charged with copper." 



The mine was first worked in 1845, by Messrs. Abercrombie and Sydney ; 

 the ore being a bright yellow sulphide, containing fifteen to sixteen per 

 cent, of metallic copper. The first proprietors worked it for several years, and 

 were then succeeded by Messrs. Whittaker and Heale ; then by Messrs. Ninnis 

 and Rowe ; and lastly by the Great Barrier Company. The works were 

 then suspended, in 1861, but in 1867 they were again reopened by the Otea 

 Copper Mining Company. 



The total quantity of ore mined has been 2,323 tons, the aggregate sales 

 realizing upwards of £30,000. In order to get this ore, Captain Hutton esti- 

 mates that aboxit 3200 cubic fathoms of vein-stuff have been excavated, which 

 would give a yield of nearly three-quarters of a ton of ore to the cubic fathom ; 

 and that about 3800 cubic fathoms remain to be got above the present adit, 

 which will probably yield 2900 tons of ore dressed to fifteen per cent. If my 

 opinion as to the lode dying out about twenty fathoms below adit be correct, it 

 will follow that not more than 4000 cubic fathoms can be got in this direction, 

 which would yield about 3000 tons of ore, making a total of about 5900 tons 

 of ore still remaining in the mine. 



Copper ore was also discovered at Whangapara, in a more northerly 

 locality of the same island, but no regular mine was opened there. 



Nine miles north of Mongonui, in the promontory that forms the northern 

 boundary of Doubtless Bay, copper was discovered, and partly worked, by 

 Mr. Brodie, about the year 1849. 



The peninsula consists, in great part, of porphyritic Trachyte, and Diorite 

 slates. At the copper mine the cliffs are 300 feet high, and the few confined 

 bays at their base are almost inaccessible. 



Here a mass of Breccia Conglomerate abuts against a dyke of hard black 

 Diorite. The Breccia consists of a chloritic matrix, with carbonite of lime, 

 and contains large blocks of Trachyte, and quartz Porphyry. Interspersed are 

 masses of sulphide of iron and copper, and also pure metallic copper. " Cop- 



