T A N E 30, 1984

M I N E R A L E X P L O R A T I O N O N C O P P E R M I N E I S L A N D 1849-1969: A N H I S T O R I C A L R E V I E W

by P.R. Moore New Zealand Geological Survey, P.O. Box 30368, Lower Hutt

S U M M A R Y

Mineral exploration on Coppermine Island spans a period of 120 years, from 1849 to 1969. Attempts were made in 1849, and again in 1898—9, to mine copper on a small scale, but operations were completely .unsuccessful. Events surrounding the early mining efforts are reviewed, and some of the old workings described.

A second, controversial, period of mineral exploration began in 1965, culminating in a drilling programme in December 1968—January 1969 which showed that copper deposits on the island were not an economic prospect. A brief account of activities over the 1965—1969 period is presented, along with a summary of the geological investigations undertaken.

INTRODUCTION

In 1965 Coppermine Island became the subject of bitter controversy when an international mining company, Conzinc Rio Tinto of Australia, applied for permission to undertake a mineral exploration programme on what was then a wildlife refuge (gazetted in 1929). The debate over exploitation versus conservation continued until early 1969 when it was established by drilling that copper deposits on the island were not an economic prospect at existing prices. Just 70 years earlier, others had come to the same conclusion. Efforts to exploit Coppermine's mineral reserves began as early as 1849, but it was 1899 before any significant attempt was made to extract the copper ore, and that soon proved a commercial failure. Nevertheless, the early mining and later mineral exploration phase form a very important part of the history of Coppermine Island, a history which to date has not been well-documented.

Coppermine Island was visited by the writer, and some of the old workings briefly examined, during the Offshore Islands Research Group expedition to the Chickens Islands in December 1981—January 1982 (Fig. 1 and 2). However, the preparation of this review has relied on many sources of information, including an unpublished manuscript by Dr R.R. Brooks of Massey University. Some historical notes on the Chicken Islands are provided by Skegg (1965), and a more complete account of the early history of Coppermine Island is presented in Moore and Brooks (in prep.).

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l ine of s u r v e y

9 , , , , 5 0 0 m 1 1 1 1 1 1 C u a n o m a l y ( > 1 0 0 0 p p m )

xxx m i n e r a l i s e d o u t c r o p

Fig. 1. Map of Coppermine and eastern Whatupuke Islands showing the location of old workings, drillhole sites, and area covered by soil surveys. Data from Thompson and Wodzicki (1967) and Johnston (1969). Note that 'Mackay Point' is used here in preference to 'McKay Point' (see text).

E A R L Y M I N I N G A T T E M P T S : 1849-1899

The Chickens Islands are reputed to have been purchased from their Maori owners in March 1845 by Joel Samuel Polack, and in 'The New Zealander' of 18 October 1845 he cautioned 'all persons from cutting firewood, removing soil or minerals therefrom, or in anyway trespassing on the said islands'. Unfortunately the Governor of New Zealand at the time, Sir George Grey, did not recognise Polack's claim to the islands and in 1849 the following notice appeared in the 'New Zealand Government Gazette' (18 July 1849);

'His Excellency the Governor-in-Chief directs it to be

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notified for general information, that a lease for rnining purposes, bearing date the 23rd June, 1849, has been granted to Isaac Merrick of Auckland for the term of twenty-one years, of all that Island known as and being the north-eastern Island of Moro Tiri (sic), or the group of Islands known as the Hen and Chickens' By His Excellency's Command Andrew Sinclair, Colonial Secretary.

Isaac Merrick was something of a pioneer miner in the Auckland district, having attempted to exploit the copper ore at Miners Head (Great Barrier Island) and on Kawau Island, and in 1844 contracted to mine manganese on Waiheke Island. In 1847 Merrick, with the help of another man, built the schooner Providence and later sailed to Coppermine Island. Twenty tons of copper ore was landed at Auckland on 17 November 1849, then sent to England, but Merrick apparently never heard whether the ship or its cargo arrived. The ore presumably came from the adit at Merrick Bay (Fig. 2a, 3).

Nothing further is known of Isaac Merrick's activities until February 1852, when a policeman named Marsh announced that he had found gold on Waiheke Island. The events following this disclosure are somewhat confused but it seems the gold-bearing samples exhibited by Marsh were actually obtained by Merrick, although not from Waiheke. After much speculation, in March 1852 a committee went by the steamer Governor Wynyard to the Hen and Chickens Group and collected a number of 'soil' samples to test Marsh's claims. Apparently the party also included a geologist from Kawau Island, a M r Percy of the Resident Magistrates office, and two policemen (Skegg 1965). However, even before any results were known 'The Southern Cross' (13 March 1852) predicted, quite correctly, that there was 'no person yet entitled to claim the reward that has been offered for the discovery of 'an available Gold Field' in the Province of New Ulster'. A sum of 100 pounds had been offered for such a discovery.

The incident became known as the 'Waiheke Gold Hoax'. Where the gold-bearing samples really came from was apparently never established, and exactly who was responsible for perpetrating the hoax remains uncertain.

In 1864 the Chickens Islands were granted to Robert Thompson, and in 1882 they apparently belonged to William Grahame, who later sold them to the Crown. Evidently there was little interest in Coppermine Island itself until 1898, when the following brief statement appeared in the New Zealand Mines Record (Anon. 1898, p. 163):

'Copper exists in the Morotiri (sic) Group. A n application for a grant of 250 pounds towards cost of putting in a drive on No. 3 Island, from M r J .W.

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S o u t h

valley

Fig. 2. Sketch plans of (a) the old 'mine' at the south end of Merrick Bay, and (b) adits on a spur above Mackay Point. A smaller adit (4-5 m long) is situated about 20 m further down the spur, and Weissberg (1967, p. 5) refers to a '10 ft drive' to the west.

Mackay and Dr G.T. Girdler, who state that they have spent 500 pounds in prospecting and opening up reefs, has been refused, as there are no regulations under which assistance towards mining for copper can be granted.'

After this initial set-back, Mackay moved towards establishing a company - the Marotiri Copper Syndicate - to exploit the copper deposits on Coppermine Island. Progress of the company and its operations was reported in the 'New Zealand Herald' of 1899 (some of the following extracts have been severely edited by the writer):

June 2nd 'It is intended to commence mining

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operations on the Marotiri copper property, situated on the Hen and Chickens. The copper deposit to be operated upon is on Mona Island, and it is intended to drive right through the hill and thoroughly test the property. The requisite capital for the prosecution of mining operations has been subscribed, and M r J .W. Mackay, who is interested in the property, states that work will shortly be commenced.' June 8th ' A preliminary meeting of shareholders in the Marotiri Copper Syndicate (Limited) was held yesterday at the office of M r A . Hanna. After some discussion as to the disposal of shares, it was resolved that a limited-liability company be formed, with 100 000 shares at 6d each, 75 000 to be fully paid up, and to be allotted to vendors in payment of their interest in the property, and 25 000 contributing shares, the calls to be 2d on application and afterwards not more than Id per month ... The following were appointed directors: Messrs H.A. Gordon, J . McCombie, Ross A.S. Allom, N . Niccol, Mays, and Dr Girdler... ' June 16th 'It is understood that the Marotiri Copper Company intend to conduct mining operations on their property... as soon as possible. M r J .W. Mackay, through whose exertions the capital for the development of the property has been obtained, intends proceeding to the island in a few days, and will take with him sufficient numbers of men to properly work the mine. It is probable that the work to be undertaken will be the extension of the crosscut through the formation.'

The 'crosscut' mentioned may refer to part of the workings above Mackay Point* (Fig. 1,2b). According to Skegg (1965, p. 94) three men worked on the island, and there was a 7 . 5 m x 3 . 5 m corrugated iron hut in the 'southern bay' (Merrick Bay ?).

July 8th 'Under the superintendence of M r John McCombie, Managing Director of the company ... work is proceeding apace. It is intended to drive through the hill, so that the quality of the copper ore at a depth will be ascertained, and from this level about 500 ft of backs will be obtained.'

Footnote Mr A . H . Pickmere ('Northern Advocate' September 1969) proposed that the headland be

called McKay Point after Norman George McKay, but it seems more appropriate to name it Mackay Point, after J.W. Mackay. This name has recently been approved by the New Zealand Geographic Board.

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July 13th 'Some of the directors of the Marotiri Copper Company ... have left on a visit of inspection to the property. July 14th 'It is rumoured that the development work now proceeding on this property at the Hen and Chickens is resulting even more satisfactorily than was anticipated, and that the formation has been found to contain gold in small quantities. Nothing definite is yet known as to the nature or value of the find, and no official information is available as to the actual result of development work, so that we are not in a position to in any way vouch for the accuracy of the rumour.' July 17th 'The directors and others who last week paid a visit to the Marotiri copper mine on Mona Island ... returned to Auckland on Saturday. A quantity of the formation was taken out and brought back, and will be tested for gold, which it is supposed exists in the stone. A report upon the result of the development will be submitted by the Managing Director, M r John McCombie.' July 20th 'It was recently reported that gold had been discovered in the formation (containing copper) obtained from the Marotiri Company's mine on Mona Island. M r J . McCombie who recently visited the mine, reports that one of the samples assayed by Messrs Pond and Maclaurin, showed slight traces of gold and silver, and the other samples no trace of either, and that so far as operations are concerned, are commercially valueless. It was doubtful whether the deposit would ever be found to contain gold in payable quantities. As to the copper mine, M r McCombie advocated working the veins either hillwards or under foot, and anticipates that good ore would be found at a comparative small amount of sinking.' September 7th 'Some specimens of stone from the Marotiri copper mine... have been brought to Auckland by M r J.W. Mackay, under whose superintendence work is proceeding. The stone is heavily mineralised, and contains large quantities of copper pyrites.

Development work over the period June to September 1899 may have been concentrated on extension of the adits above Mackay Point (Fig. 2b), which were probably initiated by Mackay himself in 1898. Just how

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much work was carried out on the 'mine' at Merrick Bay (almost certainly begun by Merrick in 1849) is difficult to assess, but considering its limited extent possibly the only significant development was the excavation of a shaft (Fig. 2a). There is some suggestion from the 'New Zealand Herald' report of 20 July that this could have been started in August 1899.

On 24 November 1899 the 'New Zealand Herald' reported that a special meeting of the Marotiri Copper Syndicate had passed a resolution to authorise the directors to 'sell the property of the company upon such terms and conditions in all things as they think fit.' Thus ended the first serious attempt to exploit Coppermine's mineral deposits; a further attempt would not be made for another 70 years.

As for Mackay, his association with Coppermine lasted a little longer -he was left stranded on the island for several months about the time the Marotiri Copper Syndicate collapsed. Presumably he continued working on some of the abandoned adits.

T H E E X P L O R A T I O N PERIOD: 1965-1969

Phase one: 1965—1967 By the 1960s people were much more aware of the biological value of

offshore islands, and when Conzinc Rio Tinto of Australia L td applied, in late 1965, to carry out an intensive mineral exploration programme on Coppermine Island it precipitated a vigorous public debate. The Government did not approve the company's application, and instead the Nature Conservation Council recommended that prospecting should be undertaken by DSIR personnel. Two geological surveys were subsequently carried out, in February 1966 and February—March 1967.

The first Geological Survey party, consisting of B . N . Thompson, A . Wodzicki and L.O. Kermode, arrived at Coppermine Island on 5 February 1966 and remained there until 11 February. Preliminary soil sampling and collection of mineralised rock samples was undertaken during this period (Fig. 4). The second party, which included two additional members - G. Bishop and geochemist B.G. Weissberg -visited Coppermine from 25 February to 4 March 1967. Detailed soil sampling was carried out by Dr Weissberg, and other geological investigations completed (Thompson and Wodzicki 1967, Wodzicki and Thompson 1970).

Only two areas of significant copper mineralisation were identified by the geologists - the section between Merrick Bay and Coppermine Point (Fig. 1, 5), and 400 m of coastline west of Maire Bay ('Ngapona Bay' in the 1967 report). It was estimated that together these areas 'almost certainly' contained about 500 000 tonnes of mineralised rock averaging 0.5% Cu. Dr Weissberg's soil survey over the western part of Coppermine also indicated that there was an area of approximately 4 hectares containing anomalously high (greater than 400 ppm) total

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Fig. 3. Entrance to the adit ('mine') at the south end of Merrick Bay in January 1982.

copper concentrations. From data obtained during the two geological surveys Thompson and Wodzicki (1967) concluded there was possibly an economic copper deposit on Coppermine Island and recommended drilling and further soil sampling.

Phase two: 1967—1969 On 8 September 1967 C R A Exploration Pty Ltd , a subsidiary of

Conzinc Rio Tinto, applied to the Warden's Court in Auckland for a mineral prospecting warrant covering both Coppermine and Whatupuke islands. Proceedings were adjourned, and later in the month three petitions were presented to Parliament opposing commercial exploitation of Coppermine's mineral deposits. On 27 October 1967 the Labour and Mining Committee reported to the House, expressing the opinion that the first stage of prospecting should be allowed to proceed.

The hearing of CRA's application was adjourned 11 times over the ensuing months and it was not until 5 August 1968 that Government approval was announced by the Minister of Lands. C R A finally received

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Fig. 4. DSIR geologists A . Wodzicki and L.O. Kermode (right) collecting mineralised rock samples between Merrick Bay and Coppermine Point. Photo: B.N. Thompson.

a mineral prospecting licence on 30 October 1968, subject to certain conditions designed to restrict damage to the flora and fauna to a bare minimum. Prospecting was to be limited to a maximum of 6 drillholes on the western side of Coppermine, and surface investigations on the rest of Coppermine and on Whatupuke.

On 31 October it was announced that three holes would be drilled to 180 m on the western side of the island in December, and CRA ' s driller M r R. Read made a preliminary visit to Coppermine on 16 November 1968.

The drilling team of 15 men landed on the island about mid December. Three of the holes were drilled between 170 m and 340 m apart, in a triangular pattern, to depths of 90,120 and 150 m (Fig. 1). A fourth hole (Hole 3) was sited on the same spot as No. 1, but drilled at an angle of 45° in a westerly direction to 180 m. Drilling was completed on 20 or 23 January 1969, and all equipment removed from the island the following day. About 1 300 kg of core samples were subsequently sent to Wellington for analysis.

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dr i l l s i t e

Fig. 5. Aerial view of the western end of Coppermine Island showing the approximate position of old workings. The narrow shore platform and coastal cliff between Merrick Bay and Coppermine Point reveals numerous mineralised veins. The bare patch on the ridge crest between Merrick Bay and Maire Bay (arrowed) is probably the site of drillholes 1 and 3 (Fig. 1). Photo: Lloyd Homer, New Zealand Geological Survey.

A reconnaissance soil survey of Coppermine and eastern Whatupuke islands was also completed by C R A geologist W . H . Johnston in January, involving hand coring to an average depth of 2 m and sampling of the basal soil layer. However, no further anomalous mineralised areas were identified.

The drilling programme indicated that overall copper values were very low - 0.03% to 0.11% Cu - and that grade tended to decrease with depth. Not surprisingly, Johnston (1969) concluded that the results did not 'provide sufficient encouragement for further prospecting'. On 25 March 1969 the Minister of Mines announced that C R A was surrendering its prospecting warrant, and was quoted as saying: 'The negative results (of CRA 's drilling) ensure that there will now be no future interference with the wildlife of the islands from mineral exploration, ('New Zealand Herald'? 26 March).

If there is one beneficial aspect arising from the mineral exploration on Coppermine it is that the vast amount of geochemical data obtained now provides a useful basis for a variety of scientific studies. A Massey University team took advantage of this in January 1972 when they

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carried out a biogeochemical survey to determine whether copper anomalies were reflected in certain plants (Yates et al 1974).

Today, Isaac Merrick, Mackay, the Marotiri Copper Syndicate and C R A all form part of the historical wealth of Coppermine Island.

A C K N O W L E D G E M E N T S

I am particularly grateful to Dr R.R. Brooks for use of his unpublished manuscript on the early history of Coppermine Island, and Mr B.N. Thompson for providing information and photographs. I also thank Messrs L.O. Kermode, A . N . Skelton, F.D. Arnott and W.A . Heap for their assistance. The paper was critically reviewed by Dr Brooks and Mr Thompson, and typed by Fay Tonks.

R E F E R E N C E S

Anonymous 1898: Notes and comments. New Zealand Mines Record 2(4): 163. Johnston, W . H . 1969: Copper-molybdenum mineralisation, Coppermine Island, New

Zealand. Unpublished report, C R A Exploration Pty Ltd. New Zealand Geological Survey Mineral Exploration Report MR 191.

Thompson, B.N. & Wodzicki, A . 1967: Geology and mineralisation of Coppermine Island (with appendix on soil geochemistry by B .G . Weissberg). New Zealand Geological Survey Report 25.

Weissberg, B .G . 1967: Soil geochemistry at Coppermine Island. In: Thompson, B . N . & Wodzicki, A . Geology and mineralisation of Coppermine Island. New Zealand Geological Survey Report 25.

Wodzicki, A . & Thompson, B .N. 1970: The geology and mineralisation of Coppermine Island. New Zealand Journal of Geology and Geophysics 13:631-646.

Yates, T . E . ; Brooks, R.R. & Boswell, C.R. 1974: Biogeochemical exploration at Coppermine Island, New Zealand. New Zealand Journal of Science 17:151-159.

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