Plants of the mistletoe family or Loranthaceae are found mainly in tropical countries but some occur in temperate regions of both hemispheres. They are all partial parasites – they depend partly on other plants, known as the hosts, for their supply of water and mineral salts but have green leaves in which food is manufactured. There are few more showy sights in New Zealand than the brilliant scarlet flowers of Elytranthe colensoi or E. tetrapetala perched high up in the sombre green southern beech (Nothofagus).

Altogether there are four genera of the mistletoe family in New Zealand. Korthalsella has two species, both small and leafless and with minute flowers. They are not easy to find and parasitise such shrubs as Coprosma spp., Dracophyllum spp., tea tree, etc. Elytranthe has 50 species altogether, spread throughout India, Malaya, Polynesia, and Australia. There are four species in New Zealand and all are endemic. Besides the two scarlet-flowered ones given above, the species E. flavida has yellow flowers. It is found on southern beech trees. Leaves are ovate to elliptic and, according to the species, vary from one half to 3 in. long.

Two other genera have each a single species in this country. Loranthus is a fairly large tropical and subtropical genus of some 550 species. The one New Zealand plant, L. micranthus, is endemic. It has oblong leaves usually about 2 in. long, small flowers, and small yellowish berries which are readily eaten by birds. It is widespread throughout the country on a number of hosts, mainly native shrubs and some introduced trees, including fruit trees. Tupeia antarctica is the only species in the genus and is endemic to New Zealand. It is found as a parasite mainly on Neopanax and, in the north, on tarata, Pittosporum eugenioides.

by Alec Lindsay Poole, M.SC., B.FOR.SC., F.R.S.N.Z., Director-General of Forests, Wellington.

North German Missionary Society

In July 1843 four Lutheran missionaries arrived at Nelson. J. F. H. Wohlers settled on Ruapuke Island in Foveaux Strait in 1844, while J. F. Riemenschneider established a station at Motokaramu (Mokau) in 1844, moving to Warea (Taranaki) in 1846. As little financial support was sent, these two and several others who came to assist them later joined other missions.

Presbyterian

The Rev. James Duncan of the Reformed Church of Scotland was sent as a missionary to the Manawatu district in 1844. A small mission was maintained there and in the Rangitikei district until 1894. In 1895 a new mission was commenced at Taupo and, later, work was undertaken at Taumarunui, Nuhaka, and in the Urewera.

Others

The census reports show that most of the other Christian denominations are today engaged in mission work among the Maoris.

by Nancy Gaynor Falkner, M.A., DIP.N.Z.L.S., formerly Research Assistant, Internal Affairs Department, Wellington.

• The History of the Church Missionary Society in New Zealand, Stock, E. (1935)
• The Life and Times of Bishop Pompallier, Keys, L. (1957)
• Sketch of the Work of the Catholic Church for the Last Half Century in the Archdiocese of Wellington (1887)
• Proceedings 1941—, Wesley Historical Society.

In 1836 the mission of Oceania was entrusted to the Society of Mary (Marists), and Jean-Baptiste François Pompallier appointed Vicar Apostolic. He arrived at Hokianga on 10 January 1838 with one priest, one brother, a small supply of goods, and almost no money. He established a station at Papakawau and some converts were made, but most of the Maoris round Hokianga were already Methodists and openly hostile. In the following year more priests and catechists arrived bringing money and a printing press. By 1840 the headquarters of the mission had been shifted to Kororareka, and Maoris had been baptised at the Bay of Islands, Hokianga, Kaipara, Whangaroa, and Mangonui.

1840–70

The Catholic mission was officially under the protection of the French Government and was visited by French naval vessels. This caused some hostility towards it from Governors Hobson and FitzRoy, as well as the Protestant missionaries. Pompallier, however, always tried to remain aloof from politics. His method of conversion was to visit as many villages as possible and then to send a more or less itinerant priest into the district and, finally, to erect the buildings of a permanent station. Bishop Pompallier himself made three voyages round the east coasts of the North and South Islands in 1840 and 1841 before setting out on a visit to his island missions. A report to the Sacred Congregation of Propaganda in 1841 showed 164 tribes as Catholic, 1,000 baptised neophytes, and about 45,000 catechumens, but it is clear that most of these Maoris had had only the instruction given by the Bishop or a priest on a brief visit, and later estimates by Marist fathers are very much lower. In nearly all districts Anglican or Wesleyan missionaries were already established, and acrimonious public debates confused further the Maoris' ideas of Christianity.

During 1840 stations had been consecrated at Whangaroa, Tauranga, Kaipara, and Akaroa, where French colonists were expected. As further priests and brothers arrived, stations were established at Rangiaowhia (Waikato), Opotiki, Auckland, and Rotorua. No Marist priests came after 1843, and most of those already in New Zealand accompanied Father Viard when he was appointed Bishop of Wellington in 1851. Although Pompallier recruited priests and nuns in Europe between 1846 and 1849 and subsequently opened schools, lack of money, and finally the Maori Wars, brought work to a halt.

In the Wellington diocese there were estimated to be in 1853 about 1,000 Maori Catholics, principally at Hawke's Bay, Wanganui River, and Otaki, but by 1868 all the former missionaries had been transferred to European parishes.

1870

After the Maori Wars, Father James McDonald was for some years practically the only priest on the Maori mission, but he visited from Hokianga to the Waikato. In the 1880s the Mill Hill fathers were invited to conduct the Maori mission in the Auckland diocese. During the following 50 years, stations were re-established in Northland, Bay of Plenty, Waikato, and the King Country, and St. Peter's College, Northcote, was founded for training Maori catechists. In the Wellington diocese only Sister Mary Joseph Aubert at Hawke's Bay was still respected and listened to by the Maoris. At her suggestion a missioner was appointed to Hawke's Bay in 1879. In 1881 this priest, Father Soulas, visited the Wanganui River and shortly afterwards re-established a station there. The Society of Mary began to send out priests again in 1884, and by 1887 there were again estimated to be about 1,000 Maori Catholics at Hawke's Bay, Otaki, and on the Wanganui River. From these small beginnings the Catholic church was rebuilt, and at the 1961 census had 28,656 adherents out of a total Maori population of 167,086.

1823–40

In 1818 Samuel Leigh, a Methodist minister stationed at Sydney, visited New Zealand and on his return to England he proposed to the W.M.S. that he should be sent there as a missionary. He arrived at Rangihoua, the C.M.S. station, in 1822 and with William White, James Stack, and Luke Wade, a layman, who joined him the following year, he established a mission station at Whangaroa in June 1823. Nathaniel Turner and John Hobbs reached Whangaroa in August 1823 with Samuel Marsden, who completed the land purchase at Whangaroa for them, and took Leigh, in ill health, back to New South Wales. On 10 January 1827, “Wesleydale” was attacked during Hongi's raid on the Whangaroa tribes, and the mission station had to be abandoned.

The W.M.S. Instructions to the early missionaries emphasised that they were “to propose the gospel in its simplest and most explicit truths, as an undoubted revelation from God” and to refrain from disputing the superstitions of the natives. They were to learn the language, teach the natives agriculture and some of the useful arts of life, and to cultivate in them habits of labour and industry. They were prohibited from trading and, unlike the members of the C.M.S., they were forbidden to buy land except for the use of the W.M.S.

Within six months of abandoning Whangaroa, Hobbs and Stack returned to Hokianga, and founded a station at Mangungu. Its proximity to the C.M.S. stations brought both advantages and friction. By the 1830s many Maoris were being converted and it was the policy of William White, superintendent of the mission 1830–36, to extend work south into the Waikato, which brought him into conflict with the C.M.S. Stations were commenced at Kawhia and Whaingaroa (Raglan). These were abandoned in 1836 on instructions from the London W.M.S., but were resumed following an agreement on boundaries with the local C.M.S. in October 1838. There were also stations at Kaipara from 1836 and Pakanae (Hokianga) from 1837.

1840–70

The Wesleyans continued their advance down the west coast of the North Island and between 1840 and 1845 stations were founded at Aotea, New Plymouth, Te Kopua (Waipa), Mokau, and Waimate (South Taranaki). At all these places native teachers prepared the way. Stations were also formed at Auckland, Waima (Hokianga), and Wellington, and James Watkin began the first Christian mission in the South Island at Waikouaiti on 16 May 1840. The Maori population of the South Island was small and scattered, but a further station was founded at Port Underwood in December 1840, from which the missionary Samuel Ironside departed after the Wairau disturbance in 1843.

From 1844 when the Rev. Walter Lawry was appointed General Superintendent of Missions, the Wesleyan headquarters were at Auckland. There was a Native Institution for training native teachers at Grafton Road (1845–48) and, later, at Three Kings (1849–69), and a Maori girls' school at Onehunga. There were also village schools attached to some of the stations because both for Anglicans and for Wesleyans it was important that their converts should be able to read the Bible. Under Sir George Grey's governorship the Wesleyans received one-third of the education grant, the Catholics one-sixth and the Anglicans one-half.

In 1846 there were 14 mission stations with 17 missionaries, 345 native helpers, 2,960 church members, and 4,834 children at school. By the time of the Maori Wars there were stations at Mangungu, Waima, and Pakanae on the Hokianga; Tangiteroria and Mangawhare on the Kaipara; Mechanics Bay and Ihumatao at Auckland; Raglan, Kawhia, Aotea, and Te Kopua south of Auckland; Mokau, New Plymouth, and Heretoa in Taranaki; and Port Underwood and Waikouaiti in the South Island.

In 1863 the stations near the Waikato had to be vacated and in 1868 Raglan, Aotea, and Kawhia were combined in one circuit under the Rev. Cort Schnackenberg while Te Kopua was not even a preaching place.

The Wesleyans had assisted in the collection of signatures for the Treaty of Waitangi and they did not, in the following years, criticise Government policy or actions with regard to land buying or the events leading to the Maori Wars as outspokenly as the Anglican missionaries. The Wesleyans feared a war, seeing the destruction of their years of work as an inevitable consequence, and they advised the Maoris not to fight. When war did come the missionaries sent in reports to the Government of Maori activities and intentions, and acted as chaplains to the British troops. The Maoris regarded them as spies and traitors. John Whiteley, a veteran missionary at Taranaki, was murdered by a party of Hauhaus at Whitecliffs in 1869, after which fighting ceased.

1870

Many of the Maoris in North Auckland had remained loyal to their churches but the decline in population and the wandering life necessitated by the principal occupation of gumdigging reduced congregations. One missionary at Hokianga served both Europeans and Maoris for many years. South of Auckland the great reduction in the Wesleyan following had been already noted. In Taranaki, where much of their land had been confiscated, the Maoris congregated at Parihaka round the prophet Te Whiti, avoiding all European contacts. The mission was re-established but the rise of the Ratana movement at Wanganui following the First World War reduced its influence. In the South Island the dwindling Maori centres of population were included in adjacent European circuits. With 12,611 adherents in 1961, the Methodist church did not appear to have regained its original strength among the Maoris.

1814–40

Samuel Marsden, chaplain of the penal settlement at New South Wales, had been impressed by the Maoris he had encountered and when in England in 1807–08, he asked the C.M.S. for missionaries, or failing that, two or three mechanics to go and live among the Maoris, to teach them the simple arts of life and so prepare them for the Gospel. William Hall, a carpenter, and John King, a shoemaker, returned with Marsden. It was not until 1814 that they sailed for the Bay of Islands with Marsden and Thomas Kendall, a schoolmaster. On 25 December Marsden preached the first Christian sermon in New Zealand which Ruatara, a young chief befriended by Marsden, translated for the uncomprehending Maoris.

The Maoris had no organised religion but their lives were regulated in many aspects by tapu (prohibitions relating to sacred persons, places or objects). They had many gods (atua) of varying importance. The God of the missionaries was also classified as an atua and the objection was often to be raised that, although he was undoubtedly powerful, he was the god of Europeans, not of Maoris; or, if he was the god of one tribe, he could not also be the god of their enemies. The gods of the Maoris were feared and placated so that the concept of a merciful and loving God introduced a gentler element into their religion, but the emphasis on punishment for sin after death brought new fears.

By June 1815 the “lay settlers” at Rangihoua numbered 25, but Ruatara, whom Marsden had expected to be the mainstay of the mission, was dead. The Maoris were acquainted with the whalers and traders who called at the Bay of Islands, but the mission settlement had a different moral tone from Kororareka. At first the Maoris helped in clearing land and felling timber; later they wanted only guns, in which the missionaries were forbidden to trade, and they did not care to learn the various trades the settlers could have taught them. Henry Williams observed, some years later, that “in all the efforts to civilise they do not perceive that we have any views beyond that of benefiting ourselves”. As to Christianity, the lay settlers observed the Sabbath, conducted family prayers and spoke to the Maoris of Christianity, as opportunity offered. On a visit to England in 1820, Kendall assisted with giving a written form to the Maori language.

In 1819 John Butler, the first ordained missionary, was stationed at Kerikeri near the principal cultivation grounds of the powerful chief Hongi, whose cannibal feasts filled the missionaries with alarm and disgust. Butler spent much of his time building and farming, but with the arrival of Henry Williams at Paihia in 1823, and his brother William Williams, in 1826, the emphasis shifted to spiritual instruction of the Maoris. It was not until 1825 that the first baptism was made because the missionaries were determined that each convert should understand the catechism thoroughly, make a genuine profession of faith, lead a Christian life, and abandon his old beliefs completely. Other baptisms followed, slowly at first, but with increasing rapidity throughout the 1830s and 1840s. Henry Williams became greatly respected by the Ngapuhi, and through his influence fighting was prevented on several occasions. Missionary influence also resulted in the freeing of slaves and the cessation of cannibalism.

Further missionaries arrived, some ordained, some laymen trained at the C.M.S. Institution at Islington, so that by 1832 at the Bay of Islands there were four priests, 13 laymen, and 12 women. Schools and a farm had been established at Waimate in 1831. Expansion beyond the Bay of Islands now began. Between 1834 and 1840 stations were established at Kaitaia, Thames, Whangaroa, Waikato, Matamata (abandoned during a resurgence of tribal wars in 1836–37), Rotorua, Tauranga, Manukau, and Poverty Bay. Usually the formation of a station consolidated rather than began missionary activity in the district. The mission station customarily consisted of a house for the missionary's family, a schoolroom and chapel, and sleeping quarters for the school children and adult Maoris who were being trained as teachers. A farm and orchard were often attached. From the station the missionary visited regularly, usually on foot, a circuit of villages.

By 1840 much of the Old and New Testaments had been translated by William Williams and Robert Maunsell, and many copies issued from the mission press at Paihia.

1840–70

During these early years the activities of lawless Europeans and land speculators, and the partial collapse of the traditional restraints in Maori society caused most of the missionaries to welcome British annexation. Thus the C.M.S. members persuaded chiefs throughout the country to sign the Treaty of Waitangi.

From 1840 to 1856 missionary influence was at its height. Further stations were opened until practically the whole North Island was covered, and many baptisms were made (including the sons of the notorious chiefs Te Waharoa and Te Rauparaha. In many villages morning and evening prayers and Sunday services were held. The Maoris were also prospering materially. In a number of districts they were producing a steady supply of food for the European settlements and in the Waikato, in particular, they seemed to have become a community of industrious farmers. Bishop Selwyn made long journeys on foot through the North Island, becoming thoroughly acquainted with the work of the missionaries. In the far north, however, Maori prosperity had decreased and, with it, their approval of British government. In Hone Heke's rebellion of 1845 mission property was undamaged, but the missionaries never regained the same influence among the declining population of despondent Maoris. Meanwhile a dispute between Governor Grey and a number of missionaries in the north horrified the C.M.S. in London and resulted in the resignation of several missionaries and the unjustified suspension of Henry Williams until 1854. At Wellington the Maoris disputed the land purchases of the New Zealand Company, and sporadic fighting occurred which ended with the imprisonment of Te Rauparaha in 1846. Until his health broke down in 1844, Octavius Hadfield remained at Otaki, using his not inconsiderable influence for peace.

Under Governor Grey grants were made to Anglicans, Wesleyans, and Catholics to maintain schools, particularly industrial boarding schools similar to that run by Hadfield at Otaki. After 1853 little official interest was displayed and many schools were closed during the Maori Wars.

The missionaries did not generally oppose colonisation, although they were accused of doing so, but they wished the Maori to retain sufficient land to support himself, and in the disputes arising from the Waitara purchase men like Bishop Selwyn and Hadfield wished merely to see justice done. Nor did the C.M.S. missionaries support the King movement which was essentially an expression of Maori nationalism. Their aim had always been to encourage the Maoris to adopt not only Christianity but also their own English middle class morals and manners. Despite their criticisms of the Government, when war came the missionaries aligned themselves with their European compatriots. During the Waikato campaign of 1863–64, John Morgan and other missionaries reported to the Government on Maori affairs.

When the Maoris retired south into the King Country, they were no longer accessible to the missionaries. In 1865 Hauhauism spread to the east coast and resulted in the murder and mutilation of the missionary C. S. Volkner, the narrow escape of T. S. Grace and the abandonment of his station in Poverty Bay by William Williams.

During these troubles certain Maori tribes remained loyal to the Government and to their church, but even among them the enthusiasm of the early years for European ways was greatly reduced.

1870

Bishop Selwyn had delayed many years before ordaining the first Maori priest although he had founded a college at Waimate (moved in 1844 to Auckland) for training candidates. After 1870 ordinations increased and in 1900 there were 69 Maori clergy.

By 1880 the missionaries who had arrived in the 1830s were either dead or past strenuous missionary activity. Negotiations for the withdrawal of the C.M.S. began in 1854 and few men were sent out after this. It was not until 1903 that C.M.S. grants were completely discontinued, and each diocese became responsible for work among its own Maoris. At present Maori clergy serve Maori pastorates and a Maori bishop supervises this work. Various new religions founded by Maori prophets, the Mormons, and certain Christian sects, have from time to time drawn members away from the Anglican church, but during this century it has increased at approximately the same rate as the Maori population. At the 1961 census over 30 per cent of Maoris were returned as Anglicans.

From the religious revival in England during the eighteenth century arose a new interest in overseas missions. The Church Missionary Society, formed by lay and clerical evangelicals in 1799, grew into an influential body sending missionaries to many parts of the world, including New Zealand. The Wesleyan Missionary Society was formed in 1813 and its activities were directly controlled by the English and, after 1855, the Australasian Methodist Conference. Both societies depended on subscriptions from members of missionary associations for financial support. In France missionary activity began to revive about 1815. The missionaries belonged to various religious orders and were under the ultimate control of the Sacred Congregation of Propaganda in Rome, while financial support came largely from the Society for the Propaganda of the Faith, founded at Lyons in 1819.

(Podocarpus ferrugineus).

Miro was known and cherished by the Maoris because of its fleshy covered fruit, about an inch long, on which the native pigeon feeds and fattens. It is a softwood forest tree growing up to 90 ft high and 1 to 3 ft through the bole. The leaves are one-half to three-quarters of an inch long, are linear, and arranged in two rows. The flowers are on separate trees, male in small catkins and the females very small, on the top of short, curved peduncles.

Miro is found in lowland forests throughout North, South, and Stewart Islands. It is a scattered forest tree, the crowns of which join others, like rimu (Dacrydium cupressinum) in forming broken, emergent foliage masses above the general canopy of the broadleaf trees. It is seldom a dominant forest tree, but a small forest – now milled – in the Opawa-Rangitoto area, east Taupo, was composed largely of miro. Scattered regeneration is a frequent occurrence even where adult trees are scarce or apparently absent. This suggests widespread distribution of the seed by birds.

Miro timber closely resembles that of rimu, and it is usually marketed as such. Heartwood is somewhat darker in colour, finer in grain, easily worked, and of exceptional strength.

by Alec Lindsay Poole, M.SC., B.FOR.SC., F.R.S.N.Z., Director-General of Forests, Wellington.

Ground water is a mineral of the greatest importance to New Zealand: for human consumption, for secondary industry, and, in particular, for the primary agricultural industry. Fortunately, the abundant rainfall in most areas and the common presence of gravels, sands, fissured volcanic rocks, and cavernous limestones, afford plentiful supplies of ground water in many areas. Elsewhere lesser quantities are obtained from sandstones, or fractured harder rocks, but in some areas, where only clays and impermeable fine-grained rocks such as mudstones (papa) are within the range of normal drilling, an adequate supply of ground water is not possible. Artesian water is important in the seaward Canterbury Plains, and in the lowlands of the southern North Island. It is, by definition, ground water that occurs naturally under pressure and is usually present in a sloping gravel bed beneath an impermeable clay cover.

Most underground water is of good quality. Some is warm or hot, and hot springs are relatively widespread and are particularly common in the recently active volcanic regions. From Taupo to White Island geysers and hot springs have long implied a possible potential for power development from geothermal steam. Investigations began seriously in 1950, and a 150 mW station, with plans for further development, has been erected at Wairakei. There are hopes that the combined potential at Waiotapu, Orakeikorako, Rotokawa, Tikitere, and Te Kopia may prove to be about three times that of Wairakei.

by David Kear, B.SC.(MINING)(LOND.), A.R.S.M., New Zealand Geological Survey, Otahuhu.

Important minerals in Maori culture included greenstone and obsidian; hard dense rocks for adzes, like the hardened argillite found alongside serpentine in Nelson; and natural pigments, such as black manganese oxides, blue vivianite, or pukepotu (an iron phosphate), and red and yellow ochres – kokowai – (the iron oxides hematite and limonite). More recently, non-metallic minerals of these types, now termed “industrial”, have become increasingly important, and their production and uses are expanding rapidly.

The greatest single output, £10 million worth, is of those materials (crushed rock, gravel, and sand) that are used in the booming constructional industries of roading and building. Similarly widely used bulk materials are clays for brickmaking, crushed limestone for agriculture, and limestone and marl (papa) for cement in the seven New Zealand works. Many handsome local building stones are available – marble, granite and allied rocks, limestone, serpentine, ignimbrite, and many darker volcanic rocks.

Lesser known minerals are perhaps the more interesting, however. Some rhyolitic volcanic rocks of the central North Island, known as “perlites”, have the property of swelling as much as 10 times when heated to about 1000° c. Perlite is used for plastering, sound insulation, and even as an artificial soil. The large volcanic eruptions that took place at Taupo somewhere about A.D. 200 caused large quantities of pumice, the natural lightweight material, to be carried downstream by the Waikato and Wanganui Rivers. Nearly 50,000 tons are quarried each year at Horotiu and Aramoho to be used in sandsoap, scouring powders, and insulating material, and nearly 1,000 tons are exported. Fine pumice, deposited along more ancient courses of the Waikato River, is worked principally as a filler at Takanini and Hunua near Auckland.

Sulphur occurs around many hot springs of the volcanic zone from Taupo to White Island, and 22,000 tons have been mined. Little now remains, nor are reserves of pyrite (iron sulphide) known to be high anywhere – the best known occurrences being 15–20 million tons of iron sulphide near Thames, averaging 7–8 per cent sulphur.

At Parengarenga Harbour, in northern Northland, brilliantly white dunes of pure quartz (silica) sand make an area of 4 sq. miles look like a permanent snow field. Over 50,000 tons from here, and 10,000 tons from Mt. Somers in Canterbury, are used each year, mainly for glass manufacture.

Two minerals have special uses because of the distinct forms of their crystals. Crystals of mica are flat, and can be parted into paper-thin sheets parallel to the flat surfaces. These sheets are used in electrical insulation, and for small unbreakable windows that have to withstand heat. Mica has been mined from pegmatites, i.e., granite rocks with unusually large crystals, at Charleston and in south Westland. Crystals of asbestos are thin and fibrous, and can be spun and woven like cotton to produce cloth and rope. The deposit at Takaka in Nelson contains only short fibres; 300 tons are used each year to make asbestos sheeting and “sidings” for building.

The large talc-magnesite deposits, also at Takaka, are exploited for the fertiliser industry. It has been shown to be technically feasible to separate both constituents: talc, which is the basis of talcum powder, and magnesite, which is the mineral form of magnesium carbonate. The related calcium-magnesium carbonate, dolomite, is available in large quantities in Ordovician rocks at Mt. Burnett, Collingwood.

Some 190,000 tons of phosphate rock were quarried from the Milburn-Clarendon deposits, Otago, in 1902–24 and 1943–4. Only a small amount of low-grade (10 per cent P2O5) rock remains there, or, as far as is known, anywhere else in New Zealand.

Many clays, of use other than for brickmaking, are quarried, and a high-quality clay used to make electrical insulators is actually mined underground at Kaka in Nelson. Fireclays, formed by the chemical leaching of rocks by acid waters beneath coal seams, are used to make the characteristically white firebricks at Huntly and Kamo. The even more intensely leached white “ball clays”, from Hyde and Idaburn in Otago, have been used for the manufacture of white earthenware, while pottery clays, formed by past hot spring alteration of the volcanic rock rhyolite, are quarried at Matauri Bay (Northland) and Mt. Somers (Canterbury). Clays that are capable of absorbing greases to an exceptional degree, and can therefore be used as decolorising and cleansing agents, are known as “fuller's earth”. They have been worked at Kamo (Northland) and are known at Gore, Southland. Bentonite, a clay which swells greatly in water to form a gelatinous mass with the consistency of grease, is known in a number of places near the east coasts of both islands. Good quality material can be obtained only with selective working. That from Porangahau is used as a drilling mud and in synthetic foundry sands.

Diatomite may appear claylike because of its fineness, but it is in reality an accumulation of myriads of external siliceous skeletons of the microscopic primitive plants called diatoms. This light powdery material is used as a source of silica, as an absorbent (e.g., of nitroglycerine), and as a filtering agent. It is worked in the Rotorua-Taupo volcanic zone and at Middlemarch, Otago.

Greenstone is found as boulders in the Taramakau and Arahura Rivers in northern Westland, in rivers draining west and south (e.g., the Dart) from the Olivine Range in southern Westland, and from Milford Sound. Its close relative, serpentine, is being used increasingly in New Zealand's fertilisers, particularly because serpentine superphosphate is free flowing, an important factor in aerial topdressing. A number of deposits in southern Northland near Te Kuiti, and east of Nelson, and at Mossburn in Southland, yielded over 160,000 tons in 1963, while a huge deposit is being opened up at the most northern point of the North Island – Kerr Point.

Salt, worth over £1 million, has been obtained by solar evaporation at Lake Grassmere, Marlborough, since 1952.

For the commercial production of oil to be possible, several geological requirements must be satisfied. There must be thick “source beds”, i.e., sedimentary rocks which originally contained organic material; a degree of alteration to those rocks, such that the organic material is changed to oil (and/or gas), yet not so great that the rocks became excessively hardened and the oil lost; a “reservoir bed”, in the pore spaces of which the oil may collect during an upward movement brought about by its relatively low density; an impermeable “cap rock” in a traplike shape such that the upward movement is halted; and, finally, an absence of fracturing that might allow the escape of the trapped oil. Geological investigations to find oil areas satisfying these conditions began as early as 1860, and many holes have been drilled from Northland to Southland. Most interest has centred around those areas where oil seeps have been discovered at the ground surface.

In 1911 a reward from the Government of £2,500 for the first 250,000 gallons of oil produced was awarded to the Taranaki Petroleum Co. which was drilling the Moturoa field at New Plymouth. Since then, a total of over 6 million gallons have been refined and sold locally, along with considerable quantities of gas. The modern use of geophysics has allowed reasonably accurate inferences to be made of the detailed structure of unseen rocks deeply buried beneath the ground surface, hence the recent successful drilling at Kapuni and Mangahewa in the same Taranaki region, by Shell B.P. and Todd Oil Services Ltd. A large gas field was discovered, with subsidiary but important oil in the form of a condensate, from a hole drilled to a depth of over 13,000 ft down to thick Eocene coal measures.

Many other areas have been prospected, but oil has been located outside Taranaki only at Kotuku near Greymouth, where a few thousand gallons have been recovered. The East Coast of both islands has so far proved to be too complicated geologically and/or too broken structurally to allow any oil that might have been present to be exploited.

Oil shale is reported from several localities such as Doubtless Bay and the East Coast of the North Island, but appears to have economic possibilities only at Orepuki, Southland, and Nevis, Otago. At the former, 14,000 tons of shale, worth £7,236, yielded a relatively high figure of 43 gallons for oil per ton when worked in 1899–1903. Its reserves, placed at only 7 million tons, make it a less attractive proposition for the future than the hypothetically richer areas at Nevis, where a total of 90 million to 2,000 million tons of shale are estimated to average 12·6 gal of oil and 146 lb of ammonium sulphate per ton.