1.—Geology and Distribution.

The geology of New Zealand is both interesting and complex, and although the Director of the Geological Survey (Sir Jas, Hector, F.R.S.) has, with the small stuff at his disposal, done wonders, it cannot be expected that in an exceedingly rough country like the one under discussion, anything like the detail of the British maps should have been attained. As the age of the coal-beds has, at various times, been disputed, it will perhaps be better to give the Director's own words on this important question:—

"The Lower Greensand and Cretaceo-Tertiary Formations (Cretaceous System of Rocks).—The true and almost only coal-bearing formations of New Zealand. It is no doubt true that there are valuable deposit of fossil fuel occurring in various parts of the colony that have been variously referred to different geological periods during the past history of the Geological Survey, and the age of which is not yet satisfactorily determined. Some of these are now known to be of younger date than the Cretaceo-Tertiary period, viz., various deposits of lignite in the Wellington district of Nonh Island, and possible occurrences of the same material in the Nelson and Westland district of the West Coast of the South Island; also a deposit of the same nature found at Castlehill station in the Trelissick basin, Canterbury, and a bed of lignite overlying the marine beds of Miocene age within the watershed of the Upper Parcorn, South Canterbury.

More doubtfully to the same period must be referred the lignites or inferior brown coals of the Hakateramea and Waitaki valleys 45 to 50 miles inland from Oamaru.

There are also the thick deposits of fossil fuel occupying or found within the interior lake-basins of Central Otago, which have been generally referred to the Tertiary, sometimes to the late Tertiary, period; but the evidence is by no means clear that all the known occurrences of such should be ao referred. Again there are, farther to the south, in the Taicri, Cluthan, and Mataura valleys various and sometimes very thick deposits, in some place a mere lignite, in others a second or third-rate brown coal, which are usually considered as belonging to the Miocene period, but whicht in more than one instance, will in the future have to be placed in the Gretaceo-Tertiary formation. There is even now no decisive evidence that the Mataura lignite near the railway-line opposite the township of that name is not of Cretaceo-Tertiary date, and it is certain, from the abundance of ambrite (derived from a confferous tree closely allied to the Kauri of the North Island, but which has long since disappeared from the South Island) occurring in the deposit, that the vegetable matter composing it differed but little from that whieh formed the coal-seams of Green Island and Shag Point. The same remarks will apply, and with even page 65 greater force, to the country north-west of mataura, and flanking the Hokonui hills within, the watershed of tho Makarewa stream.

Exceedingly modern-looking deposits of lignite are found along the eastern shore of New Harbour, between Invercargill and the Bluff, but the very modern date which has been assigned to these deposits rests on no further authority than the but slightly compressed condition (comparatively speaking) and inferior quality of the lignite.

The brown-coal formation farther to the north-west at the Nighteaps, Morley Creek, and Centre Hill, there can scarcely be any question, belongs to the Cretaceo-Tertiary period; but there are farther deposits more to the west, and on the coastline towards Riverton and Orepuki, respecting the age of which there may justly be a difference of opinion, as the geology of this district has been worked out in the light of recent discoveries.

But, besides in these localities named, it has been contended that the North Island coals wholly, and those of Nelson and the west coast of the South Island In part (excepting the bituminous coals), together with all the coals of the east coast, saving those found in the Malvern Hills (Canterbury), at Shag Point (Otago), and at Mount Hamilton (in the Southland district), should all be referred, not to the Secondary epoch, nor to a Cretaceo-Tertiary formation, but to some part of the Tertiary period.

Practically, it matters not whether we consider our coal-fields to be Tertiary or Cretaceous, as regards the period when the coal-seams were deposited; but it is of the very greatest importance whether they belong to one or two or more periods, and it is this that, under guise of a controversy as to the age and nomenclature of the beds, is the point at issue, and it is to prove the identity of the principal coal-formations of the colony that the Geological Survey has laboured during the past fifteen years. Indeed, so far as my own views on the subject are concerned, they hove ever been what they are now—that we must regard all the great coal-deposits of New Zealand as belonging to one sequence of strata, or otherwise involve any systematic consideration of thorn in inextricable difficulty."^*

For convenience of classification and reference, the coals of New Zealand Lave been divided by Sir Jas. Hector as follows:—

I.

—Hydrous (coal containing 10 to 20 per cent, of permanent water). (a) Lignite.—Shows distinct woody structure, laminated, or shows that structure on desiccation; very absorbent of water. (b) Brown Coal.—Rarely shows vegetable structure. Fracture irregnlar, conchoidal, with incipient lamination; colour, dark brown; lustre, feeble; crocks readily on exposure to the atmosphere, losing 5 to 10 per cent. of water, which is not re-absorbed; burns slowly; contains resin in large masses. (c) Pitch Goal.—Structure compact; fracture smooth, conchoidal, jointed in large angular pieces; colour, brown or black; lustre, waxy; does not desiccate on exposure, nor is it absorbent of water; burns freely, and contains resin disseminated throughout its mass. page 66

II.

—Anhydrous (coal containing less than 6 per cent, of water). (a) Glance Coal.—Non-caking, massive, compact or friable; fracture cuboidal, splintery; lustre, glistening or metallic; structure obviously laminated; colour, black; does not form a caking coke, hut slightly adheres. This variety is chiefly brown coal altered by igneous rocks, and presents every intermediate stage from brown coal to anthracite. (b) Semi-bituminous Coal.—Compact, with laminæ of bright and dull coal alternately; fracture, irregular; lustre, moderate; cakes moderately or is non-caking. (c) Bituminous Coal.—Much jointed, homogeneous, tender and friable; lustre, pitch-like, glistening, often iridescent, colour, black, with a purple hue; powder, brownish; cakes strongly, the best varieties forming a vitreous coke, with brilliant metallic lustre.

Although it is only the anhydrous coals which are of value for purposes of export, the pitch and brown coals, and even the lignites are, for local purposes, when their greater bulk is not an insuperable obstacle, very important factors in the prosperity of a district.

Bituminous coal is found almost exclusively on the west coast of the South Island, at the base of a great marine formation underlying limestone, clay, and sandstone. The whole series has a thickness of several thousand feet, and contains, wherever it is found in contact with the older rocks, which are much metamorphosed and of indeterminate age, valuable seams of coal. As in other parts of the world, the quality of the New Zealand seams appears to vary very much, according to the amount of disturbance and dislocation that they have suffered since their deposition. Thus the lignites and inferior brown coals are comparatively free from faults; the pitch coals and glance coals have been mora disturbed, and the true coals have been in some cases subjected to great changes and dislocation.

Lignites occur in many places, principally in the South Island, where they arc found occupying the ancient rock-basins. They contain large fragments of wood, sometimes almost indistinguishable from recent specimens, and although they burn slowly, and with a somewhat unpleasant odour, are of the greatest possible local value in the interior, where the great height above the sea renders the climate exceedingly rigorous, and timber exists either sparingly, or not at all. Deposits are also found in the Lower Waikato basin and near Raglan, both in Auckland Province, and in Wellington and North Canterbury.

Brown coal is widely distributed, and is found on the Waikato river in the province of Auckland, at Kaitangata in Otago, and also in Southland, as well as in considerable profusion in Canterbury.

Pitch coal, which is a really excellent fuel for local use, has been found at West Wanganui and Reefton in Nelson Province, at Shag Point in Otago, on the Waikato river, and at Wangarou iti Auckland, and also in Southland.

It will be hardly practicable to consider in detail the deposits of the colony in any other than their geographical order, commencing at the north.