Section II.
Previous Observers.

The first notice of the geology of any part of Otago was by the Hon. W. Mantell, who, in 1848, travelled from Kaiapoi, in Canterbury, to Dunedin, and the observations he then made were published in the Quarterly Journal of the Geological Society of London for 1850. The most important scientific result of this journey was the valuable collection of Moa bones made at Awamoa,^* and from the swamp, at Waikouaiti, where Mr. Percy Earl had obtained his collection some three or four years previously. But many interesting notes on the geology will also be found in this paper. Mr. Mantell mentions the schists at Awamoko, which is the first record or this class of rocks in New Zealand, as also the limestones of the Kakanui river and Ototara, and the volcanic ash at Kakanui mouth. He also notices the blue clay of Moeraki, or Onekakara, as well as the septaria found in it, and he described the cone in cone structure which surrounds many of them. He also points out the difference between the Moeraki septaria and the ferruginous concretions of Kartiki, and mentions the occurrence of coal at Shag (Matakea) Point. The fossils he sent to England were examined by Dr. Mantell, Professor Morris, and. Professor Rupert Jones, who referred the Ototara limestone, with doubt, to either the eocene or the cretaceous periods, while the Onekakara clay they considered to be pleistocene.

The next publication was a short paper in the Quarterly Journal of the Geological Society for 1855, by Dr. C. Forbes, of H.M.S. "Acheron," which ship had been engaged in surveying the West Coast sounds and Stewart Island. Dr. Forbes mentions that the mountains in the centre of the Province are composed of crystalline and metamorphic rocks, but that the former appear on the coast only in the extreme south and south-west. These rocks on the West Coast are described as "granitic rocks of various kinds—gneiss, mica-slate, hornblende rock, &c." The Bluff Hill, Stewart Island, and Ruapuke, are described as almost entirely composed of "blue-colored granitic rock containing hornblende in the place of mica." Dr. Forbes also mentions the "flesh-coloured granite" at Preservation Inlet, and was the first to describe the coal that occurs there and on Coal Island.

In January, 1862, Dr. W. Lauder Lindsay delivered a lecture in Dunedin, on "The place and power of Natural History in colonisation," in which he mentions the volcanic rocks of Dunedin, Saddle Hill, &e. He was the first to mention the evidence of former "glacier or ice action" in New Zealand, but he mistook decomposed lava streams near Dunedin for boulder clays. He considered the sandstones of Green Island and Caversham to be either tertiary or upper cretaceous. He was also the first to point out that the gold of Otago was derived from the mica-schists, which he compared to the rocks of the Grampians, in Scotland, and considered them to be of lower silurian age. He also noticed that the rocks between Tokomairiro and the Clutha, were different from the schists. He divided the auriferous drifts into two series, the older of which included the lignite beds, and he stated his conviction that "gold mining is destined to become one of the regular, permanent, industrial resources of Otago."

He was also the first to describe the true nature of the Otago lignites or brown coals, and mentions the coal fields of Saddle Hill, Green Island, Tokomiairiro, and Clutha, and the lignite deposits of Waitahuna and Weatherstone’s Flat.

In October, of the same year, he read a paper "on the geology of the gold fields of Otago" to the British Association, which however appears to have been a resume of his lecture.

Meanwhile, the Provincial Government determined, in 1861, upon having a geological survey made of the Province, and Dr. Hector arrived in Dunedin as Provincial Geologist, in April 1862, and he engaged as assistant geologists, Mr. Williams and Mr. Davis, and subsequently Mr. Hacket.

The first report, by Dr. Hector, was on the geology of the Manuherikia Valley, and was published in the Provincial Government Gazette, of September 3rd, 1862. In this report, he describes the schists of the interior, and confirms Dr. Lauder Lindsay’s opinion that they are the rocks from which the gold has been derived. He also points out the main anticlinal curve running in a N.W. by W. direction, and describes the interior basins, the contents of which he arranges under the heads of older and newer tertiaries.

"The older tertiaries," he says, "are the deposits which gradually filled up the depression as it passed through the successive stages of submergence, from an estuary-like arm of the sea to a deeply excavated submarine valley. They invariably consist at the base, where they rest on the schist, of strata which indicate the neighbourhood of dry land at the period of their formation, supporting a vigorous vegetation which has been preserved to us as brown page 14coal, associated with, finely assorted beds of clay and gravel, indicative of current action in shallow water. Elsewhere, in the Province, marine shells have been discovered along with these beds. Over this group have been deposited strata of sand and conglomerate, formed of materials derived from the schistoze rocks…. The period of the greatest depression of the land, which corresponds with the close of what I term the older tertiary epoch, was marked in some districts of the Province by volcanic eruptions, during which basaltic lava was poured forth from rents in the earth’s crust, and flowed over what were then the lowest levels of the sea bottom, but which have now, owing to the preserving influence of the hard tough basalt, become elevated to lofty positions.

"It was with the first display of volcanic activity, that the elevation of the land commenced, and although, as is always the case, this elevatory movement was accompanied by degradation of pre-existing strata, rather than by the formation of new deposits; yet under favourable circumstances, this very degradation gives rise to local deposits, which are those that I shall provisionally term the newer tertiaries.

"During this period the rock-bound basin, afterwards to be drained by the Taieri and Molyneux rivers, became converted into a system of lakes, connected by streams, which slowly excavated terraces, and deposited in a more perfectly assorted form the materials which compose the plateau…. As the main exit channels of the basin were deepened, the lakes were in time drained, and the materials again assorted by the erosion of the streams."

Dr. Hector’s next report was the narrative of his "geological expedition to the west coast of Otago," in the schooner "Matilda Hayes," which was published in the Provincial Government Gazette of the 5th November, 1863. This report, although chiefly confined to a narrative of the expedition, contains many interesting and valuable notes on the geology of the district. He describes the geology of Bluff Hill, but calls the rocks "dark-grey felstone," "syenitic and felspathic gneiss," and fine grained-granite." He describes the basalt and limestone, at the base of the Longwood range, and the limestone of the Waiau, and he identifies them with those of Oamaru and Caversham. He also makes several remarks on the rocks of the Takitimu mountains, and Mt. Hamilton, incorrectly however, identifying the conglomerates of the latter with those of the Horse range, and the rocks of Howell’s point with those of the Nuggets. Notes will also be found on the rocks of Port William and Paterson’s Inlet in Stewart Island, and of the following sounds on the west coast, which, owing to unfavourable weather, were the only ones that he was able to visit. Preservation Coal Island: Chalky Inlet, including Edwardson and Cunaris Sounds; Thompson Sound, Secretary Island, and Crooked Arm; Milford Sound, and Anita Bay and Martin’s Bay.

In the report there are also many suggestive notes, bearing on the surface geology of the country, most of which I shall subsequently quote, and in it Dr. Hector is the first to give good evidence of the former great extension of the glaciers in Otago.

In 1864, Dr. Hector, in his departmental report, gave a large amount of information about the coal fields of Otago. All of this, however, will be found reproduced in a more convenient form in one or more of his subsequent reports. In this year also, Dr. Hector produced a manuscript geological map of Otago and Southland, which was the first geological map ever attempted of the Province. The original map is in the Otago Museum, and a copy exists in the Colonial Museum at Wellington, but as it was never published, it will be only necessary for me to remark that it differs materially from the map that accompanies this report.^*

The same year saw also the publication of Prof. von Hochstetter’s Geology of New Zealand^†, which, although not containing any new information on the geology of Otago, is important to us as containing the first systematic attempt at drawing up a table of the New Zealand formations, based on an examination of the fossils.

This is as under:—

Post tertiary and recent formations.
Younger tertiary strata.^‡
Hawke’s Bay Series—Wanganui beds, &c.
Awatere—Waitaki, Moeraki,
Older tertiary strata. ^§
Waitemata beds.
Raglan and Aotea limestones, &c.
Coals of Drury, Waikato, and Motupipi.
Lower Cretaceous Group.
Walkato, South Head, and Kawhia.
Coal Fields of the West Coast of Nelson,
Jurassic group.
Waipara beds,
Amuri beds,
Shaws Bay series,

In 1865, Dr. Hector published in the Quarterly Journal of the Geological Society of London (p. 124, &c.), a short paper on the geology of Otago, in which are embodied the results of his two year survey of the Province. This valuable paper is up to the present time the only attempt at a sketch of the geology of Otago as a whole that has appeared. In it he gives an ideal section from the west to the east coast, and divides the rocks as follows:—

The To Anau series he considers to be lower mesozoic, and the Kaihiku series to be metamorphic rocks "of not very ancient date.’’ The carbonaceous series, he says, is either of tertiary or of upper mesozoie age. This is what he afterwards (1868) called the cretaceo-tertiary formation. The great difference between these two classifications is that Dr. Hector makes a great break in the sequence between the lower mesozoie and upper mesozoie or tertiary rocks, while Prof. von Hochstetter acknowledges no such break. The other errors in Dr. Hector’s classification arc that (1) the Moeraki series are placed below the Oamaru series, although Mr Mantell had previously assigned them their true position; (2) The "carbonaceous series" is made to include not only the cretaceous rocks of Shag Point, but also the Jurassic rocks of the Mataura and Waikawa, which in reality fill up the break in his classification. (3) The Te Anau series are placed above inst ad of below the Kaihiku series; and (4) the granite of the West Coast is included with the gneiss in a" gneissgranite" formation.

In the same year, Dr. W. L. Lindsay read a paper on the tertiary coals of New Zealand to the Royal Society of Edinburgh. In 1866 appeared the Jurors’ Reports and Awards of the New Zealand Exhibition held in Dunedin in 1865. This contains a list of minerals found in Otago, and a valuable report (Appendix A) by Dr. Hector and Mr W. Skey, analytical chemist to the Geological Survey of Otago, on the coals, building stone, and minerals of New Zealand, of which I have made great use in the section on Economic Geology in this report.

In the same year Dr. Hector, who had been appointed Director of the Geological Survey of New Zealand, and had removed to Wellington, published a report on the coal deposits of New Zealand, which, however, does not treat of the geological position or age of the coal deposits.

In 1868, a paper was read to the Philosophical Society of Wellington, by Mr. J. Buchanan, Draughtsman to the Geological Survey of New Zealand, "on the geology of the country between the Lower Clutha and Mataura Rivers." But this paper appears never to have been published: at any rate I have never seen it.

In the Colonial Museum Report for the same year. Dr. Hector makes some remarks on the coals from the Hokanui Hill and Morley Creek, in Southland, but he here again falls into the error of considering the coal of Gtapiri and Waikawa as belonging to the same formation as the coals of the West Coast, and he confounds the eocene coal of Merely Creek with the 30 foot seam of liguite of pleistocene age on the Mataura.

In 1869, Dr. Hector read a paper to the Wellington Philosophical Society "on the geology of the outlying Islands of New page 18Zealand," ^* in which he remarks on the rocks obtained by Mr. Pearson, from Stewart Island, that they consist of "granite, gneiss, mica slate, felstone slate, and other crystalline metamorphic rocks, associated with granite-porphyry, diorite, and syenite" [Ibid. p. 185]. In the same volume [1. c. p. 361] Dr. Hector also published, under the title, "on mining in New Zealand," an abstract of four lectures delivered by him in July and August, 1869, at the Colonial Museum. In this interesting paper he gives a summary of the geology of New Zealand, dividing the rocks into two large divisions, one including the palæozoic and lower mesozoic eras, which he considers "represents groups from the upper silurian to the triassic periods"; and the other including the upper mesozoic and tertiary eras," which, from "the occurrence," he says—"of secondary cephalopoda and saurian reptiles in the lower groups, render it probable that the strata range from Jurassic formations upwards." This break in the sequence is evidently intended to be between the "carbonaceous series" and the ‘‘Te Anau scries" of his former classification. He also mentions [p. 364] that his "gneiss-granite formation" of the West Coast extends to Stewart Island.

In the same volume Mr. C Traill has a paper "on the tertiary series of Oamaru and Moeraki," in which he correctly contends for the miocene age of the blue clay of Moeraki (Onekakara) as against the pleistocene or pliocene age assigned to it in Mr. Mantell’s paper.

During this year also, Dr. Hector, in his Progress Report of the Geological Survey of New Zealand, 1868-9, notices the Mataura district, Southland, Preservation Inlet, Longwood Range, and Southern gold fields in general. In this report he states that the coal bearing formation of the Hokanuis "corresponds in age with the coal measures of New South Wales," and again, that "this formation corresponds in age with the upper part of the carbonaceous series of Australia, and below it in regular sequence the Otapiri section shows an immense thickness of lower secondary strata.’’ So that he here, in opposition to his lecture on mining delivered the same year, takes the coal formation of the Mataura from his "carbonaceous formation," and places it with his lower mesozoic strata, upon which it lies in regular sequence. He also includes the Morely Creek coal with the coal-bearing beds of Shag Point, and those of the Buller and Grey River, with those of Nelson, Waikato, and Bay of Islands in his "cretaceo-tertiary" formation, which he says "in some respects must be considered as intermediate between the chalk and lower tertiary formations."

He also, in this report, states that in the Longwood Range there is "a repetition of the leading features of the Coromandel Peninsula, where the Thames diggings are situated."

In this year also Dr. Hector published (although it was not issued until 1871) a geological map of New Zealand, with sections, in which the rocks are thus divided.

This is the only Geological Map of New Zealand as yet published. In it the geology of Otago is altered in several particulars. The Morely Creek coal is placed in the upper tertiary formation instead of in the cretaceo-tertiary, and the cretaceo-tertiary formation is made to include not only the Shag Point and Preservation Inlet series, but also the Otapiri, Mataura, and Waikawa series, which he had the same year identified with the coal measures of New South Wales. Even the Shaw’s Bay series and Kaihiku series which up to this time Dr. Hector had regarded as upper palæozoic are now included in the cretaceo-tertiary formation. The general geology, however, of the Province, and the position of the lower palæozoic and crystalline rocks, is shewn with tolerable accuracy.

During this year three papers were read to the Otago Institute on the geology of the Province. The first was by L. O. Beal, Esq., page 20"On the deposition of the alluvial deposits on the Otago Gold Fields," in winch he discusses the origin of the terraces in the inland plains, and contends for an almost complete ice cap having extended not long ago over the whole of Otago from the inland lakes to Dunedin. The second was by Mr. P. Thomson, "On the sand hills or dunes in the neighbourhood of Dunedin;" and the third was by J. McKerrow, Esq., "On the physical geography of the lake districts of Otago," in which he adopts a glacier origin for our inland lakes.

Dr. Hector published in the same volume a report on the Clutha and Green Island Coal Fields, which is founded on his departmental report to the Provincial Government of Otago, in April, 1864.

In the same year Dr. Hector read a paper to the Wellington Philosophical Society on the fossil penguin (Palœendyptes antarelieus, Huxlev), from the West Coast of Nelson, and from Kakanui, in Otago. In this he gives a grouping of the strata to which he has "collectively applied the term cretaceo-tertiary, as no wellmarked break that is common to all the sections that can be inspected has been observed in their sequence; and moreover certain fossil forms are found in all the members of the series.’’^† In this he now includes as the tipper beds, greensands and limestones, characterised by Pecten hochstetteri, ‘‘which represent the Ototara series," and in this view Dr. Haast concurred in 1873.^‡ It is from these beds that the fossil penguin was obtained, and in 1870 and previously Dr. Hector had always considered them, with. Prof. Hochstetter, to be tertiary, even miocene. So that between 1869 and 1872, the omnivorous cretaceo-tertiary formation is made to include sometimes triassic, and sometimes miocene rocks.

In this year, also, Dr. Haast was seat to report on the Shag Point Coal Field, and the results of his examination will be found, partly in the Geological Survey Reports for 1871-2, and partly in those for 1872-3.

In 1874 a paper was read to the Otago Institute by J. T. Thomson, Esq., "On Glacial Action in Otago," in which he contended that Otago formerly possessed a climate like that of South Victoria Land at the present day, and that the whole island wag then enveloped in a sheet of moving ice, glaciers projecting out to sea in all our valleys. In the same year, I published in the Geological Magazine a table of the sedimentary rocks of New Zealand, which had been drawn up for the use of the geological class in the Otago University. This table I need not reproduce, as it is, with two exceptions, identical with the classification followed in this report. The exceptions are (1) that I now consider the Matai and Wairoa formations as one; and (2) that I have given Dr. Hector’s name of Kakanui series precedence to my name of Tuamarina formation, which latter, therefore, now sinks to the rank of a synonym.

It will thus be seen that the classification of the New Zealand rocks is in a very unsatisfactory state, which, it is hoped, this present report may in some degree help to clear up. But until the large collection of fossils which Dr. Hector has taken home with him are described by palæontologists in England, we cannot expect that many of these questions will be definitely settled.