Transactions and Proceedings of the New Zealand Institute/Volume 9/Article 88

by Stephenson Percy Smith

Art. LXXXVIII.—Sketch of the Geology of the northern portion of the Hawke Bay. By S. Percy Smith.

Plates XXII., XXIII.

[Read before the Auckland Institute, 27th November, 1876.]

The following notes have reference to the country lying to the northwards of the town of Napier, extending along the coast of Hawke Bay to the Mahia Peninsula, and inland for a distance of from 15 to 25 miles, as is shown upon the accompanying map.

The geology of this part of the North Island is tolerably simple. It forms part of a large elongated basin occupied by rocks of the tertiary age, called by Dr. Hochstetter the "Hawke Bay series," but now I believe included in the Ahuriri formation of Captain Hutton,^[1] and includes also rocks of an older date, all of which have been deposited on the flanks of the slate mountains found a few miles further inland. The greater part of the eastern edge of this basin has been gradually eaten away and removed by the action of the sea, but in the northern part of the district the westerly dip of the beds shows that part of the ancient margin is here preserved. This may also be seen a little further south, near Cape Kidnappers, where the strata all dip towards and under the Ahuriri Plains. A line drawn from near Napier in a north-easterly direction to the falls at Te Reinga on the Wairoa Biver, will very nearly coincide with the synclinal axis of the basin, towards which the strata on either side regularly dip, Scinde Island being part of the youngest formation present.

I very much regret that owing to want of time I was unable to carry my sections a few miles further westwards, so as to show the relation between the rocks here described and the old slate rocks forming the axis of the island, and which extend uninterruptedly from Wellington to the East Cape, forming the Tararua, Ruahine, and Urewera mountains. To anyone accustomed to the shapes presented by mountains of this class of rock, however, there is no mistaking their appearance as seen even from a distance of several miles. Their positions therefore will be indicated on the accompanying sections with tolerable accuracy.

That an extensive series of stratified argillaceous and sandstone rocks exists between the lowest beds shown on Section No. 1, Plate XXIII., and the slate ranges at Huiarau is evident from the appearance of the country looking westward from the high mountains surrounding Lake Waikaremoana, where every here and there the white surface of the rock has been exposed on the hill sides by land slips.

The upper part of this formation is the lowest and oldest shown on the sections. It crops out on the shores of Lake Waikaremoana, forming low white cliffs, and partaking of the same dip as the superincumbent sandstones and gritstones. In its lithological characters it somewhat resembles the Papa Rocks, to be described further on, but is much harder and whiter, and contains in places peculiarly-shaped cement stones or septaria, which, owing to the weathering of the clay in which they are embedded, often stand out in grotesque forms.

I only saw fossils in one spot, and regret that I was unable to procure any of them.

Waikaremoana Sandstones.

Lying conformably on these clayey strata are a series of very hard sandstones and gritstones, having a probable thickness of over 2,000 feet. These sandstones form the Panikiri and Matakuhia ranges, most prominent features, rising in one long slope of 20° from the east, to a maximum height of 3,905 feet above the sea, and then suddenly descending on the western face 1,900 feet, nearly perpendicularly, to the shores of the Lake. The prevailing colour is greyish-white where exposed to the action of the weather, but when in the form of boulders, as seen in the river beds, it is a rich dark brown. The stratification is well marked, the beds dipping to the southeast at angle of 20°. The hardness and sharpness of these sandstones is such, that they will probably be used at some future date as grindstones and sharpening-stones, and also for the purpose of flagging, for which they are well adapted, as slabs may be obtained often of ten feet square and from six to eight inches in thickness.

They form most picturesque groups on the shores of the Lake, where broken by joints and fissures, which are generally filled with a rank growth of vegetation, conspicuous amongst which is the graceful Beech tree (Fagus), which in the higher parts of the mountains forms large open forests. In the month of February on these trees is often to be seen a very handsome Scarlet Mistletoe, which I have seen nowhere else.

The western line of outcrop of the sandstones may be traced for many miles to the north-east of Waikaremoana in a succession of bold precipitous bluffs facing the north-west.

The Lake itself lies at the foot of these mountains, and is about eleven miles long, with an average width of two miles, its greatest breadth being opposite the Constabulary Station of Onepoto, where it is four miles across. It is acknowledged by all who have seen it to be by far the most beautiful of all the Lakes of the North Island. The grandeur of the bluffs of the eastern side, rising as they do at Ohiringi 1,100 feet perpendicularly out of the water, is unsurpassed by anv cliff scenery I am acquainted with; whilst

the innumerable long narrow arms, charming little bays, and rocky islets of the southern and western shores, are equally beautiful in their way. The Aniwhaniwha Waterfall, at the north-east end of the Lake, is well worthy of a visit; a boat can be taken right up to the deep pool at its foot, and from there the double Fall can be seen to great advantage as it tumbles over the sandstone cliffs. The shores of the Lake are everywhere very steep, and, with a few exceptions, covered by forest right to the water's edge, the most common tree being the beautiful Beech.

The surplus waters are carried off by the Waikaritaheke River, though in ordinary weather the outlet is not visible, being subterraneous. On descending the dry watercourse of the river some little way, however, it is seen bursting forth from a crevice in the rock, and thence descends in a series of rapids to join the Wairoa, falling in the first three miles as much as 1,500 feet. There are several of these underground outlets, which are sufficient under ordinary circumstances; but after very heavy rains, or a westerly gale, the lake rises sufficiently to overflow the rocky bar at the mouth of the river, and then the water descends as a flood. The height of the lake above the sea is 2,015 feet, and that of Waikare-iti, a small lake situated a few miles to the north, is 3,122 feet, being probably the highest sheet of water in the island.

Lower Papa.

Resting on these Waikaremoana sandstones, the next formation, is a a great thickness of calcareous clayey marls, known universally on the East Coast by the name of "Papa Rock." This papa rock occupies probably the largest surface area of any rock met with between the East Cape and Napier. It is not, however, a continuous formation. I believe it to be of several different ages. At the line of junction between this and the underlying sandstone there is evidence of a break in the continuity of deposit, as may be seen in the valleys of the Waikaretaheke and Ruakituri, where the Papa contains embedded in it large boulders of the sandstones, showing that an elevation of the sandstone must have taken place sufficient to have formed a coast line upon which the denuding powers of the sea had been exercised in the formation of these boulders. The dip of the two formations is, however, very nearly the same. These beds are generally distinctly stratified, with here and there bands of a much harder and more sandy rock. At the point where the Waiau River first enters them, are to be seen embedded in the Papa large boulders of exceedingly hard yellowish cement stones or septaria. They are best seen under the Pukaramea Bluff, where the beds of the streams are often filled with them. Fossils are apparently scarce, though no doubt a proper search would reveal a great many more than I saw.

Maungaharuru Sandstones.

Lying on the lower Papa is found a vast series of hard standstone and gritstones, with thin strata of limestone composed of rolled fragments of shells and interbedded bands of Papa. This sandstone bears a great resemblance to that of Waikaremoana, being equally hard, and generally of the same colour, although it is sometimes varied by bluish and yellowish varieties, more especially in its upper parts, where it is also much softer. They extend from Maungaharuru to the Waiau river, where they are lost to view, having apparently suffered great denudation, and are covered by the next formation, until some 25 miles to the north-east they again occur at Te Reinga, the point where the Wairoa River precipitates itself over their outcrop in a magnificent fall. Continuing on to the east they compose the lower part of the Whakapunake range, attaining an altitude above the sea of 3,198 feet, and forming some grand perpendicular cliffs facing the east or seaward side of the basin. From here they tend to the south-east and south, finally reaching the sea coast near Nuhaka, where however the uppermost beds only are seen, composed of soft yellowish sandstone containing many fossils. At Nuhaka, the Papa is seen immediately to the east of these sandstones, but there is some doubt as to whether it belongs to that formation already described or to the middle Papa, which overlies the sandstones to the south-east. It contains some of the same cement stones. The question will ultimately depend upon the presence of the same fossils, but as I obtained none, either here or in the southern part of the lower Papa, the matter must at present remain an open question. The bands of limestone occurring with these sandstones are composed almost entirely of broken and rolled fragments of shells, principally of the genera Pecten, Ostrea, and Waldheimia. The dip of the beds varies from 17° to 29° 30′, being greatest on the slopes of Maungaharuru. Here the surface of the country is broken up into deep gorges with perpendicular sides of grey sandstone, the bottoms of which are occupied by streams, ponds, patches of bush, and numerous waterfalls, forming altogether a most picturesque country.

Pohue Papa.

We have now arrived, in our upward course, at a point where a considerable break appears in the sequence of the beds, which is plainly seen where the two formations meet. Section 2, Plate XXIII., exhibits the unconformatibility of the beds as see on the Upper Waikare stream, where the Papa, dipping at about 10°, abuts against the steep face of the sandstones, dipping under them at an angle of 29° 30′. This unconformability is a marked feature in viewing the country anywhere near the line of strike of the beds, where the older strata, even in places where the sandstone (as I suppose) has been

denuded off, are seen dipping at a considerable angle, forming hills which are quite characteristic and different in shape to the Papa hills of the overlying formation. I have termed these beds the "Middle Papa," to distinguish them from those of the same lithological characters both above and below them. They are composed of the same bluish marly clays, with intercalated seams of harder, more sandy Papa. Their general dip is about 10°, varying in direction from south-east, near Maungaharuru, to south and south-west as their northern termination is reached. Fossils are plentiful, but, as is usually the case when embedded in Papa, are of so fragile a nature that it is very difficult to preserve them. I obtained eighteen different species of Testacea from these beds in different parts. In this formation we first see signs of local disturbance, which is not continued, as far as I am aware, into the overlying one. We must therefore suppose that the movement took place before the deposition of the later ones, and was confined to a small area; this being very near the axis of the synclinal basin. As a general rule, the uniformity in amount and direction of the dip in each formation, over large areas, is very remarkable, and shows, I imagine, that the last elevation which brought the beds into their present position must have been on a large scale, and extending over a protracted period. It is probable that this Middle Papa thins out considerably towards the south, as is shown on the map. It is, however, I think, present at Pohue, a point on the Taupo road, although I did not actually see the rock itself, but a large Dentalium, which is a characteristic fossil of the beds, was brought to me there, and described to me as having been found in blue clay at the foot of the Titiokura Pass.

Brown Sandstone and Conglomerate.

Lying conformably on the Middle Papa is found a considerable thickness of brown soft sandstone, overlaid by beds of conglomerate formed of slaty pebbles cemented together by ferruginous matter. The best section of them is seen along the Taupo road from Rangimaipapa Hill to Te Pohue Lake. Both beds thin out and gradually disappear to the north. The conglomerate itself is very easily traced across country by the steep escarpments it presents, especially towards the west or uptilted side. I saw no fossils in either of these beds.

Esk or Upper Papa.

We next come to the Upper Papa, which there is every reason to believe is not conformable to the conglomerate underneath. Of this, however, I cannot be certain, as I had not time to search in positions which would show their line of junction. This Papa is wonderfully full of fossils, of which I brought away 21 different species, many other larger ones being much too fragile to get out of their matrix. The nature of this rock is much like the two formations of the same name already described, but there are certain differences in its characters by which it may generally be recognized in the field; and these are, first, the perpendicularity with which it stands up in cliffs, its greater homogeneity, and a peculiar form that the fracture of the rock takes as it weathers and falls, which is conchoidal, like the fracture of flint, only on an immensely larger scale. It seems also more liable to small slips. Standing on the Purohutangihia range, and looking northwards towards the Wairoa, these beds may be distinguished from the Middle Papa (on which they rest, beyond the limits of the brown sandstone) by the enormous number of land-slips which dot the surface of the country, giving it an appearance of great barrenness: this is far from being the case, however, for whenever the soil is derived from the Papa rock, it is very rich indeed.

The quantity of material which is yearly precipitated into the beds of the streams off the surface of these Papa hills in this district is something incredible, and will ever be a constant source of heavy expense in keeping the roads open. During the heavy and continued rain of last January, many of the roads were simply impassable by horses for weeks, and many millions of tons of clay must have fallen. Some of the slips were of large extent. I saw one myself which was three-quarters of a mile long and a a quarter of a mile wide, which had slid down the side of a mountain into a gully, carrying everything before it. Large trees were uprooted and left, many of them with their heads buried deep in the ground and their roots high in the air and large Rimu trees, six feet in diameter, were broken short off in a manner that would scarcely be believed, whilst enormous masses of rock as large as cottages were piled up pell-mell on the tops of the trees. Another slip is described by one of the Surveyors as over a mile long, which fell into the Waiau River, damming up its course and causing a long narrow lake to form, three miles long.

I have already spoken of the fertility of the Papa soil. This is proved by the readiness with which the grass takes on the surface of the newly-formed slips.

Brown Papa and Calcareous Sands.

Above this Upper Papa another bed of conglomerate is seen in the Esk Valley, but it is of no great extent; and above that again are a series of calcareous clays, which have a very small surface exposed horizontally, owing to the ease with which they disintegrate and are carried away by water. They are generally fossiliferous, and range upwards for about 500 feet and are then overlaid by a hard calcareous sandstone, also containing numerous fossils, the most common ones being species of Arachnoids and Placunanomia. It is this sandstone which forms the lowest strata seen at Scinde Island, Napier, where it occurs at the sea level, and is there overlaid by the Napier limestones, which have a thickness of about 300 feet.

Napier Limestone.

A little further to the north at Tangoio it is somewhat less, and is divided by strata of dark grey clays and softer yellowish limestone. Further inland it again increases in thickness, being probably 300 feet deep along the bluffs of Purotangihia range. These limestones and associated beds form to the north of Napier a high broken plateau, rising at Purohutangihia to 2,046 feet, and thence sloping gradually to the sea near Tangoio, where the cliffs are 250 feet high, but rising again towards the north at Matangimoe, where the cliffs are 1,200 feet in height above the sea. The limestone generally has steep escarpments bounding it, often quite inaccessible. It is full of fossils, generally rolled and worn, principally Pecten and Ostrea. In some places, however, the shells are perfect, as in a branch of the Mangapikopiko stream, where the bottom of the valley is strewn with large oyster shells in incredible quantities.

This limestone (if we except the much later formed deposits of shingle, pumice, and river terraces) is the youngest of the rocks in the district of which this paper treats. It has a very considerable extension to the south of Napier, reaching as far as the upper end of the Wairarapa Valley, and is probably of the same age as the limestones found on the southern flanks of the Kaimanawa Ranges on the other side of the Ruahine Mountains. That it has suffered very great denudation I have not the slightest doubt, as it gradually rose from the sea by the action of running streams, and I may add by the wind, which as a denuding agent is by no means to be despised, at all events in this part of the country. An inspection of the map (Pl. XXII.) will show that several out-lying patches are scattered over the district, extending inland to Maungaharuru, and northwards to Whakapunake and the Mahia Peninsula. All these isolated portions dip regularly towards the centre line of the Hawke Bay basin, and with one exception the fossils are the same, as far as my imperfect knowledge of the subject goes. This exception is the mass of limestone capping the hills to the east of the Wairoa River, and extending to Whakapunake. Here the rock is composed almost entirely of Waldheimia shells, giving it in places a peculiar botryoidal appearance. Whether the other fossils common to the rock in other places are present also, I am unable to say, but I saw none in the few places I was able to examine. The dip of the underlying strata is also hidden in this part, excepting on the bluffs of Whakapunake, where the limestone appears to rest on the Maungaharuru sandstones, but a little to the north of Te Hiwera, the Papa is seen dipping south-south-west, whilst the Waldheiniia beds dip nearly west. At Moumoukai, on the Nuhaka River, is another patch of limestone, containing the usual fossils, and dipping to the west at about 10°, whilst at Te Tuhi a few large blocks are left capping the hill, also with the same fossils. It will be seen from an inspection of Section 3, Plate XXIII., that if the limestone there shown were continued westwards with the same dip, that it would cut the Maungaharuru Range, both at its highest point, 4,265 feet above the sea, and also at Te Waka, in the positions where we actually find it capping the range. This shows, I think, that the introvening space was at one time occupied by continuous sheets of limestones, which would have rested unconformably on the lower strata of conglomerate, etc., and which have been denuded off; in the first place by the action of the sea as the country generally rose, and later by sub-ærial agencies.

I have mentioned above the occurrence of pumice in this district. It is found nearly everywhere: on the river terraces, the hill sides, and on top of the highest mountains, covering the surface with a deposit of sand more or less deep, and in larger or smaller particles. During the course of the last five years it has been my duty to visit the tops of most of the higher mountains lying between Napier and Tongariro, and thence northward to the country under consideration, and in every case a deposit of pumice sand has been found, sometimes plainly showing, at others covered by vegetation. On the Panikiri and neighbouring ranges around Waikaremoana, it is found of a considerable thickness, whilst the lower lands along the lake are covered by it sometimes to a depth of three feet. On the eastern side of the Maungaharuru Range it is very thickly deposited, being often, in the gullies, six to eight feet thick. The extensive terraces of the Lower Mohaka River (which contain as large a quantity of level land as is to be found in the district) are thickly covered with it, thereby rendering them unfit for cultivation.

Towards the east the deposit gradually thins out, until, approaching the vicinity of Poverty Bay, very little is seen. The only spots that are free from it are the lowest terraces of the rivers and the surface of the slips, and, as the country lying along the coast is the most subject to these slips as mentioned above, it is here that the pumice has in a great measure disappeared, thus allowing the grasses to spread.

The general opinion appears to be that this pumice was ejected from Tongariro and the adjacent volcanoes, and was spread over the surface of the country by the wind; and there are certain considerations which favour this view, such for instance as finding the greatest thickness of the sand on the lee sides of the high ranges, where it would naturally accumulate; and also from the fact that the size of the articles appears to diminish as we recede from the supposed centre of distribution; but at the same time this will not account for all the facts. An examination of the sand seems to show that all the particles are waterworn or abraded, and that many of them are too large to be carried by an ordinary wind, being sometimes as large as walnuts, though the average size would be about an eighth of an inch in diameter. The only other hypothesis which would account for the presence of pumice over such an extent of country is, that it has been carried into its present position by water. No doubt many of the extensive pumice drifts of the North Island do owe their origin to that cause, notably the pumice plains of Kaingaroa, near Taupo, which in places are regularly stratified, and often contain the trunks of trees, lying in a horizontal position, converted into charcoal; but there is a great deal of difference between the pumice deposits of Taupo, the Waikato, and the inland portion of Taranaki and those of Northern Hawke Bay. The former invariably occupy level plains or depressions, which no doubt were at one time lakes. To my mind, a deposit of a light substance like pumice, which ordinarily floats on the surface of the water, is only possible in enclosed sheets of water, which would not allow of its escape. If it once reached the open sea it would be carried far and wide by the winds and currents. There is one thing, however, which should not be forgotten, and that is, that the enclosed air, to which pumice owes its buoyancy, might under pressure be driven out, in which case, of course, it would become water-logged and sink, and would then form regular aqueous deposits like sand or clay. That such deposits are sometimes met with, I think every one must allow who has seen the Kaingaroa Plains, or the beds of coarse white sandstone found near the Miranda Redoubt, which is, I think, without doubt, formed of coarse pumice sand, consolidated under pressure; and the deep pumice strata found in the Tauranga District.

I observe in the last volume of the "Transactions of the New Zealand Institute," that Mr. J. C. Crawford, of Wellington, in his paper on "The Old Lake System of New Zealand," has touched upon this subject, and comes to the conclusion that the great central pumice drifts are lake deposits. In this I entirely concur, as far as relates to the country described by Mr. Crawford, but I think that the lake theory cannot be applied in this district. The large extent, and great height of the country over which the pumice is scattered precludes the idea that it is entirely due to the action of water, whilst the fact that the thickest deposit seems to be confined (in this district at least), to the northward of a line drawn in a true east direction from Ruapehu, would add force to the argument, that it was spread out by the prevailing westerly winds; and the water-worn appearance may be explicable on the supposition that it is due either to decomposition or to the attrition of the particles as they were ejected from the volcano. The amount of evidence, however, is not sufficient to come to a conclusion either way; nor are we justified in ascribing to Tongariro and its adjacent volcanoes the origin of the whole of this pumice, until a thorough exploration of the mountainous Urewera country shall have proved that it did not emanate from some nearer source. That volcanic rocks exist somewhere in that direction is proved by the finding of volcanic pebbles in the bed of the Wairoa River, which must have come down the Hangarou, one of its main branches, and which has its source somewhere in the neighbourhood of Maungapohatu, a lofty mountain some 20 miles to the north and east of Waikaremoana.

Of other recent formations present there are the river terraces, sand dunes, lagoons along the coast, caves in the limestone, and the fine gravel along the beach. The course of the Mohaka River presents some fine examples of the first. Near its mouth I have counted as many as eleven separate and distinct terraces, some high, some of only a few feet. These are all cut out of the solid Papa rock, and in the case of the higher one of all (which forms the true valley of the river) this has been spread over with a deposit of shingle derived from the slate mountains of the interior, of from six to eight feet thick. It forms a plain about ten miles long by a varying width of from one to two miles. It is covered thickly with before mentioned. Its general level is from 200 to 300 feet above the present river, which has cut for itself a deep precipitous channel, the sides of which afford an excellent section of the various beds through which it passes. The terraces of the Wairoa Eiver are not so well developed. There is one large one, however, which extends up both the main branches at a general height of from 50 to 150 feet above the river level. This is also generally covered with pumice, but not to so great an extent as those of Mohaka, whilst the recent and lower ones are nearly free from it. Of sand dunes there are not many, the coast being generally bold and precipitous. They are found at the low narrow neck of land connecting the Mahia Peninsula with the main (and which narrow neck, I may here observe, would, by a depression of 20 feet, again be submerged, thus making the Mahia an island), and also about the Whakeki Lagoon, which owes its origin to the banking up of the sand and gravel from the beach. A regular gradation may be observed in the sizes of the gravel on the beaches, which at Petane is small shingle, but sets smaller and smaller until at Nuhaka it has become ground down into coarse sand.

The caves of the limestone formation are numerous, but I never had time to visit them.

The Natives relate stories of most wonderful caves, grottos, and fissures as existing in the Whakapunake Mountain. They also stated that in one of these caves, the last of the Moas had his residence, and that their ancestors used to collect the feathers found near its entrance, as ornaments. My informant could not tell how long ago this occurred, and seemed rather inclined to set the whole story down as "he korero parau na nga tupuna" or old men's tales. It is, however, strange that I had heard, many years before, from a Northern Native, that the last Moa was seen on the East Coast, at a place called Whakapuna, evidently indicating this same mountain, though the last syllable of the name had been dropped.

There are several interesting physiographical questions, which a study of this district would illustrate, such as the origin of Lake Waikaremoana and other smaller lakes, most of which occupy true rock basins not scooped out by glaciers; the course taken by the present rivers, which are not always along the natural water-courses; the encroachment of the sea; and the alternations in the level of the land; but they would prolong this paper to an undue length, and moreover require to be dealt with by an abler observer than myself.

Appended hereto is a list of the fossils seen, as far as they can be identified, an estimate of the probable thickness of each group, and a map and sections.

---

List of Fossil Shells from Hawke Bay, deposited in the Auckland Museum.

	Upper.			Middle.			Lower.
	Limestone.	Calcareous Sands, &c.	Upper or Esk Papa.	Conglomerate.	Brown Sandstone.	Pohue or Middle Papa.	Maungaharuru Sandstone.	Lower or Waiau Papa.	Waikaremoana Sandstone.	Shale and Sandstone.
Dentalium, sp.	...	...	...	...	...	*	...	...	...	...
⁠{{{1}}}„⁠{{{1}}}„	...	...	*	...	...	...	...	...	...	...
⁠{{{1}}}„⁠{{{1}}}„	...	...	...	...	...	*	...	...	...	...
⁠{{{1}}}„⁠{{{1}}}„	...	...	...	...	...	*	...	...	...	...
⁠{{{1}}}„⁠{{{1}}}„	...	...	*	...	...	...	...	...	...	...
Murex zealandicus	...	*	*	...	...	...	...	...	...	...
Fusus, sp.	...	*	*	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„	...	*	*	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„ (large)	...	...	*	...	...	...	...	...	...	...	No Specimen.
⁠{{{1}}}„stangeri	*	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„plebius	...	...	*	...	...	...	...	...	...	...
⁠{{{1}}}„sp.	...	...	...	...	...	...	...	*	...	...	No Specimen.
Pleurotoma buchanani	...	*	*	...	...	...	...	...	...	...
⁠{{{1}}}„ sp., ind.	...	...	...	...	...	*	...	...	...	...
⁠{{{1}}}„{{{1}}}„	...	...	...	...	...	...	...	...	...	...
Turritella tricincta	...	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„ sp.	...	...	*	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„	...	...	*	...	...	...	...	*	...	...
⁠{{{1}}}„{{{1}}}„(prominent rib)	...	...	...	...	...	*	*	...	...	...
Crypta contorta?	*	...	...	...	...	...	...	...	...	...
⁠{{{1}}}„profunda?	*	...	...	...	...	...	...	...	...	...
Zizyphinus sp., indes	...	...	...	...	...	...	*	...	...	...
Purpura sp.	...	*	...	...	...	...	...	...	...	...	No Specimen.
Ancillaria, sp. (large)	...	*	*	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„(small)	...	*	*	...	...	...	...	...	...	...
Voluta pacifica?	...	...	*	...	...	...	...	...	...	...	No Specimen.
⁠{{{1}}}„sp.	...	...	...	...	...	...	*	...	...	...	No Specimen.
⁠{{{1}}}„{{{1}}}„(subplicata?)	...	*	*	...	...	...	...	...	...	...
Natica, sp. (vitrea?)	...	*	*	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„(callosa?)	...	...	...	...	...	*	...	...	...	...
Corbula zealandica?	...	...	*	...	...	...	...	...	...	...
Venus zealandia	...	*	*	...	...	...	?	?	...	...
⁠{{{1}}}„mesodesma	...	*	...	...	...	...	...	...	...	...
Dosinea anus?	...	...	...	...	...	*	...	...	...	...
⁠{{{1}}}„sp. (cyclina?)	*	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„{{{1}}}„	...	*	...	...	...	...	...	...	...	...
Venericardia australis	*	...	*	...	...	...	...	...	...	...
⁠{{{1}}}„zealandia	...	...	*	...	...	...	...	...	...	...
Mysia?	...	...	*	...	...	...	...	...	...	...
Mytilus, sp. (large)	*	*	*	...	...	?	...	...	...	...	No Specimen.
⁠{{{1}}}„{{{1}}}„(very small)	*	*	*	...	...	*	...	...	...	...
Pinna sp.	...	*	...	...	...	...	...	...	...	...	No Specimen.
Pectunculus globosus?	*	...	...	...	...	...	...	...	...	...
Solenella australis?	...	...	...	...	...	*	...	...	...	...
⁠{{{1}}}„cumingi?	...	...	...	...	...	*	...	...	...	...
Pecten triphooki	*	...	...	...	...	*	*	...	...	...
⁠{{{1}}}„williamsoni	...	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„zealandiæ	...	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„sp. (small)	...	*	*	...	...	...	...	...	...	...
⁠{{{1}}}„villicatus?	...	...	...	...	...	*	*	...	...	...
Placunanomia, sp.	...	*	...	...	...	*	...	...	...	...
⁠{{{1}}}„⁠{{{1}}}„	...	*	...	...	...	...	...	...	...	...
Ostrea, sp. (large)	*	...	...	...	...	...	?	...	...	...	No Specimen.
⁠{{{1}}}„{{{1}}}„(very small)	*	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„{{{1}}}„{{{1}}}„	...	*	*	...	...	...	...	...	...	...
Balanus, sp.	...	*	*	...	...	*	...	...	...	...
Lucina divaricata?	...	*	*	...	...	...	...	...	...	...
Mya? sp.	...	*	...	...	...	...	...	...	...	...
Leda? sp.	...	...	*	...	...	...	...	...	...	...
{{{1}}}„{{{1}}}„	...	...	...	...	...	*	...	...	...	...
Waldheimia trianguare?	*	*	...	...	...	*	*	...	...	...
Rhynchonella, sp. (like R. nigricans)	...	*	...	...	...	...	...	...	...	...
⁠{{{1}}}„sp., indes (small)	...	*	...	...	...	...	...	...	...	...
Terebratella gaulteri?	...	*	*	...	...	...	...	...	...	...
Fish Vertebræ	...	...	*	...	...	...	...	...	...	...
Arachnoides zealandiæ	*	*	...	...	...	...	...	...	...	...
Probable Thickness of each Group in Feet	300′	700′	1,000′	800′	1,200′	1,000′	6,000′	7,000′	2,000′
	$\scriptstyle {\underbrace {\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad } }$ 2,000′			$\scriptstyle {\underbrace {\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad } }$ 2,500′			$\scriptstyle {\underbrace {\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad } }$ 15,000′

1. See introduction to "Catalogue of Tertiary Mollusca," Wellington, 1873.