The Pareora Formation.

In speaking of tlie Oamaru formation, I have already stated that I had included with it in the Geological Map attached to this Report, the next, br Pareora formation. The latter is generally found reposing on the edges of the former, or where the Oamaru formation occurs in basins, towards its centre. It generally owes its preservation to harder calcareous beds, often consisting almost entirely of fossil shells, which are interstratified with more sandy and incoherent strata.

Extent.

Starting from the north-east portion of the Province, we find a well-defined zone of the Pareora formation beginning five miles north of the Motanau, and thence following the coast to some miles south of the mouth of the Waipara, where the Canterbury plains begin. Other portions occur in the Blythe, Greta, and Waikari rivers, where they form conspicuous cliffs. After crossing a small saddle of palæozoic rocks at the head of the Waikari, we meet it again in the valley of the Omihi and Glenmark creeks, whence it follows the eastern foot of the ranges as far as the Okuku river, forming also outliers on both banks of the Ashley river, of which that called the Moeraki Downs on its southern banks is the most important. We also find it well-developed in the upper course of the Waipara, near Heathstock. Between the Waimakariri and Rangitata, at a few isolated spots inland, the Pareora formation is only represented by small outliers; but page 317south of the last-mentioned river it begins on the banks of the Kakahu to assume larger proportions, covering on the banks of the Opihi, Pareora, and Otaio, a large extent of country, and reposing generally unconformably on the Oamaru formation. Between the lower course of the Waihao and Waitaki the low hills bounding the Waitaki plains are also formed of Pareora beds of considerable thickness. The principal outliers of this formation are found in the Broken River basin, and near Lake Heron, where they occur nearly 3,000 feet above the sea-level. In Westland, from near the northern banks of the Grey to the Hokitika river, the same formation is also extensively developed, containing a great number of fossils, of which several have hitherto only been found in that area. These western beds form (Captain Hutton's Kanieri group, and are considered by him to belong to the lower portion of the Pareora formation.

Sequence and Character of Rocks, and Position of Strata.

The principal beds of this formation consist mostly of bluish or greenish argillaceous sands, with harder calcareous, mostly fossiliferous beds interstratified with them. One of the best and most extensive sections is situated on the left, or southern banks of the Waipara, where the strata which immediately repose upon the Mount Brown series consist mostly of arenaceous and argillaceous beds, clays, sometimes marly or loose marine sands. The clays often enclose concretions of sandy limestones, and also harder beds of the same rock, impregnated with lime and alternating many times with each other. In them we meet at the foot of that mountain, and often in a perfect state of preservation, with a great variety of fossils, as, for instance, Voluta pacifica, Natica solida, Struthiolaria (several species), Lutraria solida, Cytheriz Enysi, Dosinia (two species), Venericardia intermedia, Pectunculus laticostatus, Lima crassa, and many others. These beds are either of littoral origin or shallow water deposits. They are overlaid by beds of conglomerate, mostly formed of small river shingle, deposited in a shallow estuary, and consisting of the debris of the palæozoic ranges near the upper course of the Waipara; but the destruction of some of the older tertiary rocks has also furnished material for their formation. These beds are together of a thickness of about 300 feet. Some contain two species of oysters, of which one is Ostrea Nelsoniana, which sometimes forms page 318regular beds. There occur, also, some casts of gasteropoda, mostly filled in the interior with crystals of calcareous spar. The beds are capped by loose marine sands, sometimes very calcareous, full of fragments of shells, and of a light-yellowish or greenish colour. Here and there harder bands of calcareous sandstones stand out from them as protuberances. The same Ostrea, Pectunculus laticostatus, and Pecten secta occur in them. Between them beds of conglomerate are interstratified, and the interstices between the pebbles mostly filled up with calcareous spar. The beds along the banks of the Motanau river and of Motanau island consist of similar strata, also resting upon the Oamaru formation, apparently conformably. The lowest beds consist of bluish sandy clays, with rolled pieces of shells, sometimes forming regular layers; they are divided in numerous banks by beds of calcareous sandstone six inches to two feet thick, standing out as protuberances. Sometimes the latter is separated in lenticularshaped masses, lying side by side in the sands. The uppermost deposit consists of a thick layer of hard fossiliferous calcareous sandstone, sometimes forming cliffs along the sea coast for a considerable distance, and in which most of the shells appear only as casts. This bed dips near the mouth of the Motanau river 10 deg. to the south-east.

There is a great similarity in the rocks belonging to this formation, owing, without doubt, to the same physical conditions prevailing during their deposition. The occurrence of small beds of lignite in them is only an exception. The principal localities where such beds have been met with are situated in the Moeraki Downs, at the mouth of the Waipara, in the Broken River basin, and in White Rock creek, a source branch of the Pareora river. The strata belonging to this series lie either conformably upon the Oamaru formation, or, what is still more usual, unconformably upon it. In many localities, as, for instance, in the Pareora and Waihao rivers, the calcareous greensands have become greatly denuded before the Pareora beds were deposited above them, or which is more commonly the case, along them, when the former stood as islands in the tertiary sea. From the sections attached to this chapter the relations of the beds to each other can easily be made out, so that I need not enter here into a more minute description.

The Kanieri group at the West Coast resembles in many respects the Pareora beds on the East Coast. The lowest bed visible consists of bluish sandy marls, glauconitic at their base. In them calcareous page 319nodules are of frequent occurrence, containing generally fossil shells, or cetacean remains. Gradually they alter to ferruginous sands, with layers of fossiliferous sandstone having a calcareous matrix, interstratified with them. Upon them reposes a thick bedded conglomerate, apparently the highest bed in the series; occasionally rolled pieces of shells and cetacean bones are enclosed in it.

In the list of fossils found in this formation, I have indicated those which are only found in the Westland series, the beds of which generally dip so slightly that they sometimes appear in a horizontal position.

Pareora Formation.

The following fossils have been obtained in the beds belonging to this formation:—

Mammalia.—Cetacea: In the lower Waipara, several vertebræ; also, portions of lower jaw. In Westland, at Kanieri, and the Waimea, a number of bones.

Mollusca.—Class Pteropoda.

Fossils.	Authority.	Localities.
Dentalium Mantelli	Zittel	Waitaki, Waihao, Mt. Harris
Dentalium irregularis	Hutton	Kanieri
Dentalium lævis	Hutton	Kanieri
Dentalium solidum	Hutton	Pareora, White Rock River Waikari, Mount Harris
Dentalium giganteum	Sowerby	Waikari, Waitaki
Dentalium conicum	Hutton	Broken river

Class Gasteropoda.

Fossils.	Authority.	Localities.
Murex, sp.	—	Mount Harris, Pareora
Typhis hebetans	Hutton	Mount Harris
Turbinella brevirostris	Hutton	White Rock River
Fusue tegens	Hutton	White Rock River
Fusue plicatilis	Hutton	Pareora
Fusue dentatus	Hutton	Mount Harris
Fusue Australia	Hutton	Waitaki
Fusue dilatatus	Quoy	White Rock River
Fusue Crawfordi	Hutton	Mount Harris
Fusue colus (?)	Linn.	White Rock Riverpage 320
Neptunea mandarinus	Duclos	White Rock River
Neptunea nodosus, var. r	Quoy	White Rock River
Neptunea (Sipho) costatus	Hutton	White Rock River
Acus nitida	Hinds	White Rock River
Pleurotoma Buchanani	Hutton	White Rock River, Pareora
Pleurotoma Awamoensis	Hutton	Mount Harris, Pareora
Pleurotoma Wanganuensis	Hutton	White Rock River, Waikari
Drillia fusiformis	Hutton	Mount Harris, Pareora
Defranchia excavata	Hutton	White Rock River
Clavatula Haasti	Hutton	White Rock River, Mt. Harris, Pareora
Bela robusta	Hutton	White Rock River
Buccinum Robinsonii	Zittel	Kanieri
Buccinum inflatum	Hutton	Kanieri, White Rock River
Buccinum carinatum	Hutton	Broken River, Waikari
Triton minimus	Hutton	Pareora
Triton Spengleri	Chemnitz	Waitaki
Cominolla subnodosa	Hutton	White Rock River
Cominolla ordinatis	Hutton	White Rock River
Ancillaria Hebera	Hutton	Waitaki, Pareora, Waikari
Ancillaria sp. undetermined, probably Australis	–	White Rock River
Ancillaria pomahaka	Hutton	Kanieri
Voluta pacifica, var. r	Hutton	Mount Harris
Voluta pacifica, var. C.	Hutton	Broken River
Voluta corrugata	Hutton	Waikari, Kanieri
Voluta pseudorarispina	McCoy	Broken River
Voluta subplicata	Hutton	Mount Harris
Turbinella brevirostris	Hutton	White Rock River
Mitra apicalis	Hutton	Mount Harris, Waitaki
Mitra Enysii	Hutton	Broken River
Marginella albescens	Hutton	Broken River
Cassidaria sulcata	Hutton	Kanieri
Natica Zealandica	Quoy	White Rock River
Natica solida	Sowerby	Kanieri, Waipara Gorge, White Rock River
Natica ovata	Hutton	Common
Sigaretes subglobosus	Sowerby	Waitaki
Sigaretes carinatus	Hutton	White Rock River, Pareora
Scalaria Brownii	Zittel	White Rock River, Pareora
Eulima acciculata	Pease	White Rock River, Pareora
Conus ornatus	Hutton	Waitaki
Conus Trailli	Hutton	Waitaki, White Rock River
Struthiolaria cincta	Hutton	Common
Struthiolaria tuberculata	Hutton	Broken River, White Rock River
Struthiolaria scutaluta	Desh.	Waitaki
Cerithium rugatum	Hutton	White Rock River, Waikari, Pareora
Cerithium nodulosum	Hutton	Broken River
Turitella rosea	Quoy	Broken River, White Rock Riverpage 321
Turitella Haustator concava	Hutton	White Rock River, Waitaki Broken River
Turitella tricincta	Hutton	Waikari
Turitella tricincta var. B.	Hutton	Waitaki
Turitella bicincta	Hutton	Kanieri
Turitella gigantea	Hutton	Common
Calyptræa maculata	Quoy	Common
Trochita dilatata	Zittel	Waipara Gorge, White Rock River
Crypta costata	Desh.	Waipara Gorge, White Rock River
Crypta contorta	Quoy	Pareora, Broken River
Crypta incurva	Zittel	Waipara Gorge
Crypta profunda	Hutton	Common
Trochus granosus	Lamark	Kanieri
Turbo superbus	Zittel	Broken River
Turbo imperialis	Zittel	Broken River
Turbo Stolizkii	Zittel	Pareora
Cyclostrema helicoides	Hutton	White Rock River
Cladapoda monilifera	Hutton	Broken River
Gibbula, sp.	—	Pareora

Class Lamellibranchiata.

Panopæa Zelandica	Quoy	Kanieri
Panopæa Worthingtoni	Hutton	Mount Harris, Waitaki Point, Pareora
Saxicava arctica	Linn.	Tengawai, Waipara Gorge
Corbula dubia	Hutton	Motanau
Corbula sulcata	Hutton	Mount Harris
Mactra inflata	Hutton	Motanau, Waipara Gorge
Mactra scalpellum	Desh.	White Rock River
Lutraria solida	Hutton	Lower Waipara, Kanieri
Lutraria sulcata	Hutton	Motanau
Zenatia acinacis	Quoy	Tengawai
Psammobia lineolata	Gray	Motanau, White Rock River, Pareora
Psammobia sp.	—	Waitaki
Tellina sp.	—	Pareora
Chione vellicata	Hutton	Common
Chione Stuchburgi	Gray	Waitaki
Chione Yatii	Gray	Broken River
Cytheria Enysi	Hutton	Lower Waipara, Broken River, White Rock River
Callista elegans	Hutton	Kanieri
Dosinia subrosea	Gray	Common
Dosinia Grayi	Zittel	Motanau, Lower Waipara. Gorge
Dosinia magna	Hutton	Broken River
Tapes intermedia	Quoy	Motanau
Tapes curta	Hutton	Broken Riverpage 322
Cardium striatulum	Sowerby	Motanau
Cardium spathiosum	Hutton	Broken River, Mount Harris
Venericardia intermedia	Hutton	Waitaki, Lower Waipara Pareora
Lucina divaricata	Lamark	Pareora
Crassatella ampla	Zittel	Broken River
Crassatella attenuata	Hutton	Broken River
Crassatella Trailli	Hutton	Mount Harris, Pareora
Modiola albicosta	Lamark	Lower Gorge Waipara
Modiola sp.	—	Lower Gorge Waipara
Arca sp.	—	Broken River
Pinna sp.	—	Motauau
Trigonia pectinata (?)	—	Pareora
Cucullæa ponderosa var. B	Hutton	Waikari, Broken River, Pareora
Cucullæa Worthingtoni	Hutton	Waitaki
Cucullæa alta	Sowerby	Common
Pectunculus laticostatus	Quoy	Common
Pectunculus globosus	Hutton	Common
Limopsis insolita	Sowerby	Mount Harris
Limopsis Zealandica	Hutton	Waitaki, Tengawai
Solenella Australis	Zittel	Mount Harris
Leda semiteres	Hutton	Waihao
Pecten scandula	Hutton	Kanieri
Pecten secta	Hutton	Kanieri, Motanau
Pecten Hochstetteri	Zittel	Waitaki
Pecten accrementa	Hutton	Motanau
Lima crassa	Hutton	Lower Gorge Waipara, Pareora
Lima colorata	Hutton	Pareora
Placunanomia sp.	—	Waitaki, Rangitata
Ostrea Nelsoniana	Zittel	Motanau, Lower Waipara
Anomia trigonopsis	Hutton	White Rock River

Class Brachiopoda.

Rhynchonella squamosa	Hutton	Broken River
Rhynchonella nigricans	Sowerby	Waihao
Waldheimia lenticularis	Desh.	Waitaki

Annuloida.—Class Echinodermata.

Astropecten Sandersoni	Hutton	Waikari
Echinus sp.	—	White Rock River
Arachnoides Zealandiæ	Gray	Double Corner

Actinozoa.

Turbinolia sp.

—

Broken River

page 323

Igneous Rocks.

No igneous rocks have been found in this formation in the Provinces of Canterbury and Westland, so that the volcanic disturbances which we were able to trace in the formations previously described had already ceased in this part of New Zealand. However, Captain Hutton believes that both in the North and South, in Marlborough, and Otago, volcanic action was not dormant during the deposition of the Pareora formation. He refers the basaltic tufas between Lyndon and the Hanmer plains in Marlborough, and the basaltic rocks of Moeraki, to that period, both of which I consider, however, to be of greater age, and to belong to the Oamaru formation.

Age and Thickness.

The beds belonging to this formation contain a large number of species of which, according to Captain Hutton, who has carefully studied them, 37 per cent. are identical with living forms, and consequently they ought to be classed as upper miocene. Considering that we are not yet fully acquainted with the molluscan fauna of our seas, except with that of the Littoral Zone, it is very possible, that when dredging operations can be carried on on a large scale, many of the species we now believe to be extinct, will be found still living. Consequently the number of living species will be augmented. In such a case, the age of the Pareora formation would be lower pliocene.

Although in many localities the beds of which this formation is composed are only a few hundred feet thick, in others, as for instance, in the middle and lower Waipara and the Waihao, they have an aggregate thickness of as many thousand feet, arenaceous material in the form of sands having been deposited in great abundance along the coasts in a shallow sea.

The name Pareora formation was first applied by me to these beds, in 1864, when examining the Pareora river, where they are well developed, this designation being adopted by Dr. Hector and Captain Hutton. It includes tho Kanieri group (lower portion), of Captain Hutton, and the Awatere group (upper portion of von Hochstetter).