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The Pamphlet Collection of Sir Robert Stout: Volume 65

Waípara System

Waípara System.

In the South Island this system extends, with a few interruptions, from Cape Campbell in Cook's Straits to the river Ashburton in S. Canterbury (Amúri Scries), and an isolated patch occurs in the Trelissick basin on the upper Waimakariri. In Otágo it includes the coal-measures of Shag-point and the Horse Range (Matakéa Series), as also the coal of Mt. Hamilton and possibly a small patch on the north shore of Lake Wakatipu. In the Nelson Province it includes the coal-measures of Pákawau, and the bituminous coals of the Buller and Greymouth. In the North Island Mr. McKay has recognized the system on the east coast of Wellington , and it apparently covers a large extent of country in the Waiapu district, in which oil-springs are situated (Awanúi Series); and again on the Wairoa river north of Kaipara Harbour in Auckland. But

Reports of Geological Survey, 1878-9, p. 79.

Cox, Reports of Geological Survey, 1879-80, p. 22.

page 205 until the fossils from these North-Island localities have been carefully compared with those from the typical districts at Amúri and Waípara in the South Island, it is impossible to feel quite certain about their age.

The thickness of the system at Amúri Bluff is estimated by Mr. McKay at about 1600 feet. I considered the Matakéa Series at Shag Point to be between 6000 and 7000 feet. The strata are usually much disturbed except in North Canterbury. In Marlborough they go, in Benmore, to an altitude of 4360 feet. In Buller county they form mountains 5000 or 6000 feet high, and at Mt. Hamilton in Otágo they occur at an elevation of 3700 feet. In the North Island the greatest elevation of the system is in the East Cape district, and perhaps does not exceed 2000 feet.

This system is quite unconformable to the Hokanúi System in Marlborough and Canterbury. The coal-measures of the Malvern Hills and of Mt. Hamilton (fig. 3, f) rest on the Hokanúi System; those of Shag Point, the Grey, and the Buller, rest on the Maítai System; and those of Pákawau in Nelson on the Tákaka System, showing a complete stratigraphical unconformity. The palæontological break is probably equally great, but it has not yet been proved.

The upper part of the system in Marlborough and Canterbury consists of white argillaceous limestone (Amúri limestone) often containing flints. Dr. Hector calls it a deep-sea deposit; but it must have been formed within a few miles of land, and in the Kaikoura peninsula has thin bands of fine conglomerate running through it. Near Oxford, in Canterbury, a chalky limestone occurs which, according to Dr. Hector, is "made up chiefly of minute shells of Foraminifera" *, but I can find none in it. Although it is remarkably pure, it must have been formed close to land, as the Oxford Hills behind it rise to a considerable height. It is no doubt the remains of an old coral reef; but as no fossils have been found in it, it is uncertain whether it belongs here or to the Oamarú System.

In the typical district remains of marine Saurians belonging to the genera Plesiosaurus, Mauisaurus, Taniwhasaurus, Polycotyles, and Leiodon have been found and have been described by Sir R. Owen and by Dr. Hector . Among the Mollusca are Belemnites australis, Phillips §, Conchothyra parasitica, McCoy , a genus allied to Pugnellus, Conrad, of the North-American Cretaceous, Inoceramus, Trigonia sulcata, Hector, and many others not yet described. The plants found at the base of the system at Waípara are chiefly dicotyledonous angiosperms and Dammara. From Pákawau Dr. Hochstetter obtained Equisetites, Neuropteris, and either Zamites or Phœnicites; but leaves of dicotyledonous angio-

* Reports of Geological Survey, 1879-80, p. viii.

Brit. Assoc. Rep. 1861, p. 122, and Geol. Mag. 1870.

Trans. N. Z. Institute, vol. vi. p. 333.

§ Hector, Trans. N. Z. Inst. x. p. 487.

See Reports of Geological Survey, 1873-4, p. 37, footnote.

Trans. N. Z. Inst. vi. p. 358, footnote.

page 206 sperms also occur there*. The reptilian remains occur above the beds with dicotyledonous leaves at the Waípara, and they occur above the beds with Belemnites australis at Amúri Bluff: but the relation of the Belemnite beds to the leaf-beds has not yet been made out. Mr. A. McKay reports having found Ammonites at the Ten-mile Creek near Greymouth , and also near Waimirima, between Cape Kidnappers and Cape Turnagain on the east coast of Wellington . He also mentions finding a skeleton, apparently reptilian, at Lake Wakatipú, from which "fragments of a jaw with long slender Plesiosaurus-like teeth" were obtained §. In the Otágo Museum there is a fragment of an Ammonite from the Matakéa Series near Shag Point . Dr. Hector mentions Inoceramus and Belemnites from the Awanúi Series in the East Cape District; and Mr. Cox reports Inoceramus from the Wairóa river, Kaípara Harbour **. A "smooth Inoceramus" is also mentioned by Mr. McKay as occurring in many places between East Cape and Cape Palliser††.

No undoubted Mesozoic fossils have been reported from any other of the districts considered by the Geological Survey as "Crctaceotertiary." According to Dr. Hector "no trace of a Belemnite possessing the upper part of its guard or phragmocone has been discovered in any bed above the black grit"‡‡ that is about the middle of the Amúri Series. But, he says, smooth fusiform bodies, with a minute depression or perforation at the lower end, which exfoliate from the central portion of the guard of B. australis, have been found at Green Island, near Dunedin, at Waitaki, and at Mt. Hamilton in Otágo. He further says that these bodies form the Acanthocomax (? Actinocamax) of Miller, and have frequently been mistaken for spines of Cidaris. But as no whole guard of a Belemnite, even without the phragmocone, has as yet been found at any of these localities, nor in any rock supposed to be of the same age, the nature of this fossil must, for the present, be considered doubtful. The rocks in which it occurs at Green Island and at the Waítaki, I consider, from other palæontological evidence, to belong to the Oamarú System. This fossil is identical with the "pseudo-belemnite" described by Dr. Mantell from what are known as the "Hutchinson Quarry beds " at Oamarú§§, and which are considered by the Geological Survey to be of Upper Eocene age.

* Reports of Geological Survey, 1870-1, p. 157.

Rep. Geol. Surv. 1873-4, p. 81.

Rep. Geol. Surv. 1874-6, p. 45

§ Rep. Geol. Surv. 1879-80, p. 145.

Geology of Otago, p. 45.

Rep. Geol. Surv. 1873-1874, p. xviii.

** Rep. Geol. Surv. 1879-80, p. 22.

†† Rep. Geol. Surv. 1877-8, p. 22

‡‡ Trans. N. Z. Institute, vol. x. p. 489.

§§ Quart. Journ. Geol. Soc. vi. p. 329. The Ototara limestone of Mr. Mantell included the Hutchinson Quarry beds with abundant shells and corals, as well as the Oamaru building-stone.