The Pamphlet Collection of Sir Robert Stout: Volume 65
Waípara System
Waípara System.
‖ Reports of Geological Survey, 1878-9, p. 79.
¶ Cox, Reports of Geological Survey, 1879-80, p. 22.
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.
* 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.
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.