Art.XXXVI.—Notes on a Small Collection of Fossils from Wharekuri, on the Waitaki River, North Otago.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 36, 1903, Page 465

Art.XXXVI.—Notes on a Small Collection of Fossils from Wharekuri, on the Waitaki River, North Otago. By A. Hamilton. [Read before the Otago Institute, 13th October, 1903.] Plates XXXVII. and XXXVIII. Last Easter I had an opportunity of visiting a portion of the valley of the Waitaki immediately to the north of Kurow, in company with Professor Park, and we spent one day at Wharekuri, as I was anxious to see the locality in which Mr. McKay discovered a large series of remains of the huge whale with the seal-like teeth,ast;Rep. Geol Surv. N.Z., 1881, p. 73. called by Sir James Hector Kekenodon onomata.† Trans. N.Z. Inst., xiii., p. 436. A full description of the small deposit of calcareous greensands and of the great variety of fossils found is given on pages 67 and 68 of the Geological Report of 1881, and it will be seen from the notes that the locality is a very important one for collectors. Crossing the Wharekuri Creek at the bridge, we put up our horse and trap at the small accommodation-house close by and walked up the creek to a small coal-mine worked in a small seam of coal, and a short distance further on the schistose beds of the older rocks forming Mount Mary come in. On returning down the bed of the creek, about 12 chains before reaching the bridge on the main road there is a very interesting series of small faults, the main fault being nearly vertical and running N.N.W. by S.S.E. The beds here exposed on the cliffs on the east bank of the stream are about 40 ft. thick, 30 ft. of which are blue clayey sandstones very full of fossils, all squeezed and distorted; and on the down Fig. 1. Section 12 Chains above Bridge over Main Road, Wharekuri. a. Recent river gravels. b. Blue clayey sandstones (fossiliferous). c. Soft yellowish sandstone (not fossiliferous). f. Fault, about 2 ft. wide.

throw side of the fault about 30 ft. of soft yellowish sandstone, not fossiliferous. These are capped by several feet of recent river-gravels. The fault is 2 ft. wide. (See fig. 1.) The terrace gravels and silts form the high banks of the creek down to the junction with the Waitaki, which is here a fine river, carrying a large body of water and subject to high floods, just at the junction of the creek the river makes a sharp turn northwards across the valley, and has swept away the overlying river-gravels from a projecting point of dark-green clayey sandstone, leaving the surface perfectly bare, and over the whole surface are small concretions of hardened sand enclosing a great variety of fossils. As far as I can make out from Mr. McKay's report,* Rep. Geol. Surv. N.Z., 1882, p. 68. the remarkable series of bones of Section across Waitaki River Quarter - mile below Junction of Wharekuri Stream. A. Where the Aturia was found. a. Terrace gravels and silts, with moa-bones. b. Dark-green clayey sandstones, very fossiliferous. five specimens of Kekenodon onomata must have been obtained from the upper beds of this point before its recent erosion by the river. We were not able to find any bones or teeth of Kekenodon, but we were successful in collecting the fine specimen of Aturia figured on Plates XXXVII. and XXXVIII. The difficulty of getting this huge shell out of the hard marly greensand was very great, as a large trench had to be dug on all sides. Fortunately, sufficient of the matrix came away with it to hold the shell together until it reached the Museum, when Mr. Jennings, the skilful taxidermist, worked it out and cut it into two halves. The shell still retains the nacreous appearance. A portion of the thin outer chamber was unavoidably broken in the excavation, but the greatest diameter is still between 15 in. and 16 in. Amongst other fossils was a very fine Pleurotomaria 5 in. in diameter at the base, at present undescribed, and a considerable number of a Pecten allied to P. hutchinsoni, but having one side slightly ribbed and the other smooth, like P. Yahlensis of the Australian Tertiaries. Mr. McKay mentioned that, a large number of the concretions that he collected contained crabs. We only found one, but this is,

fortunately, well preserved, and bears a resemblance to the Harpactocarcinus figured by H. Woodward in the Quarterly Journal of the Geological Society (xxii., 51), but in is not that genus. Crassatella australis was plentiful, Trochus chathamensis, and a number of corals A few fragments of leaves were found, and the vertebra of a fish having a centrum 1 in. in diameter. Section across Waitaki River Three - quarters of a Mile below the Junction of the Wharekuri Creek. a. Recent river gravels. b. Terrace gravels and silts, with moa- bones. c. Sandy shell beds full of fossils. d Dark-green sandy beds. Following down the bed of the river, the section exposed for a mile or two is a cliff of about, 20 ft. of fine sandy material full of the most delicate and beautiful specimens of fossils— huge specimens of Dentalium giganteum, brachiopods of several species,Natica, Turritella, Limopsis, Lima, and a number of small species. A very fine collection could be made here by careful search., The conditions under which the beds were deposited seem to have been very favourable to the development of all forms of animal life in land-locked shallow seas with a mild climate. Explanation of Plates XXXVII and XXXVIII. Plate xxxvii. Aturia ziczac. Plate xxviii. Section of Aturia ziczac.