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Geology of the Provinces of Canterbury and Westland, New Zealand : a report comprising the results of official explorations

(D) Glenmark

(D) Glenmark.

This chapter would be wanting in completeness, did I not offer a few notes on the now farfamed locality Glenmark, the property of my friend Mr Gr H Moore, to whose generosity Science is deeply indebted page 443for the invaluable collections of dinornithic remains, forming the pride and chief attraction of the Canterbury Museum. Glenmark is doubtless the spot which has furnished the largest quantity and variety of Moa-bones. These have been made available for the elucidation of the anatomy of these wonderful struthious birds, and a large number of Museums all over the World have received representative collections from the same source. Owing both to the fact that Moa-bones occur in beds of greater age close to these turbary deposits, and that their relative positions can easily be traced, Glenmark offers at the same time, a favourable spot to prove first, that there is no difference in the osteological characteristics of all the species and sub-species, whether they occur in the upper and lower beds, and secondly that all the different species, as it were, have appeared together, and have afterwards become extinct about the same time.

A small water-course, the Grlenmark Creek, flowing in a nearly north and south direction, joins the Omihi a few miles above its junction with the Waipara. The alluvial deposits of the Omihi having thrown a bar across the valley of the Glenmark Creek, here at one time a lagoon about half a mile in length was formed, which in course of time was filled up by turbary accumulations. It is in these deposits that the principal stores of dinornithic remains have been preserved. The valley has here an average breadth of a quarter of a mile, gradually widening till the termination of the broad outstanding ridge between the two valleys is reached. From here the Glenmark Creek flows across the alluvial deposits of the Omihi. Above the Glenmark station the valley by degrees contracts, and the water-course flows in a narrow channel either cut in limestone rocks or in post-pliocene alluvium, the latter about a mile above the home station being about 70ft thick. Here in several spots Moa-bones, generally in a fragmentary condition are not unfrequent, covered at least with 60ft of subangular river shingle. I collected here the remains of a number of species including D. maximus, elephantopus, and didiformis, together with a few bones of Aptornis and a fragmentary humerus of Harpagornis. The occurrence of such a variety of forms proves beyond a doubt that even during the Great Glacier period, all the species were already existing. The bones from this deposit are very heavy and impregnated with carbonate of lime.

A quarter of a mile lower down the creek, another section is exposed in a nearly vertical cliff, on the left bank. It consists in descending order of 16 feet of sands, often very ferruginous, repeatedly alternating with layers of river shingle, mostly of small size.

page 444
  • 2 feet layer of sandy peat, much compressed
  • 3 feet ferruginous sands, sometimes argillaceous
  • 3½ feet river shingle, with a ferruginous matrix
  • 4½ feet argillaceous sands
  • 4 feet river shingle, rather coarse

This lowest bed reposes on bluish micaceous sands, belonging to the Pareora formation, and dipping 14 degrees to the south by west. In the peaty layer the bones of a skeleton of Palapteryx crassus, were lying together. We were able to extract many of the principal ones but several of them were either broken, or had become flattened by the superincumbent weight of the strata. Descending the creek towards the Glenmark Station, and approaching the spot, where the turbary deposits have yielded the great harvest of Moa-bones, we find that the valley has enlarged to a breadth of nearly a quarter of a mile. Here the creek makes a sharp bend, flowing nearly at right angles to the direction of the valley, from the eastern to the western side, and exposes a fine section (No 8, on plate 9) exhibiting the following beds in descending order.

  • No. 1. 8 feet of Loess
  • No. 2. 4 feet of small river shingle consisting of palæozoic sandstone and old tertiary limestone
  • No. 3. 1 feet of sandy silt
  • No. 4. 6 feet of small river shingle, well stratified
  • No. 5. 1½ feet of peaty layer, containing a great number of Moa-bones
  • No. 6. 10 feet of river shingle cemented together by a ferruginous matrix

The lowest few feet cannot be observed as they are covered over by recent accumulations, and a talus from above. All these beds have a dip of about seven degrees, towards the centre of the valley, where the inward dip ceases, so that they appear to be horizontal. There is however a small inclination down the valley. Nos. 3, 4, and 5, are here of much broader dimensions, the peat bed No. 5 being nearly three feet thick. In the last mentioned layer, we obtained not only nearly every species of the Dinornithidæ, but also a few remains of Cnemiornis and Aptornis, together with a broken femur of Harpagornis. The bones are all very heavy and fossilized from calcareous matter filling the pores, consequently they are very different in character, from the bones occurring in the turbary deposit page 445lying on the top of the banks, about one hundred yards lower down the valley. This is the more important, because the bones in both beds belong all to the same species notwithstanding their great difference in age. Section No. 8, on plate 9, gives the details of the relations of these deposits to each other.

Close to the bend of Glenmark Creek, a small rill, now scarcely containing any water, comes down from the outrunning ridge here about 200 feet high, bounding the valley on the eastern side. It has a very short course, its source being on the summit not far off. This rill however, instead of falling into the creek, loses itself in the swampy ground on the top of the terrace, where doubtless a lagoon of considerable extent existed, before the turbary beds were formed. It is evident that a long lapse of time has been necessary to fill this pre-existing hollow with turbary deposits, and other material brought into the lagoon, and that during all that time the deposition of Moa-bones went on at intervals. I do not know if Moa-bones are found all over the bed of this former lagoon, many acres in extent, but as far as I have examined the deposits over an area of 500 feet in length, by 200 feet in breadth, they occur mostly in patches. The most important fact in connection with, the remarkable accumulation of dinornithic remains in this locality is their occurrence along the small rim of water previously alluded to, to the height of more than 20 feet above the surface of the turbary deposits, where it forms a broad swampy delta. "We dug here in several localities and found invariably in the lower portion of the peat, large stems of trees mostly white pine, so soft that the spade cat easily through the wood, together with Moa-bones, but although, the latter in not a single case were rolled, those of a complete or even nearly complete bird were never found lying together. It is thus clear that the bodies of the birds which perished here in crossing were only partly retained, partial decomposition having freed some of tne bones, which either were taken lower down the Creek, or found a resting place in the lagoon.

Where the small water-course enters the valley there was sometimes quite a network of timber, often of very large size, lying on the bottom. Covered by these trees or retained amongst them the dinornithic remains were of frequent occurrence. In some few cases the three principal leg bones with the pelvis and one or two dorsal vertebræ were found together in their natural position, the great mass consisted however of odd bones belonging to all known species, and to individuals of all sizes from the chick to the aged bird, brought there page 446by freshets from what may have been the crossing place a little higher up. This small creek in all its ramifications and with its deposits has been traced for a considerable distance during my excavations, and it has been found that the floor of the former lagoon was very uneven, so that even near the centre, the bottom clay beds rise sometimes to the surface. It is near these localities where the greatest harvest of Moa-bones was made, the carcasses or portions of birds having evidently been washed here against the banks and deposited in considerable quantities. I may here add that in that portion of the turbary deposits examined by me, the upper portion consists generally of from 4 to 7 feet of black peat, very pure and scarcely mixed with any other matter; below it 2 to 3 feet of more impure peat follow, reposing on a clay bottom. These lower peat beds have a somewhat reddish hue—principally when large quantities of Moa-bones are imbedded in them. They contain also large quantities of flax leaves, seeds, and stems of Raupo, and pieces of drift timber of various kinds. There are however other spots situated in several directions amongst the turbary deposits explored, where other causes have been in operation to form also considerable accumulations of dinornithic remains.

If we consider the nature of such a swamp as the Glenmark valley must have possessed at one time during the Moa age, there is all probability that it resembled closely some still at present in existence in New Zealand, where amongst the more solid ground already formed a great number of deep water holes are scattered over its surface. These deep stagnant pools, as ample experience has shown, are very dangerous to cattle and horses. When once a beast has fallen into them, there is no chance for it to escape from drowning. It is evident, looking at the physical features of the country, that the Moas had in this neighbourhood one or several crossing places to go from one side of the valley to the other, where a rich vegetation on the low ranges offered them doubtless ample food. Occasionally during this crossing one bird or another may have fallen into the water holes, and it would also not be too hazardous to assume that, when from some cause or other, a drove of Moas took fright, they have been driven or rushed across the same locality, where in their headlong course a great number of them may have perished in the same manner; the confirmation of such an hypothesis is furnished by the fact, that over the whole area under consideration are found what may be called regular nests of Moa-bones; bones of 20 to 30 page 447individuals of all sizes and ages are lying together closely packed in spots about five to six feet in diameter, whilst all around for some distance not a single bone is found. Moreover all the bones of the individuals perished in that particular spot, are found there together, and I was sometimes enabled to extricate with some care the greater portion of the same skeleton from the closely packed mass of the bones. These nests were consequently very different from the larger deposits, where to all appearance generally only portions of the carcasses had been drifted together.

It is impossible to give even approximately a number of the individuals, of which the skeletons have been preserved to us in these remarkable turbary deposits. Naturally, we obtained only a very small portion of the bones over that portion examined by me. A great number of them have of course decayed, others have been deposited at so great a depth that they were inaccessible, the turbary deposits being in many localities of such considerable thickness, that although a number of deep drains have been cut, we were not able to reach the lowest layer, usually containing the Moa-bones. However it is certain, that the number of specimens here imbedded must have reached a thousand, if not more. In Vol. I of the Transactions of the New Zealand Institute, I have published a list, giving the numbers of complete sets of leg bones, to all appearance having in each case belonged to the same individual, giving a total of 144 adults, and 27 young birds. This list included Mr. Moore's donations, and the results of my excavations up to the 15th February, 1868. However after that period, the largest excavations yielding most abundant material were undertaken, of which hitherto it has not been possible to draw up a full account. From that former list it appears that Meionornis casuarinus was the most numerous, forming more than a fourth, while M. didiformis represented more than a fifth of the total. They were followed by Palapteryx elephantopus, Euryapteryx gravis, P. crassus, and E. rheides. The smaller genera of Dinornis proper, such as gracilis, struthioides, together with maximus, robustus, follow next in number, D. ingens being represented only by a few individuals. Although unable at present to give even approximately the number of individuals obtained in the later and more extensive excavations, the proportions of the different species to each other agree in a general way with the published list.

We obtained of smaller species, during the former and more recent excavations, remains of five to six specimens of Aptornis, a few bones of Cnemiornis and of Anas Finschii, and portions of a skeleton of page 448Harpagornis assimilis. Of species still living in New Zealand, Apteryx australis and Oweni and Nestor, were represented by several individuals, together with a few bones of several of our aquatic birds, and a lower jaw of Sphenodon punctatum.

Opposite to these large turbary deposits on the right bank of Glenmark Creek a small water-course joins the latter, the banks of which for some hundred yards above its junction consist also of similar turbary beds, in the average 50 feet wide. In draining this creek it was found that these beds were of a depth of 8 to 12 feet, their lower portion being largely mixed with drift timber, and containing also a very considerable number of Moa-bones. The excavations in this locality gave also splendid results, and the same proportions as to the frequency of the different genera and species observed on the other side obtained also here. However the most remarkable discovery made consisted of the bones of Harpagornis Moorii, so named in honour of Mr G. H. Moore, the owner of Glenmark, proving that contemporaneous with the Moa a huge bird of prey existed closely allied to Circus and doubtless acting as scavenger, if not feeding on the young and enfeebled old birds.

Professor Owen in his XXI Memoir on Dinornis quotes Professor Cocchi's opinion that Dinornis crassus, elephantopus, giganteus (var. robustus) and Dinornis ingens belong to the neolithic or recent period, while at the same time that illustrious English comparative anatomist thinks, "that certain remains from the fluviatile deposits in the North Island representing the species Dinornis giganteus, ingens, struthioides, and didiformis, of a heavier and less recent character than the bones from the South Island, have come from birds which lived in postpliocene, quaternary, or even earlier times."

The turbary deposits of the South Island being so very rich in Moa-bones, it has been found far easier, and more expedient to send to England large collections made amongst them, than from the glacier or older fluviatile deposits. The bones found in the latter two deposits in this island are in the same if not sometimes more fossil condition, than those from the Northern Island, collected in similar beds. I have examined a whole series of Moa-bones from the Northern Island, obtained from sand-hills, kitchen middens and turbary deposits. They are quite similar in preservation to those collected in this Island from beds of the same character. The Glenmark sections, better than any other with which I am acquainted, show clearly that all the species of our Dinornithidæ have page break
Skeleton of Aptornis otidiformis Owen in the Canterbury Museum.

Skeleton of Aptornis otidiformis Owen in the Canterbury Museum.

page 449been living simultaneously, first appearing in the Great Glacier period and reaching to quaternary times, when they became extinct by the hand of man, and through other physical causes previously alluded to. Consequently the conclusions of Professors Cocchi and Owen, quoted above, cannot be sustained, when we take the occurrence of Moa-bones in the series of beds now examined over both Islands into account.

It has repeatedly been advanced as a proof of the recent extinction of the different Dinornis species, that the bones of the Notornis have been found in a few localities, together with those of the former, while afterwards that gigantic rail was discovered to be still living in some lonely parts near the west coast of this Island. A similar argument might be adduced to prove the recent extinction of the Mammoth, and the Woolly Rhinoceros in Europe, because the fox, the wolf, the hare, and a number of other animals, still living in the same part of the world were contemporaneous with those extinct gigantic mammals. I wish, however, to point to the striking fact, that in none of the localities examined by me, yielding such a rich harvest of Moa-bones, any remains of Notornis have ever been discovered. We must therefore conclude, that this bird was either extremely rare in the regions referred to, or that it then existed only in the more mountainous regions of these Islands. However, nothing was known of the exact habitat of the Takahe, (Notornis) till Sir George Grey—to whom I owe this valuable communication—obtained the information from some aged Maoris in the extreme South of this Island, that this rail is still now living on the mountains of the neighbourhood above the forest region, where numerous lagoons are dotted over the glacialized surface of the ranges. I now believe that the remarkable tracks I observed in similar mountain regions near the head-waters of the Rakaia were also those of this bird. At the same time it is possible, that the large bird of prey met with in the heart of the Alps, and to which I alluded on pages 37 and 135 may be the Movie or Hokioe of the Maoris, or even the Harpagornis of which the bones were first obtained in the turbary deposits of Glenmark.