Chapter II. Orographical Features.

Beginning our examination at the northern boundary of the Province, we observe, as already pointed out, that the Teramakau, the western river near that boundary, here advances far east of the geological axis of the chain. This river has its sources near a saddle— the so-called Harper's or Hurunui Pass, 3150 feet high. From here a chain of an average altitude of 7000 feet has a west-south-west direction till it joins Mount Rolleston, where the geological main axis of the chain is reached. This range is generally wooded on both its lower slopes, very luxuriantly on the Teramakau side; whilst on the southern or Waimakariri side, only open beech forest grows. The range close to the Hurunui Pass, divided by a deep saddle, is formed of Snowcap Peak and Mount McCrae; wild rocky ranges, where several branches of the Teramakau, Hurunui, and Wamiakariri take their rise. Mount McCrae is separated from Mount Franklin by Walker's Pass-according to Mr. E. Dobson, 3619 feet high-leading from the Hawdon river (Waimakariri) into the Otihaki river (Teramakau). It is described as difficult of access, and with very precipitous slopes. Between Mount Franklin and Mount Williams, the next peak to the west, we find a similar Pass, named Goats' Pass page 179by the late George Dobson, who first explored it. He describes it, although scarcely higher than Arthur's Pass, as being far more difficult of access. To reach it, the eastern branch of the Bealey has to be followed. On its northern slopes the eastern branch of the Otira takes its rise. The next peak, Mount Williams, reaches already above the line of perpetual snow. It is separated from Mount Rolleston by Arthur's Pass, 3013 feet above the sea level, over which the West Coast Road has been laid out. These two last-mentioned mountains, without doubt, belong already to the central chain proper, being separated from their north-eastern continuation, Mount Wüllers-dorf, by theTeramakau. Mount Rolleston, about 8500 feet high, exhibits a truly alpine character, possessing considerable nevé fields, which, however, on the eastern slopes, do not form any true glaciers; towards the Crow river however, one of the upper branches of the Waimakariri, it sends down a glacier of the first order, the terminal face of which nearly reaches to the forest line, or to about 4500 feet. This is the most easterly glacier of the Waimakariri system. Mount Rolleston is connected by a high serrated ridge with Mount Armstrong, where the sources of the northern Waimakariri are situated, and of which I have described the principal features in the first part. Several cols, but of considerable height, Harman's Pass for instance, 3980 feet in altitude, separate it from Mounts Harman, Davie, and Greenlaw, a cluster of alpine peaks possessing considerable nevé fields, and giving birth to a number of true glaciers. Here the sources of the White river, the main branch of the Waimakariri, are situated on the eastern flanks; whilst on the southern slopes of the last-mentioned mountain, the principal source of the Avoca, belonging to the Rakaia system, issues, also from a glacier. On the western slopes of this cluster of peaks, the eastern head-waters of the Wilberforce take their rise, the northern slopes giving birth to the Taipo, the principal tributary of the Teramakau, and to the Arahura, both having a short and rapid course. Between these mountains and the western continuation (Mount Hall) Browning's Pass, 4752 feet high, is situated, it is difficult of access, and may be termed a true alpine pass. On the western side of Browning's Pass, the central chain rises again to a great altitude; it is called the Hall range, and its western summits above Browning's Pass have appropriately been named Twin Peaks. On the southern slopes of this range, a high saddle, which separates it from Mount Chamberlin, leads from one of the southern affluents of the Wilberforce into the head waters of the Kokatahi river, belonging to the Hokitika basin. It is, however, of no practical use. From here the Southern Alps run in page 180one longitudinal chain for about twenty-two miles, without any considerable break, to Whitcombe's Pass, 4212 feet above the sea level, the direction of which, like that of Arthur's Pass, is with the strike of the palæozoic rocks on both sides. The average height of the principal peaks in this chain may be estimated at about 9000 feet; they have mostly a pyramidical form, bold outlines, and glaciers of a smaller size than those met with more to the south, but still of the first order, descending from them far down into the valleys.^*

I may here add that from Whitcombe's peak, a high alpine range, the Lange range runs for a considerable distance in a northern direction, its eastern slopes augmenting the waters of the Hokitika considerably, whilst the glacier sources of the Waitaha are situated on the opposite side. The Wanganui, another important river of Westland, reaching the sea thirteen miles south of the former, issues from the glaciers which are formed from the vast snow-fields opposite the sources of the Rakaia, and which encircle the summits of Mount Ramsay and Mount Lyell, and the north-western slopes of the Tyndall range. The vast snowfields of Mount Tyndall, Mount Petermann, and the Keith Johnston ranges form the magnificent Grodley glacier, being in extent only second to the Tasman glacier. Mount Petermann, a sharp pyramidical peak, is separated on both sides by a deep nevé saddle from the two other ranges mentioned. Another important branch of the Godley glacier descends from the southern portion of the Keith Johnston and northern portion of the Hector range. From Mount Tyndall a divergent chain runs in a southerly direction, terminating at the junction of the Macaulay and Godley rivers; for about 18 miles it is covered with perpetual snow, having in Mount Forbes still a height of about 10,000 feet. From this chain, the Fitzgerald glacier descends to within half-a-mile of the Godley glacier, under which its outlet flows. On the western flanks, lie the Forbes glacier, the outlet of which falls into the Havelock; on the south slopes, several glaciers are situated which form the sources of the Macaulay, whilst some others of smaller extent reach into the upper waters of the Grodley river. Excepting Mount Cook, which is visible from the summits of Bank's Peninsula, from Lake Ellesmere and Southbridge as well as from Timaru, Mount Forbes is the only peak of the Southern Alps proper which can be seen from the Canterbury plains; it appears at the head of the large Ashburton opening as a sharp pyramidical peak.

I have already pointed out that Sealy's Pass, a nevé saddle of about 6000 feet altitude, leads from the Godley glacier into the head waters of the Whataroa, a rapid and large glacier river, reaching the sea about four miles north of the Okarito lagoon. It is important to note this fact, as it proves convincingly that owing to the enormous size of the Godley glacier, and the vast snow-fields from which it is formed, there is such a great amount of condensation of atmospheric moisture, and such a lowering of the mean annual temperature in this part of the Southern Alps, that the perpetual snow-line here descends considerably below 6000 feet. The Keith Johnston range on the southern side of Sealy's Pass, is separated from the Hector range by a high col; this latter range falls abruptly towards the Grey glacier, a tributary of the Godley glacier, whilst on its south-eastern slopes, large nevé fields feed the Classen glacier. At the southern end of the Hector range, Mount Beaumont rises, and from the West Coast stands out as a high rocky pyramid, with abrupt slopes and a nearly square summit; whilst, viewed from the Great Tasman glacier, it appears almost entirely enveloped in snow-fields of great extent, so that scarcely any rocks are visible. An important chain branches off from here, running to the south, separated from Mount Beaumont by a nevé saddle, about 8000 feet high. It first forms, on the southern side of the col, the Hochstetter Dome, the sides and summit of which are entirely hidden by snow-fields. This mountain is separated by a deep depression from Mount Darwin, a magnificent mountain about 12,000 feet high, resembling in its grand pyramidical form Mount Beaumont, as seen from the West Coast. Some of the principal glaciers of the New Zealand Alps have their origin here; the Tasman glacier from the south-western, the Classen glacier from the eastern, and the Murchison glacier from the southern slopes. The Agassiz glacier, and some other smaller glaciers north of it, descend from the western divide of Mount Beaumont towards the West Coast, forming the northern branches of the Waiau river. Between the Tasman and Murchison glaciers, lies the bold and picturesque Malte Brun range, appearing like an island, the Murchison glacier having at no distant date joined the former and thus surrounded this lofty snow-capped ridge. From Mount Darwin, the convergent range still continues its southern direction, where first in the Liebig range, the glacier sources of the River Cass, one of the affluents of Lake Takapo are situated, and then still further south in Mount Juke's, those of the river Jollie, one of the tributaries of the Tasman. From Mount Beaumont, the Southern Alps continue their south-westerly direction without interruption, forming the glorious peaks of Mount de la Beche, page 184Mount Haidinger, Mount Tasman; and last, but not least, their crowning summit, Mount Cook, the latter being separated from Mount Tasman by a rocky comb of considerable altitude. Numerous tributary glaciers descend from the eastern slopes of these peaks, of which the one between Mount de la Beche and Mount Haidinger, and another between Mount Tasman and Mount Cook, which I have named the Hochstetter glacier, are the most important; the latter forming one of the finest ice cascades imaginable. From the western flanks descends the beautiful Francis Joseph glacier, the main source of the Waiau river, of the principal features of which I have given some details in the first part. Another glacier of similar size, and descending to the same low region, is the Prince Alfred glacier; its outlet forms the main source of the Weheka, one of the principal rivers on the West Coast. Some other glaciers of considerable size also descend here from the western flanks of the Southern Alps, of which the Balfour glacier is fed by the snow-fields on the western flanks of Mount Cook.

I may here allude to the curious fact, that for a long time the identity of Mount Cook, as seen from the West Coast, was disputed, even officially by members of the Survey Department, they mistaking Mount Tasman (or what some still persist in calling the Dome) for Mount Cook, the peculiar orographical features of the ranges causing this mistake. We are so accustomed to see Mount Cook in its peculiar tent-like form from the east coast, when we observe it from or near Bank's Peninsula, or from Timaru, that when it appears to us as a sharp pyramid or needle, standing behind another mountain of a dome-like form, we fail, at first, to recognise it. However, the explanation is very simple:—Mount Tasman, situated so much more to the west than Mount Cook, hides the latter almost entirely, not only as seen from Hokitika, but its northern aspect when we look against the front, as it were, of its peculiar tent-like form, is so very different from its appearance as seen from east or west, when on or near the same latitude, that the explorer is easily deceived. However, when advancing south along the coast, we observe that the beautiful peak, which at Hokitika appears to the left of Mount Tasman, gradually shifts its position, so that near the mouth of the Wanganui river its highest summit stands in one line with Mount Tasman, so as scarcely to be recognised by a casual observer. Near Okarito, Mount Cook already stands to the left, but still appears to belong to the somewhat lower mountain in front; but at the mouth of the Waiau, the deep depression page 185between Mount Tasman and Mount Cook is well visible, the latter, however, here exhibiting the sharp needle form. Continuing our course still more towards the south this appearance gradually changes, so that on Gillespie's beach, south of the mouth of the Karangarua river, Mount Cook's form is the same as seen from the east coast, separated from Mount Tasman by a rocky ridge, which is so very steep that scarcely any snow can accumulate on it.^*

As before observed, from this peak the Southern Alps divide into two distinct chains, of which the western one runs in a nearly western direction to Mount Hooker; thence re-assuming the usual north-east and south-west line, as the Grey ranges, it reaches the lower course of the River Haast, which here cuts through this bifurcation of the central chain. On the southern banks of that river, it rises again above the perpetual snow-line till in Mount Kinross and to the west of Haast's Pass the two ranges re-unite. The eastern chain, forming the water-shed between the River Hopkins and the River Haast, is also of considerable altitude, numerous glaciers descending from it. First as the Ritter range, and afterwards as Mount Ward, Mount Napoleon and Mount Brewster on the eastern side of Haast's Pass, it rises high above the snow-line and has some peculiar, charming features, its lower portion being mostly covered with fine beech forest.

On the south-eastern slopes, the glacier sources of the River Hunter forming Lake Hawea, are situated. In the basin thus formed between this bifurcation, all the main branches of the River Haast take their rise; the principal one, the Landsborough, draining the vast snow-fields of Mount Ward, as well as those of the Ritter range. Between Mount Cotta and Mount Hooker, Docherty's Pass, about 5000 feet high, at the head of the Clarke river, is situated, discovered by Mr. W. Dockerty in 1864, and by which the explorer can descend to the sources of the Mahitaki river, and thus reach Bruce Bay. The western drainage of Mount Holmes and Mount Cotta is by the southern branches of the Karangarua. In the first part, I have already alluded to the principal characteristics of Haast's Pass (1716 feet above the sea-level), doubtless the lowest Pass across the Southern Alps throughout the whole Island. page 187Near it the sources of the Makaroa, falling into Lake Wanaka take theirrise, being formed by glacier streams of considerable size descending from both sides of the Southern Alps. On the western side in Mount Kinross, a fine dome-like peak, the latter continue to the southern boundary of the Proyince as Mount Alba, Castor and Pollux, Glacier Dome, and Mount Aspiring. They still rise to a considerable altitude, covered with perpetual snow; but it is very clear that the Alps south of the Moorehouse range begin to lose their continuity, being now broken into sharp pyramidical peaks, seldom attaining an altitude of 10,000 feet, with deep but generally inaccessible saddles between them. The river Makaroa receives a considerable supply of water by the Blue river, the Young, and the Wilkin, all of which drain the eastern slopes of the Alps. Near the head of the Young, or of the northwestern sources of the Wilkin, a Pass exists well visible from the West Coast, of which the Maoris gave me an account, but hitherto, as far as I am aware, it has not been reached by any European explorer.

Having now given a short outline of the orographical features of the Southern Alps proper, I wish to say a few words concerning the divergent chains, or secondary ridges starting from them and covering a considerable portion of the province. Again, beginning in the north at the Snowcup range, south of the Hurunui Pass, where the sources of the two main branches of the Hurunni and of the Poulter, a considerable branch of the Waimakariri, are situated, this mountain sends a chain in a southerly direction to Ashley Head. Here it bifurcates, the smaller branch, continuing the southern direction, terminates in Mount Thomas, the main branch continuing south-south-west as Mount Pember and the Puketeraki range to the gorge of the Waimakariri. This range is still 6,000 to 7,000 feet high, well visible from Christchurch, and abounds in splendid scenery, heightened by fine beech forest vegetation. East of the Upper Ashley, the mountains have more rounded outlines, they rise in the highest summits only to 3,000 or 4,000 feet, Mount Grey (3074feet) being one of the most conspicuous. Between the Waimakariri and Rakaia, the eastern continuation of Mount Greenlaw, is called the Black range, and a'though of considerable altitude, it does not reach the line of perpetual snows. It is separated from the Cragieburn range by a saddle named bale's Pass, (after its discoverer, Professor G. Sale), leading from the sources of the Harper into those of the Cass. The Cragieburn range, still rising to about 7000 feet, is remarkable by being in its upper and middle portion nearly devoid of vegetation, the whole sides forming an almost con-page 188tinuous talus of debris. This large range is separated from Mount Torlesse and the Thirteen Mile Bush range (Big Ben) by the valley of the Acheron, Lake Lyndon, and the valley of the Porter. These two fine ranges, separated by Porter's Pass, forming such a conspicuous object from the streets of Christchurch on a fine winter's day when they appear entirely covered with snow, may be considered the southern continuation of the Puketeraki range. The highest peak of Mount Torlesse is 6136 feet high, whilst Big Ben, the summit of the Thirteen Mile Bush range, reaches only an altitude of 5224 feet. Both ranges are covered on the eastern slopes with large beech forests, of which the upper limit is about 4500 feet.

I have already pointed out that the divergent chain, between the Upper Rakaia and Rangitata rivers, rises in Mount Arrowsmith, still high above the line of perpetual snow. This is the more conspicuous, as its eastern continuation has been cut off entirely by the remarkable broad plains, former glacier channels, which here unite the valleys of the Rangitata, Ashburton, and Cameron with that of the Rakaia. However, the cluster of mountains, which lies here to the east of this broad old glacier course, rises still to a considerable altitude, of which the highest summits of the Mount Somers range reach about 7200 feet, whilst Mount Hutt, forming such a conspicuous object, as viewed from the Canterbury plains, is 6800 feet high. This is the highest mountain rising directly from the Canterbury plains. From Mount Forbes, at the head of the Macaulay, a magnificent chain runs south, forming mostly pyramidical peaks, but not high enough for the formation of snow-fields to any extent. This range, which forms the western boundary of the upper Rangitata plains, is called the Two Thumb range from the peculiar form of its twin summits, appearing as if two thumbs had been put against each other. Its southern continuation, Mount Sinclair, is considerably lower, although still 7022 feet high; further south, on the eastern shores of Lake Takapo, it is called the Dobson range, where its highest summit has now an altitude of 6271 feet, falling abruptly to Burke's Pass, 2464 feet. On the southern side of this pass, the continuity of the range is much broken by several passes, such as the Mackenzie and Hakataramea Passes, all former glacier channels for the enormous ice masses of the great Waitaki glacier during the great New Zealand Glacier Period, here passing over and between the ranges, which have lost much of their altitude and are worn down and rounded off, as observed in all glacialized countries. More to the south, longitudinal ranges, still 5000 to 6000 page 189feet high, rise from the Hakataramea Pass, between this river and the lower Mackenzie plains to the Waitaki, another from the Mackenzie Pass to Mount Nimrod, where it subdivides, of which the western branch, running between the Hakataramea and Waihoa, reaches the northern bank of the Waitaki, whilst the eastern one, under the name of the Hunter range, finds its termination near the Waimate.

I have repeatedly alluded to the Great New Zealand Ice Period, or Glacier Epoch, and as this remarkable era plays such an important part in the Physical Greology of New Zealand, I may be allowed here to make a few remarks upon it for the general reader, the more so as there are scarcely anywhere alpine countries so easily accessible for the scientific observer, bearing such clear and distinct traces of the post tertiary Grlacier Period, as the Alps of New Zealand. The action of the giant ice ploughs, as we may well call these glaciers, has essentially assisted in preparing the lower regions for the use of man, since by it the narrow valleys have been widened, the rugged mountains rounded off, and large plains have been formed. Thus we find everywhere, as soon as we penetrate into the New Zealand Alps, where even the outrunning ridges near the plains often attain a height of 6000 feet, that the valleys are distinguished by rugged forms, where the rivers which break through them have not only cut their bed deeply into the rocks, but have also formed such steep precipices that it is often impossible, even for the pedestrian, to pass along their banks, in order to reach the alpine lakes or plains situated in the valleys above. Inside of the eastern divergent chains, as soon as we enter the district of the earlier post tertiary glaciers, the valleys widen out to broad basins, the mountains on both sides—or even standing in the middle of the valley—have the recognised roche moutonnée, or ice-worn roundedhill form, and the fall of the rivers is less rapid. At the upper end of these fiats, which are filled up with drift, alluvium, and glacier deposits, and through which the rivers have cut their new bed, lakes, surrounded by distinct moraines, are generally situated. The regular occurrence of these earlier terminal and lateral moraines supply us with the incontestable evidence that these lakes have been formed by the retreat of the glaciers. These lakes are found in every possible stage; some have already disappeared, the delta of the principal tributary entering from the Alps having completely filled them up; others are very much contracted by the deltas of the main affluent and of the secondary water-courses descending from both sides; others again are great page 190swamps, having become so shallow, through the enormous quantity of glacier silt deposited in them, that they also may soon disappear under the continually advancing masses of debris.

The extent of these flats, and of the lakes in them, stand in almost all cases in exact proportion to the extent of the present glaciers at the end of the valley, and, therefore, of course to the height, extension, and other orographical conditions of the alpine chains. The form and width of the valleys above the alpine lakes show in the most striking way that they must have once been the bed of great glaciers, to the action of which they principally owe their present form. They are frequently, even up to the present glaciers, of the same width as the lakes. On both sides of them, several thousand feet above the level of the valley, enormous moraines are found stretching along the mountains, so that one can often follow the terminal moraine at the lower end of the lake for twenty miles upwards. Roches moutonnées occur everywhere. However, where the colossal glaciers of the Ice Period have pierced through to the Canterbury plains, the secondary ridges are also rounded off and the valleys widened.

In the valleys several miles wide, the present rivers flow in numbers of branches, uniting and separating a hundred times, and changing their bed after each great fresh. At the same time they are often so straight, that one can see the glaciers from the lakes, as is the case, for example, at Lake Pukaki, from which the Tasman glacier, and Lake Takapo from which the Classen glacier can be seen. Indeed it does not require much power of imagination to bring before one the time when the glaciers were often fifty to sixty miles long and six to ten miles wide. In one of my official reports "On the formation of the Canterbury Plains," I have given a detailed description and explanation of these interesting and important physical geological conditions.

In order to understand the former occurrence of the great postpliocene glaciers, we have to assume no change in the climate, but simply to consider the existence of the plateau-like mountain systems towering above the snow-line, the enormous snow masses of which might be sufiicient to explain the existence and extension of the glaciers. A comparison with the Dovrefield in Norway might perhaps not be out of place here. I have also tried to show that the terrace formation which we meet with everywhere, even in the valley of the most unimportant streamlet, has not been brought about by an upheaval of the land, but only and entirely by the retreating of the sources and page 191the gradual deeper washing out or excavation of the valleys. I have already remarked that most of the principal valleys contract before they enter the Canterbury plains from the lower Alps, but some of those which, in the Ice period, lodged particularly large masses of glaciers, form an exception to this rule. I will only quote one as an example: the Rakaia valley, which continues to widen without interruption until it enters the Canterbury plains, where it has attained a breadth of five miles. This is, however, quite natural when we find the last terminal moraine on the Canterbury plains themselves, where it extends over them in a half circle for ten miles, and shows clearly that the ice masses of this glacier were so enormous, that when they came out into the open plains they were able to extend into the form of a gigantic fan. It is, therefore, a matter of course that along the whole valley, from the sources of the glacier to the plains, not only the mountain sides exhibit signs of glacier action and are fringed by moraines of great extent, but that also the mountains in the valley itself must possess the roche moutonnée form. Indeed the shape of those in the neighbourhood of Lake Coleridge, a true glacier basin, is so peculiar that they have been named "sugarloaves," and the colonists mistook them to be volcanic cones, until I was able to make them acquainted with the real cause of their peculiar form. Thus the Southern Island of New Zealand owes it principally to the Ice Period that, united to the North Island, it can lay claim to the title of "Britain of the South," because by its operations have been formed the magnificent plains for agriculture, and the rounded hills and mountain sides so favourable for depasturing cattle and sheep. I have taken the liberty of making this digression, in order to explain the peculiar conditions which surround the traveller the farther he penetrates into the heart of the Alps, and which would remain a mystery to him had not geological researches supplied the key to their explanation.

The divergent ranges between the Takapo and Pukaki systems, although very high, are not extensive as they terminate at the northern boundary of the Mackenzie plains. The rivers Cass and Jollie have their glacier sources amongst them. Whilst this latter range consists of three parallel chains, the high mountain range which begins east of the rocky saddle between the Moorhouse and Sealy ranges, has only one water-shed, the eastern side draining into the Tasman and the western into the Dobson river. It is nearly forty miles long, and many peaks of its northern portion are covered with perpetual snow. As the Ben Ohau range, where it has lost considerably in its altitude, it slopes to the Mackenzie plains, near the outlet of Lake Ohau.

I have already given a description of the bifurcation of the Southern Alps south of Mount Holmes. The eastern chain at Mount Ward, a prominent peak, subdivides again and forms two large ranges, of which one, after skirting the western shores of Lake Ohau and forming the western boundary of the Mackenzie plains, ends six miles south of that lake. It is separated from the western range by the River Ahuriri, one of the tributaries of the Waitaki; this western range, also of considerable altitude, crosses into the Province of Otago, and after being intersected by a saddle called Lindis Pass, it continues as the Dunstan range to the junction of the Mauuherekia with the Molyneux. On the western batiks of the River Hunter, which washes the western foot of the last mentioned chain, the Young range rises and forms the southern continuation of Mount Brewster. It runs along the eastern banks of the Makaroa river, and of Lake Wanaka, where, gradually getting lower, it comes to a termination near the southern end of the lake. There is only oue mountain system in the Province of Canterbury which is not connected with the central [unclear: chau], namely, Bank's Peninsula; this system, even iu quaternary times an island, was joined during the formation of the lower portion of the Canterbury plains to the main land. It rises to a considerable altitude, Mount Herbert being 3100 feet high. It abounds in deep indentations, ancient volcanic craters, of which several form remarkably fine harbours. Some of the western indentations, such as Lake Forsyth with the valley of Little River, and the Kaituna and Grebbie valleys, show clearly by their configuration that they owe their present form to marine action.