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of their waters is in great measure due to the stirring up of the deposits of fine glacial sediment, brought down by the rivers. This affords, moreover, additional evidence of the shallowness of these lakes. But if stronger proofs were wanting, it is to be found in the circumstance that after strong winds the water of their outlets becomes filled up alternately with exceedingly white, from finely suspended whitish glacial mud or ferruginous sand and clay. These strata vary in thickness from four inches to five feet, and strike nearly north and south with a dip towards the west of 23 deg. These beds have been denuded for about 70 feet above the river, and are capped by 30 feet of boulder and boulder clays, having a rough horizontal stratification.

About 60 feet above the present level of the lakes we meet with shingle beds, which have evidently been assorted by the action of the waves. In other places to which the prevailing winds have had more access, the waves have eaten into the shores, and landslips have taken place, which present successive layers of fine flour-like whitish sediment, similar to that which is now deposited between the rocks in well sheltered places. Now and then small layers of a coarser nature and darker colour are met with, interstratified with these finer deposits. I also observed inclosed, in the first described sediment, large, well-rounded boulders, whilst the occurrence of a single large angular block, embedded in the glacial mud, was rather perplexing.

Further proof of the former higher level of the lakes is to be inferred from two breaks in the moraine wall, one 60 and the other 100 feet above the present level, through which the waters formerly flowed. Corresponding with these openings (called lake-passes by the settlers) we find in the plains below them, small dry channels, evidently the former courses of the waters which flowed from these branch outlets.

Although at first sight we might suppose that only one subsidence of the land took place, by which it was sunk for many thousand feet below the sea level (followed as a consequence by the glacial period), yet, on closer examination, I was led to a different conclusion.

I observed, for example, in several places deposits of newer glacial drift, lying unconformably upon older deposits of a similar character, one mound (showing these older deposits and rising above the level drift plains which stretch between the old moraine walls surrounding lakes Pukaki and Ohou), is so conspicuous, that I shall offer a short description of it. This mound lies on the edge of a small rivulet descending from the ranges between the two lakes. It is about one hundred feet high, and its base, on the side of the rivulet, is being gradually washed away. By the fall of the superincumbent mass, a nearly vertical bare cliff has been exhibited, of which the strata, for about 70 feet upwards, consist of many distinct layers of boulders; the interstices filled up alternately with whitish glacial mud or ferruginous sand and clay. These strata vary in thickness from four inches to five feet, and strike nearly north and south with a dip towards the west of 23 deg. These beds have been denuded for about 70 feet above the river, and are capped by 30 feet of boulder and boulder clays, having a rough horizontal stratification.

I am not prepared to give a satisfactory explanation of this phenomenon, but may suggest, that although not many proofs are to be found of successive or regularly recurring changes in the level of the island during which the deposits of the great boulder formation have been formed, this one fact would point to the possibility of such an occurrence. And may we not assume, considering the loose character and great similarity of the deposits of the post-pliocene period, that it would be extremely difficult to determine, from their appearance alone, whether they had been formed during the period of a single or during those of several successive depressions.

The above described isolated mound clearly points to more than one period of subsidence, and I hope to be enabled, by further investigation, to bring forward additional evidence on this point.

Assuming that the rise of the country still continues, and that the lakes must ultimately be filled up, the rivers, which now supply them would flow through channels formed in their beds.

The further upheaval of the island would lead to the occurrence of similar phenomena to those observed in the valley of the Rangitata, where the more rapid fall of the water has partly removed similar lacustrine deposits, not only along the main channel, but also at various points at the bases of the neighbouring hills, where lateral deltas had been formed, which were afterwards, during a later period of subsidence, overlaid by boulders and boulder clays.

It is perhaps presumptuous to offer any remarks on this subject, before further study and investigation, but the wish to elucidate, and to suggest similar observations in the northern hemisphere, has led me to notice it.

I have the honor to be, Sir,

Your most obedient servant,

JULIUS HAAST