Art. VI.—Some Striated Stones from the St. Bernard Saddle, Upper Waimakariri Valley.

By M. C. Gudex.
Communicated by R. Speight.

[Read before the Philosophical Institute of Canterbury, 2nd September, 1908.]

Although almost all proofs of glaciation are frequently met with in New Zealand, it is remarkable that the discovery of ice-striated stones has been seldom recorded. In 1904 Mr. E. G. Hogg^* recorded his discovery of striated stones at Lake Wakatipu.

The St. Bernard Saddle is really the terminal moraine of an old glacier which came down the valley of the Bealey over the Goldney Saddle and rounded the hill west of the Cass River. All the surrounding country bears unmistakable evidence of having been subjected to glaciation, for small lakes, roches moutonnées; moraines, and glacier-terraces are to be seen on every hand. Probably the most remarkable feature to be seen from the Saddle is a series of glacier-terraces high up on the slope of the hill to the right; all are parallel and dip slightly to the south, thus showing the direction of the glacier's motion. The St. Bernard Saddle, which is the most characteristic moraine, is well exposed in section in a great many railway-cuttings, shingle-pits, and road-cuttings. A typical section^† shows that this moramic débris has been assorted by the action of streams flowing from the glacier, for the current-bedding is well defined. The angular nature of the boulders, however, shows that they cannot have been carried far by streams. A careful search among the stones thrown to the sides of the cuttings reveals many good specimens of striated stones of all sizes. They are usually composed of greywacke, but sometimes they are composed of blue slate. They possess a characteristic oval or round shape with parallel striae, and this is decisive proof of the nature of their origin. The late Captain Hutton once expressed the opinion that few striated stones would be found in Canterbury; but the opening-up of the shingle-pits and cuttings at the St. Bernard Saddle has exposed many good specimens. These stones are an additional proof of the former glaciation of the Upper Waimakariri Valley.