Extent.

Starting from the northern boundary of the former united Province of Canterbury, this zone begins below the junction of the Otira with the Taramakau, where it covers a rather narrow belt of country page 261situated entirely along the western watershed of the Southern Alps. Gradually it becomes broader, and, near Browning's Pass, crosses to the eastern side of the central chain, whence it continues to be largely developed as far as Whitcombe's Pass, the rocks on the western side of the Pass included. The summits of the Southern Alps continue to be generally formed of rocks belonging to this zone, till we reach Mount Cook, which consists of beds pertaining to the next, or Mount Torlesse formation. South of Mount Cook, in the Sealy range, the Waihao formation again becomes greatly developed, now increasing much in breadth, and being divided into two portions by beds of great thickness overlying them, which appear principally in the River Hunter, the eastern belt of the Waihao formation being the narrowest one. Another zone of the same formation enters the Province of Canterbury from the south, between the junction of the Hakataramea with the Waitaki and the mouth of that river, consisting of a series of [unclear: range] from 2,000 to 3,500 feet high, which are the apex of an anticlinal or saddle-back arrangement. They sometimes appear as high table-land, into which the rivers have cut deep gorges, and are bounded and overlaid on both sides by younger rocks. These younger rocks rise to higher mountain chains, on the eastern side as the Hunter, on the weatern as the Hakataramea ranges, situated on the right or western bank of the Hakataramea river. They continue as far as Fox Peak on the western side of the Opuha plains, getting gradually narrower where they disappear below beds belonging to the Mount Torlesse formation. Small outliers occur on both banks of the Pareora, Opihi, and Kakahu rivers, about their middle course. Judging from the lithological character of the altered beds occurring there, another outlier exists in Banks' Peninsula.