Page:Transactions NZ Institute Volume 9.djvu/614

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Lying on the lower Papa is found a vast series of hard standstone and gritstones, with thin strata of limestone composed of rolled fragments of shells and interbedded bands of Papa. This sandstone bears a great resemblance to that of Waikaremoana, being equally hard, and generally of the same colour, although it is sometimes varied by bluish and yellowish varieties, more especially in its upper parts, where it is also much softer. They extend from Maungaharuru to the Waiau river, where they are lost to view, having apparently suffered great denudation, and are covered by the next formation, until some 25 miles to the north-east they again occur at Te Reinga, the point where the Wairoa River precipitates itself over their outcrop in a magnificent fall. Continuing on to the east they compose the lower part of the Whakapunake range, attaining an altitude above the sea of 3,198 feet, and forming some grand perpendicular cliffs facing the east or seaward side of the basin. From here they tend to the south-east and south, finally reaching the sea coast near Nuhaka, where however the uppermost beds only are seen, composed of soft yellowish sandstone containing many fossils. At Nuhaka, the Papa is seen immediately to the east of these sandstones, but there is some doubt as to whether it belongs to that formation already described or to the middle Papa, which overlies the sandstones to the south-east. It contains some of the same cement stones. The question will ultimately depend upon the presence of the same fossils, but as I obtained none, either here or in the southern part of the lower Papa, the matter must at present remain an open question. The bands of limestone occurring with these sandstones are composed almost entirely of broken and rolled fragments of shells, principally of the genera Pecten, Ostrea, and Waldheimia. The dip of the beds varies from 17° to 29° 30′, being greatest on the slopes of Maungaharuru. Here the surface of the country is broken up into deep gorges with perpendicular sides of grey sandstone, the bottoms of which are occupied by streams, ponds, patches of bush, and numerous waterfalls, forming altogether a most picturesque country.

We have now arrived, in our upward course, at a point where a considerable break appears in the sequence of the beds, which is plainly seen where the two formations meet. Section 2, Plate XXIII., exhibits the unconformatibility of the beds as see on the Upper Waikare stream, where the Papa, dipping at about 10°, abuts against the steep face of the sandstones, dipping under them at an angle of 29° 30′. This unconformability is a marked feature in viewing the country anywhere near the line of strike of the beds, where the older strata, even in places where the sandstone (as I suppose) has been