568 Transaetions.—G eology. 
Maungaharuru Sandstones. 
Lying on the lower Papa is found a vast series of hard sandstones and 
gritstones, with thin strata of limestone composed of rolled fragments of 
shells and interbedded bands of Papa. This sandstone bears a great resem- 
blance to that of Waikaremoana, being equally hard, and generally of the 
same colour, although it is sometimes varied by bluish and yellowish varie- 
ties, 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 out- 
crop 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 ¢liffs 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 upper- 
most 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 forma- 
tion 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 lime- 
stone 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 sand- 
stone, the bottoms of which are occupied by streams, ponds, patches of 
bush, and numerous waterfalls, forming altogether a most picturesque 
country. 
Pohue Papa. 
We have now arrived, in our upward course, at a point where a consider- 
able break occurs in the sequence of the beds, which is plainly seen where the 
two formations meet. Section 2, Plate XXIII., exhibits the unconformability 
of the beds as seen 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 
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