312 Transactions. 



been obtained from almost the bottom to the top of the series, and have 

 been pronounced by Woods (1917) to belong all to one fauna, which he 

 correlates with the Lower Utatur group of India, which is of about the 

 same age as the Upper Gault and Upper Greensand of England — i.e., Albian. 

 Moreover, all other fossils from rocks having the same relative position 

 in both the Middle Clarence and Awatere Valleys are, according to Woods, 

 of sinailar age, so that the inclusion of all these rocks under one group- 

 name is justified, although the total thickness of the Clarentian at Coverham 

 surpasses the whole of that of the Notocene in places such as the Waipara 

 district, where rocks from Senonian to Pliocene are represented. This 

 is probably due to the fact that the Clarentian deposition followed close 

 on the post-Hokonui orogenic movements, and erosion on a fairly emergent 

 land-mass was still active. Probably also the Coverham area was not far 

 from the mouth of a large river. 



The Clarentian rocks, while preserving for the most part the same 

 general character of sandstones and mudstones, vary rapidly from place 

 to place, and there is no single characteristic stratum which can be followed 

 from end to end of the valley. There are, nevertheless, some notable 

 differences in the rocks at the two ends of the valley. The rocks at Cover- 

 ham are dominantly black mudstones with occasional calcareous con- 

 cretions, divided into three main groups by sandstones, and resting on 

 conglomerates. In the Herring River, and thence nearly to the Bluff River, 

 the sequence commences with terrestrial coal-measures, followed by several 

 lava-flows, and these are succeeded by a marine series of sulphurous mud- 

 stones, sandstones v.dth pebble-beds, loose sands, and giauconitic sandstones. 



Coverham (Plate XXV, fig. 1). — I have suggested the following division 

 of the sequence at Coverham (Woods, 1917, p. 2), but it must be clearly 

 understood that this classification has a strictly local application : — 



Feet. 

 Sawpit Gully mudstones . . . . . . . . 3 , 200 



Nidd sandstones and mudstones 

 Cover Creek mudstones 

 Wharf Gorge sandstones . . 

 Wharf mudstones 

 Basal conglomerates 



c 



550 

 2.000 



450 

 1,500 



250 



The conglomerates were examined in a tributary of the Wharf Stream 

 coming from the Sawtooth Range, where they strike at the base X. 40° E., 

 dipping at 45° to the north-west, and near the top strike N. 60° E., with dip 

 60° to north-vv'est. The underlying pre-Xotocene greywackes and argillites 

 strike X. 20° W., with a steep dip to the north-east. The unconformitv is 

 well exposed in section (Plate XXV, fig. 2). The conglomerates are, in part, 

 of a peculiar character, not uncommon elsewhere in the Clarentian — viz., 

 that they consist of well-rounded pebbles, a few inches in diameter, of 

 hard rocks such as quartzite, set in a matrix of mudstone. The con- 

 glomerate series at this point commences with beds of hard conglomerate 

 alternating with this pebbly mudstone, then some layers of pure mudstone, 

 and then more bands of pebbly mudstone, the whole being about 250 ft. 

 in thickness. The conglomerate consists mainly of well-smoothed ellip- 

 soidal pebbles of hard sandstone and quartzite, up to Sin. long, but 

 mostly with a major diameter of 3 in. to 4 in., with only a few pebbles of 

 mudstone and soft sandstone near the base. Green and liver-coloured 

 quartzites are relatively rare, but white quartz and bright-red and pink 



