Marshall, Speight, Cotton. — Younyer Rock-series of N.Z. 393 



rocks were deposited. He has, however, up to the present been unable to 

 find any stratigraphical break, and the occurrence of the coal pebbles may, 

 in the meantime at least, not unreasonably be ascribed to contemporaneous 

 erosion, or even in many ^ases to the inclusion of wood-fragments in the 

 sediment. 



The coal-measures of Pakawau have been placed by Hutton in the 

 Cretaceous. This is apparently based on the occurrence of fossil plants 

 and on the nature of the coal. One of us has carefully examined the 

 ground, and has formed the opinion that in that locality no unconformity 

 separates the coal-measures from the overlying rocks of admitted Cainozoic 

 age. This is in accord with the opinion of Park, who in 1890 classed no 

 beds but the Cretaceo-tertiary as lying between the glacial matter and 

 Palaeozoic strata.* Cox, in 1883, had described a Lower Greensand 

 formation as lying below the Cretaceo-tertiary series, but makes no mention 

 of a break.f 



Poverty Bay. — In the Poverty Bay district a complete series of Creta- 

 ceous and Tertiary rocks has been described by McKay.J This district 

 has, however, lately been worked in detail by Adams, § who classed all the 

 rocks of Upper Miocene age, stating that no marked unconformity was 

 observed between any of its members. One of us has examined the sections 

 in this area in great detail, and is positive that no unconformity was shown 

 in the many miles of continuous sections displayed. 



Shag Point. — Here Hutton, 1| Haast,^ and Park** have described an 

 unconformity, but in different localities. McKay,f f in 1886, showed clearly 

 that Hutton's and Haast's break was really due to a fault, as stated pre- 

 viously by Cox. The imconformity referred to by Park is a matter of 

 inference, and is placed in the middle of the Shag Estuary, where no rocks 

 crop out at the surface. One of us visited this district, but was not able 

 to go over the ground in any detail. No evidence of an unconformity was 

 found as a result of the examination made on this occasion. The rocks 

 are here somewhat more folded than usual, and it is natural to hesitate 

 to allow the presence of an unconformity until the effects of faulting and 

 folding have been fully set out. This was done by McKay, and, we believe, 

 with considerable success in showing that such structural features satis- 

 factorily accounted for the position of the various outcrops. 



(d.) Oamaru District. 



The variety of opinion in regard to the relation of the rock-series in the 

 very clear sections of North Canterbury becomes still more confusing when 

 attempts are made to correlate with the Canterbury series the younger 

 rock-outcrops occurring elsewhere (see fig. 7). This is particularly true 

 of Oamaru, where there is a clear series with quartz gravels at the base 

 and marly shell beds at the top. The different members of the series are 

 shown in the accompanying diagrams. In this series Hector inserted two 



* Park : Rep. Geol. Surv., 1890, p. 229. 



tCox: Rep. Geol. Surv., 1883, p. 71. 



% McKay : Rep. Geol. Surv., 1886, p. 192, map ; also Geol. Explor., 1900-1, p. 23. 



§ J. H. Adams : N.Z. Geo!. Surv. Bull. No. 9 (n.s.), p. 12. 



II Hutton : Geol. of Otago, 1875, p. 46. 



H Haast : Geol. Rep. 1873-74, p. 24. 

 **Park: Geol. of New Zealand, 1910, p. 116. 

 ft McKay : Geol. Rep., 1886, p. 22. 



