402 " Transactions. 



Zealand are all of the same age." " At the base of the group with a Tertiarv 

 facies " (p. 325). 



" Notes oil the Coalfields of New Zealand " (Proc. Inst. Min. and Met., 

 vol. 8, 1899, ]). 148) : " All the workable seams of coal are found in mea- 

 sures of Lower Eocene age." " Coal never has been, and never will bo. 

 found below Amuri limestone " (p. 150). 



"Age and Relations of New Zealand Coalfields "' (Trans. N.Z. Insl.. 

 vol. 36, pp. 411, 418, 1904) : Cretaceous coals (below Amuri limestone) : 

 VVaipara series — Pakawau, Mokihinui, Westport, Greymouth, Malvern 

 Hills, Shag Point. Miocknk : Oamaru series — All the other coal-seams, 

 of which seventeen are enumerated. 



Proceedings N.Z. Inst., 1909, ]). 59 : The Clreen Island Coalfield is 

 classed as Mesozoic. 



" Geology of New Zealand," 1910, p. 293 : Ui'PKR Crktaceous : Wai- 

 PARA — Shag Point, Kaitangata, Malvern Hills, Kawakawa, Hikurangi, 

 Ngunguru. Waimangaroa series: Eocene — Grey, Paparoa, Westport, 

 Mokihinui, Pakawau. Oamaru series : Miocene — Taupiri, Waipa, Mokau, 

 West Wanganui, Inangahua, Mount Somers, Kakahu, Waihao, Ngapara, 

 Waikouaiti, Green Island, Forest Hill, Nightcaps. 



Thus, to take a single example, he has classed the Kaitangata coal as 

 Lower Tertiary in 1888, Lower Eocene in 1899, Miocene in 1903, and 

 Cretaceous in 1910. 



Our observations have led us to the opinion that the coal is always at 

 the base of that development of the series of younger rocks that happens 

 to be present in any district. Since, owing to the great overlapping of 

 the higher beds of this series, the base in any locality may be of any 

 age between the Cretaceous and the Miocene, it is evident that the coal 

 in particular places may be in any part of the Eocene, 01igO(;ene, and 

 perhaps occ'asioually Miocene system. It is therefore, in general, useless 

 to classify the fossils and assign the shell-bearing strata to any definite 

 period as a preliminary to a search for coal. It is only necessary to deter- 

 mine the depth of the base of the series, for it is there that coal may be 

 found, whatever the age of the base of the series in that locality may be. 

 It has been recognized by all authorities that individual coal-seams ai'e 

 not widely extended, and the fre(]uent presence of quartz or other pebbles 

 in them suggests detrital origin. It is therefore evident that general prin- 

 ciples cannot hei'e be used in predicting the occurrence of possible coal- 

 seams. Prospe('ting in each separate locality is necessary, for detailed 

 stratigraphical methods are in the main useless. 



The opinion that is here expressed is strongly supported by the acknow- 

 ledged absence of seams of coal in any horizon above the basal- conglome- 

 I'ate in any section. If coals had been formed in imconformable series, it 

 is not unreasonable to suppose that seams would be found in some localities 

 in two different formations at different levels. This has not yet been found. 



(iii.) Greensands. — The greensands at the Waipara and Amuri Bluff 

 were apparently deposited under somewhat exceptional conditions. Though 

 containing little or no pyrite, they liberate large quantities of sulphuretted 

 hydrogen from the natural exposures in cliffs, and in many places there 

 is an effloresence of sulphur formed on the surface of the sandstone in some 

 quantity. 



The associated gi'cy and white sands are also alnu)st entirely formed 

 of quai'tz, and the same remai'ks apply to them. The greensands are of 



