12 Transactions. 



in thickness, and finally reached granite at a depth of 1,421 ft. The 

 brown coal of the district is at a considerably higher horizon, and may or 

 may not be separated from the pitch and bituminous-coal series by an 

 unconformity. At present no evidence for discordance other than overlap 

 and analogy with areas farther south can be brought forward. 



2. Westport District. — -The writer has lately published evidence in favour 

 of an unconformity (disconformity) between the Oamaru Series of approxi- 

 mate Miocene age and the bituminous-coal measures of probable Eocene 

 age (58, pp. 271 et seq. ; 62, pp. 58-88). Angular discordance (clino- 

 unconformity) between the two sets of strata has not been observed, and 

 the most striking evidence of a stratigraphical break consists in the presence 

 of numerous pebbles of coal and carbonaceous shale, derived from the bitu- 

 minous-coal measures, in the basal and occasionally in the higher beds 

 of the Oamaru. The latter series widely trangresses the Eocene strata, 

 in such a manner as might well be considered proof of unconformity were 

 it not that New Zealand conditions are so peculiar that overlap alone can 

 hardly ever be regarded as a decisive criterion. In at least two localities, 

 however, upper Oamaru beds rest on the Eocene beds to the exclusion of 

 the lower portion of the Oamaru formation (58, p. 275 ; 62, pp. 92-93), 

 and at the mouth of the Fox River Miocene strata unconformably overlie 

 a breccia conglomerate correlated with the Hawk's Crag breccia, the lowest 

 member of the bituminous-coal measures (58, pp. 274-75). 



3. Greymouth District. — Von Haast in 1861 evidently thought that the 

 series of rocks having the Cobden limestone as its upper member rested 

 unconformably on bituminous-coal measures (18, p. 109), and this view 

 was quoted with approval by Hutton in 1887 (29, pp. 268-69). In 1873 

 McKay discovered strata containing detrital coal, which at that period he 

 thought were below the Cobden limestone and were indicative of uncon- 

 formity with the coal-measures (3, pp. 77 et seq. ; 35, p. 7). In 1901, 

 however, he placed the detrital-coal beds above the Cobden limestone 

 (35, p. 8), an horizon where he considered there was independent evidence of 

 a stratigraphical hiatus. In 1909 and 1911 the writer showed that McKay's 

 original view was the correct one (43, p. 13 ; 46, pp. 63, 66, &c.), and in 

 the course of field-work found that no break of any kind existed above 

 the Cobden limestone in the Greymouth district.* As at Westport, angular 

 discordance has not been detected, and the chief evidence for unconformity 

 between the writer's Greymouth Series (equivalent to Oamaru and Pareora 

 beds) and the bituminous-coal measures of Eocene age consists in the pre- 

 sence of immense quantities of detrital coal in the lowest, or Omotumotu, 

 beds of the Greymouth Series, as originally announced by McKay. In 

 1911 Marshall, Speight, and Cotton regard the evidence as inconclusive 

 (47, pp. 392-93), and in 1912 Marshall, writing alone, takes the same view 

 (55, p. 68). 



4. South Westland. — Rocks of Tertiary or possibly in part of Cretaceous 

 age have been described by Cox and vpn Haast as occurring near the 

 mouth of the Paringa River. Owing to the presence of a conglomerate con- 



* McKay at one localitj^ observed a difference of strike between the Cobden lime- 

 stone and so-called nummulitic limestone (3, p. 7.5). The writer examined the same 

 locality, and came to the conclusion that a fault or other disturbance accounts for 

 the discordance of strike, which is not very great. The " nummiditic " limestone is 

 really an Amphistegina limestone (46, pp. 68, 71). At Greymouth a clear and con- 

 tinuous section shows it in perfect conformity with the Cobden limestone. 



