126 PKOCEEDIXGS OF THE GEOLOGICAL SOCIETY. [DeC. 7, 



schists apparently lie very flat, and cover a great extent of country. 

 The foliated quartz does not commence at a distinct horizon, but 

 beds thus altered occur in, the regular sequence of the strata sepa- 

 rated by quartzless rock. In the lower part of the series, however, 

 as exposed in the deep valley of the Clutha River, that cuts right 

 through the central district of the province, the whole mass of the 

 schist is intersected by concretionary laminae of quartz (generally of a 

 bluish tinge and horny appearance), that conform to the planes of 

 foliation, as in mica-schist. Gold occurs segregated in the inter- 

 spaces of this contorted schist, but it is rarely found in situ. 

 Quartz-reefs are confined to the npper schists, but there are very 

 few instances of true " fissure-reefs" having been discovered, that 

 is, reefs that cut the strata nearly vertically, and have a true "back" 

 or wall independent of the foliation-planes. Only one reef is being 

 worked in the same manner as in Victoria as yet, and the yield is 

 about 1 oz. to a ton. I have nowhere seen in this Province the 

 exact mineralogical equivalents of the auriferous slates of Victoria 

 or California, as they resemble much more those of British Columbia. 

 I believe the difference is due to the absence of true cleavage, and 

 its having been replaced by foliation and joints ; so the same in- 

 ternal changes by chemical action, due to infiltration, have not 

 taken place, — that is, supposing, as I do, that both these, namely, 

 cleavage-planes on the one hand, and the foliation and jointing on 

 the other, have been due to mechanical impulse, followed in the 

 first case by the segregation of the siliceous matter in distinct veins, 

 and in the other in the form of laminae. In the one case the me- 

 chanical force has plicated the strata ; and the cleavage-planes 

 have the nature of fissures, and may be compared to the joints 

 of the foliated strata. In these the shales have moved on their 

 planes of stratification, commencing afresh at each line of joint. 

 In either case, a system of drainage is established in the schistose 

 rock, which facilitates the segregation of its mineral elements. 



External to all the above formations we have a series of Tertiary 

 rocks ; the lowest of these, however, may possibly be of Upper 

 Mesozoic age. The series consists of coarse conglomerates, sand- 

 stones, and shales, containing estuarine shells, and associated with 

 thick deposits of brown coal (e), of excellent quality. The shales 

 with the coal contain Ferns and Dicotyledonous leaves. This carbo- 

 naceous formation is generally tilted at considerable angles, and is 

 unconformably overlain by the Newer Tertiary rocks. These consist 

 of two series, the one freshwater (d), occupying basins or depressions 

 in the schistose rocks of the interior, the other marine, confined to 

 the coast-Hne and low altitudes. The relation of these one to 

 another cannot be distinctly made out, but I think that some at 

 least are contemporaneous. The lower marine beds are argilla- 

 ceous (c), and contain septaria, sometimes of an immense size, as in 

 the case of the Moeraki boulders*, which are quite spherical, and 

 often reach 12 feet in diameter ; they are washed out of this forma- 



* See Mr. W. Mantell's description and figures, Quart. Journ. Geol. Soc. 

 vol. vii. p. 324. 



