Canterbury and Westland. 465 



There are some white plastic clays in the Oamaru formation, as for 

 instance in the valley of the Kakahu river, and in the Waihao basin, 

 which some day will also be extensively used for manufacturing 

 purposes. 



Sands. 



In some former chapter mention has been made of the fact, that 

 large beds of quartzose sands exist in our younger formations, the 

 Waipara formation containing the richest deposits. Generally, they 

 are not quite pure, having some slight admixture of clay, iron, and a 

 few other mineral substances. There are, however, several of these 

 layers of a snowy white colour, being an exact counterpart of the 

 sands of the Brown coal formation in E-henish Prussia ; and as the 

 sands of that country are derived from the decomposition of quartzose 

 trachyte, so the sands of our brown coal beds are portions of decom- 

 posed quartziferous porphyry. These sands in Germany are of great 

 value for the manufacturing of glass, and are extensively used for 

 that purpose, and it is worthy of notice that some of these sands, when 

 of great purity, such as those of Bardenberg, Herzogenrath, and 

 Nievelstein, are exported in great quantities to Great Britain for that 

 industry — (Zinken, Braunkohle, Yol. I, page 600). In Bohemia, too, 

 many manufactories of glass are supplied from the products of 

 similar beds. The conclusion, therefore, that the manufacture of 

 glass on a large scale will soon be introduced in New Zealand is not too 

 hazardous ; at the same time, we may expect that at no distant date, 

 glass sands will be exported in considerable quantities to England and 

 other countries, principally in ships where ballasting is necessary. 



Oees. 

 Having already noticed the occurrence of gold and of some other 

 ores in "Westland, little remains to be said of the presence of metallic 

 riches in Canterbury, the geological features of the latter province 

 unfortunately not being favourable for their presence. However, 

 even the negative evidence is valuable, as it will, or it ought to 

 be, the means of saving the pockets of many colonists who, either 

 guided by incorrect statements of mineral prospectors, or by deceptive 

 appearances, would otherwise invest their money on mining adventures 

 which, as the geological evidence before us proves, must be certain 

 failures. 



