64 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



taceous, only two forms having been recognized. One of them be- 

 longs to Glossopteris and was found in the Desert Sandstone. Ethe- 

 ridge cannot distinguish it from G. hrozvniana and G. ampla, which 

 abound in the Permo-carboniferous of Queensland and New South 

 Wales. The important coal deposits of New Zealand, in the lower 

 part of the Cretaceo-Tertiary, occupy some extensive areas in the 

 South Island and a less important area in the North Island. The 

 South Island was studied in detail long ago by Hector^*' and his 

 associates. Hector examined Nelson district, the northern part of 

 the island. The coal-bearing rocks at the Collingwood mine, in the 

 extreme north, rest on 105 feet of conglomerate and are 250 feet 

 thick. They are mostly thick-bedded clayey sandstones with inter- 

 bedded carbonaceous shales, which have 6 coal seams, from i to 4 

 feet thick. But the coal is broken badly by partings. On the 

 Ngakawau River there is a seam, 16 feet thick and yielding good 

 caking coal, which burns freely with a sooty flame. In the lower 

 canyon of Buller River, he saw a bed of compact brown coal, at 

 least 16 feet thick, underlying brown micaceous sandstone and over- 

 lying a conglomerate or breccia of great thickness, which has a few 

 thin seams of coal. The thick seam, which has much fossil resin, 

 varies in composition ; samples from different parts of the bed have 

 from 33.45 to 46.85 per cent, of volatile combustible matter in the 

 pure coal. The ash in raw coal is about 7 per cent. A seam, 20 

 feet thick, is mined on a branch of Buller River ; its ash is remark- 

 ably low, varying from 0.98 to 1.19 per cent. The coal in some 

 parts of the seam is compact, with bright luster and splintery frac- 

 ture, but in others it is dull, with fracture like that of brown coal, 

 and resembles jet. 



In the Grey River area, the southwest corner of the district, the 

 basal rocks are conglomerate and breccia, succeeded by 200 to 800 

 feet of sandstones, grits and shales with beds of anhydrous caking 

 coal. Above these is a non-persistent conglomerate. Where this 

 last is absent, the sandstones pass gradually into sandy clays with 

 marine fossils and nodular clay iron-stone. Immediately below 

 these marine beds and resting on the conglomerate or, in its absence, 



^^ J. Hector, "Geological Survey of New Zealand," 1872, pp. 129-141, 

 158-165. 



