66 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



with a candlelike flame and showing little tendency to cake. The 

 descriptions by Cox and Denniston make clear that the basins were 

 contemporaneous but not connected. 



The district of Canterbury, embracing the middle eastern part 

 of the island, was examined by Haast.^^ The Malvern Hills area, 

 about 30 miles west from Christchurch and embracing not far from 

 180 square miles, exhibits his Great Brown Coal Formation, which, 

 in the Table of Formations of 1879, is placed at base of the Cre- 

 taceo-Tertiary. The coal seams are numerous, usually thin and 

 always variable. Occasionally, nodules of retinite are numerous. 

 The intervening rocks show great irregularity in structure. Sand- 

 stones have abundance of tree trunks, whose thick bark has been 

 replaced with clay ironstone, while the interior tissue has been re- 

 placed with " woodstone " or filled with black shaly material. 



The extensive district of Otago, embracing the southern part of 

 the island, was examined by Haast, McKay and Hutton.-^ In 

 Haast's area the lower part of the column has near the base a mass 

 composed of subangular fragments of schists and containing irregu- 

 lar seams of coal, 6 to 15 inches thick. Higher up, the rock be- 

 comes a conglomerate with well-rounded pebbles of quartz. The 

 thin-bedded sandstones and shales following this conglomerate have 

 only thin seams, but in the upper part of the column there are beds 

 of conglomerate separated by thinner shales and sandstones, which 

 hold important coal seams. 



Coals are mined on Green Island. Near one of the shafts, 

 McKay saw a bed of fossilized roots " sticking in an old soil, just 

 as they grew." At another locality, a workable coal seam under- 

 lies beds containing Bclcmnitella. 



According to Hutton, the area of Cretaceous coals is small in 

 Otago. The most important field is near Shag River, where there 

 are at least 6 workable seams, yielding the best of brown coal. The 

 seams are thin in the Mount Hamilton field, rarely exceeding 10 

 inches, but the coal is bituminous. The highest sandstone there con- 

 tains at base an angular block of sandstone, 8 by 3 feet, resting on 



19 J. Haast, N. Z. Geol. Reps, for 1871-2, pp. 1-88. 



20 J. Haast, Reps, for 1871-2, pp. 14S-153; A. McKay, Reps, for 1873-4, 

 pp. 59, 60; F. Hutton, "Geology of Otago," Dunedin, 1875, pp. 44, ioa-103. 



