304 



Tra/i-sarf/ons. 



The coals of the eastern Oweka field are more elevated than those in the 

 central section, and the upper beds of the measures have been removed. 

 Thus the coals are superior to those of the central portion, which in turn 

 grade from sub -bituminous on the east to brown coals on the west. lu the 

 Greymouth field the central elevated ridge carries semi-anthracites to bitu- 

 minous, the degree of carbonization decreasing towards the south as the 

 elevation decreases. South of the Tyneside the coals will probably be 

 sub-bituminous, as are those of Blackball and Point Elizabeth. In the 

 latter place mudstones and limestone overlie the coal. Similarly, in the 

 Westport field the coals of the Mount Rochfort plateau decrease in car- 

 bonization toward the north, where they will be overlaid in depth by mud- 

 stones and become sub -bituminous or brown coals. The seams of the 

 coastal section are likely also to be brown coals, while those of the Orikaka 

 section will grade from sub-bituminous to bituminous according to local 

 conditions. The anthracites of Fox's River, which may be included in 

 the coastal section, are probably of purely local occurrence. Only brown 

 coals have hitherto been reported from the Karamea field, but it seems 

 feasible to suppose that bituminous coals may occur on some elevated ledge. 

 From the above considerations, and from the analyses shown in Table C, 

 the following table may be prepared : — 



Field. 



Section. 



Analyses. 



Quality of Coal. 



Not even the roughest estimate of the quantity of coal available in 

 west Nelson can be given. This is due in part to lack of data, but prin- 

 cipally to the irregular distribution of the seams or lenses of coal throughout 

 the measures and the rapidity with which the thickness of the seams vary. 

 At Denniston only one-tenth of the area of coal-measures contains Avork- 

 able coal. There is, however, little doubt but that many liundreds of 



