328 



floor, and occasionally in both. In quality the seams vary 

 from where they are entirely composed of clean, bright 

 coal, with about 5 per cent ash, to where they are entirely 

 composed of a dirty slickensided coal, locally called 

 "rash," with over 50 per cent ash. The following is a 

 proximate analysis of the rash from the Wellington seam. 



Proximate Analysis by Fast Coking. 



Water 1-59 



Vol. combust 2 4-i5 



Fixed carbon 19 29 



Ash 54-97 



Sulphur undet . 



The Wellington seam rests on a firm sandstone floor, 

 which is fairly regular although a few sharp rolls do occur 

 in it. The roof, however, varies greatly in character from 

 sandy shale to conglomerate, with many irregularities, 

 especially in the sandy shale. The average thickness of the 

 seam is from 4 to 7 feet (1 to 2 m.), but it occasionally 

 pinches to virtually nothing, and then suddenly thickens 

 to 10 or 12 feet (3 or 4 m.) . The floor may be nearly smooth, 

 but the roof in passing from the thin to the thick portion 

 of the seam rolls upward sharply and often irregularly. 

 Occasionally the roof is overturned forming in one instance 

 an overlap in the seam of at least 25 feet (8 m.). These 

 sharp rolls are locally called "faults." Invariably at 

 the thin places or "pinches" the coal is dirty and slicken- 

 sided, while in the thick places or "swells" it is clean, 

 black in colour with a sub-brilliant lustre, and broken only 

 by a few irregular joints. Rash is usually found near the 

 top and bottom of the swells and rarely in thin partings 

 near the centre. Even in the swells some bone is present 

 as small lenses seldom more than a quarter of an inch thick. 

 In some instances the coal is clean and unfractured against 

 the upturned roof, but more commonly it is somewhat 

 slickensided and even contorted. The roof at the rolls is 

 always contorted and slickensided. 



The strike of the rolls corresponds with the strike of 

 the measures, that is, northwest to west, and the pinches 

 occur in the northeast and north side of the rolls with the 

 corresponding swells on the opposite side. Where the 



