18 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



The Ipswich or newer formation occupies an area of about 

 12,000 square miles in southeastern Queensland and consists, for 

 the most part, of fine conglomerates, grits, sandstones and shales 

 with seams of coal and beds of fireclay. At a few miles south from 

 Brisbane, W. H. Rands saw a mass of coal and carbonaceous shale, 

 12 to 13 feet thick. The "best" coal is in the lower portion; some 

 pieces of hard bright coal, free from shale partings, contained 24 

 per cent, of ash. A seam in the same neighborhood shows (i) coal, 

 4 inches; (2) shale, 2 feet, 2 inches; (3) coal with bands of shale, 

 I foot, 6 inches; (4) good, hard coal, 5 feet, 3 inches; (5) shale, 3 

 inches; (6) fireclay, 2 inches; (7) shale with bands of coal, 5 feet, 

 6 inches; (8) fireclay, i foot, 4 inches; (9) coal, 2 feet; (10) black 

 band, 8 inches; (11) coal, 5 feet, 3 inches; (12) hard sandstone, 2 

 inches; (13) coal, 4 inches; in all, 24 feet, 11 inches with somewhat 

 more than 14 feet of coal aside from the thin bands of coal in the thick 

 shale division. A piece from No. 11 had 19 per cent, of ash. A shaft 

 in this district cut one foot of cannel and, lower down, a seam of hard 

 and bright bituminous coal, but the sample from it contained 31.61 

 per cent, of ash. The coals in this district are much broken by 

 partings and high in ash ; yet, there were times and places during 

 and in which conditions favoring accumulation of clean coal ex- 

 isted ; for a piece taken from a thin bench at one locality showed 

 only 2.5 per cent, of ash. 



The type district, that of Ipswich, about 30 miles west from 

 Brisbane, was examined by A. C. Gregory. The best seam near 

 Ipswich is 5 feet, 6 inches thick and contains 3 to 4 feet of coal, of 

 which the best contains about 1 1 per cent, of ash. Beyond Brisbane 

 River, the seams contain comparatively little coal and that is usually 

 poor ; but one of them becomes 4 feet, 6 inches at one locality and its 

 coal has barely 9 per cent, of ash. This seam, however, deteriorates 

 in all directions. This variability characterizes seams throughout 

 the district ; a thin seam may be disseminated in a mass of coaly shale, 

 20 to 30 feet thick. Gregory ascertained that the quality of coal 

 bears some relation to its distance from the northern margin of the 

 field, the ash increasing in that direction — that is, toward the border 

 of the great valley in which the coal measures accumulated. 



