NEWCASTLE COAL REGION. 473 
In this section we have, 
Grit, : - - - - - 15 feet. 
Coal (I.), - - - - - - 3 feet. 
Argillaceous and arenaceous layers, - - 58 feet. 
Coal (II.), - - - - - - 53 feet. 
Argillaceous and arenaceous, : - - 29 feet. 
Coal (III.), - - - - - - 6. feet. 
Argillaceous and arenaceous, : : - 21 feet. 
Coal (IV.), - - - - - - 6 feet. 
Argillaceous sandstone, - - - - A2 feet. 
Coal (V.), - : - - - - a tect, 
We have been thus particular in noting down the alternations of rock 
in the cliff, especially the upper part of it, in order to give some idea 
of its varying character: and this peculiarity is farther evident from 
the fact that a section a few rods to the right or left is quite different 
in its minor layers. The argillaceous and sandy layers often coalesce, 
or subdivide and change in character, even at short intervals. ‘The 
sandstone is generally quite soft and crumbling, though harder in the 
lower layers. The ironstone beds increase below, and become quite 
numerous ; yet they seldom exceed four inches in thickness, though 
extending laterally to ten or twenty feet, or as many yards; they 
either lie between the layers of bluish sandstone, or are imbedded in 
the middle of them. 
The clayey layers, near the coal beds, are remarkable for their soft- 
ness. When first laid open, the clay may be kneaded in the hands ; 
and after a short exposure, it crumbles into small fragments, showing 
commonly no schistose structure, unless in consequence of imbedded 
vegetable impressions. ‘They more resemble recent deposits of clay 
than the usual argillaceous shales of the carboniferous era. The soft 
character of all the rocks distinguishes them from those of most other 
coal regions; and were we hastily to judge from this character alone, 
we might place these formations high in the geological series. 
The several layers of coal are similar in all the cliffs through the 
half mile examined, excepting a difference in the proportion of clear 
coal and clayey layers. The uppermost bed of coal is an extraordi- 
nary exception to this remark. The layer, without varying in thick- 
ness, gradually changes, a few hundred feet to the northward, to a 
layer of dark-brown clay, coloured with carbonaceous matter, and 
with no pure coal included; two hundred feet from where the above 
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