ROCK-MEASURES OF LUGG-GLASS[1] (The Green-Hollow.)
| from below upwards.. | ||||
| provincial terms. | geognostic names | feet. | inch. | |
| 1 | Hard-rock | Sandstone | 33 | |
| 2 | Till | Slate-clay | 2 | 6 |
| 3 | Rock | Sandstone, probably | 33 | |
| 4 | Main Till | Main bed of Slate-clay | 18 | |
| 5 | Coal | Slate Coal | 4 | 6 |
| 6 | Rock | Rock | 33 | |
| Total | 124 | 4 | ||
The preceding tables evince the general resemblance which the members of these coal formations bear to those of other countries. Iris necessary to add very few remarks.
The coal of these districts is almost entirely slate coal; it may perhaps be suggested as a general observation concerning the Irish
- ↑ The above section relates only to the beds contiguous to the coal now worked. Sections of the entire cliff have been given by Mr. Whitehurst in his Theory of the Earth, page 260, and by Mr. Dubordieu in the Statistical Survey of Antrim; but it is impossible to reconcile the one to the other. From the hasty survey which I was myself able to take of this spot, I can only furnish the following particulars:─
The total height of Cross Hill, in the north face of which the collieries are worked, is about 500 feet, of this elevation about 150 feet is formed by a cap of columnar green-stone, which reposes on alternating strata of sandstone and slate-clay, these extend about 150 feet in depth, and cover the bed of coal in which the workings are situated, and which occurs at an elevation of about 200 feet above the beach; below it are other strata of slate-clay, with perhaps some seams of imperfect coal and sandstone, and we particularly observed beds of the latter rock, of an intensely red colour and of enormous thickness: lastly, strata of limestone are seen emerging from the sea towards the west of the collieries; the interval between the coal and the limestone is much concealed by slopes of debris, covered with an imperfect vegetation, which rest against the base of the cliff.
An opinion is prevalent among some of the miners, that a thicker stratum of coal than that at present in working would be found by driving adits beneath the level of the sea.
