Collective works

“ The northern coast of Antrim seems to have been originally a compact body of limestone, (chalk) considerably higher than the present level of the sea; over which, at some later period, extensive bodies of vitrifiable stone have been superinduced in a state of softness. The original calcareous stratum appears to be very much deranged and interrupted by these incumbent masses. In some places it is depressed greatly below its ancient level. ”

“ The numerous beds of coarse calcareous oolites, which in England succeed this green sandstone, are entirely wanting in Ireland, and the mulattoe reposes immediately on the lias limestone. Analogous circumstances are not however wanting in England. In the neighbourhood of Lyme Regis, in Dorsetshire, the sandstone has extended itself over the cut goings of the oolites, rests upon the lias in a manner similar to that just described; and as it is covered with beds of chalk, the whole section affords an exact counterpart to that presented by the Irish series. ”

“ In a valley near Ballintoy, the inferior limit of the chalk is exposed, and a substratum of a bluish slate clay, containing gryphites and ammonites, (apparently the same which alternates with the lias near Glenarm) is laid open. The chalk is abruptly broken off on the east of White Park bay, in a little cove called Port Braddin. Here the basalt abuts directly against the chalk, and that arrangement of strata, so well known as constituting the magnificent range of promontories in the neighbourhood of the Giant's Causeway, commences. ”

“ These cliffs exhibit basalt towards the summit, and chalk in their central regions; the beds on which the chalk reposes are concealed along the base of the promontory by enormous masses of the superior strata, which have subsided in this direction and form a range of advanced terraces, causing the headland when viewed at a small distance, to appear as if composed of four strata alternately chalk and basalt. Those who have visited the southern coast of the Isle of Wight will on seeing Gerron point be strongly reminded of the similar subsidence there distinguished by the name of the under-cliff. ”

“ In the eastern part of Tyrone which intervenes between these two systems of mountainous ground, a coal formation occurs associated with that variety of limestone which is usually found underlying or alternating with the coal measures in Great Britain.
The position of this coal field offers a new analogy with Scotland, where the interval between the southern and northern mountains is principally occupied by a broad zone of rocks connected with the coal formation, upon which are placed those vast overlying masses of trap formation which constitute the Campsie hill, the Ochills, &c. ”

“ Towards the west the chalk runs far out to sea, forming a sharp and narrow point of land, of which the greatest height is about 70 feet. The isthmus which joins this point with the main land, is completely broken through. The ruins of an ancient tower rise above this chasm, on the sides of which the course of an enormous whin dyke may be traced; and the whole promontory is shattered in every direction, masses of basalt (sometimes mingled with chalky debris and flints) protruding through numerous fissures. ”

“ The N.E. coast presents a small coal formation precisely analogous to that of Ballycastle, with beds of breccia and of red sandstone resembling those which occur in the Antrim coast near New own Glens; this sandstone forms the prevailing substratum through the whole south of the island, where it is covered by a singular columnar clay porphyry, and by greenstone, both of which rocks are generally referred to the flœtz trap series. ”

“ Augite usually accompanies greenstone and sometimes greystone. Steatite is almost exclusively limited to the prismatic basalt; and it is likewise the only heterogeneous ingredient I have observed in it. It exists in small round specks, of a bottle-green colour so dark, that it is not easily discernible from the mass itself: it has a dull and waxy appearance; is soft, the streak greyish.
Glassy felspar characterizes the clinkstone porphyry. Calcareous spar, zeolite, iron pyrites, and chalcedony usually occur in association with the preceding substances. ”

“ Richardson to consider the agent which has acted in the manner described, as some unknown and undiscoverable cause, and to hesitate in receiving the common and surely probable opinion which regards diluvial currents as presenting a satisfactory solution; but it must be remembered that the solitary instances he adduces can never weigh against the great majority of cases in which the fragments of the rocks so destroyed not only occur in abundance where they might be expected, but exhibit the most unequivocal marks of their having experienced the action of agitated waters. ”

“ The cliffs of Cushleak ranging from the mouth of the Glendun river to Murloch bay present mica slate, containing subordinate beds of primitive limestone, syenite, and felspar porphyry.
The hills rising above these cliffs, as they approach Murloch bay, become covered with beds of red sandstone and chalk towards their summits, and some of the highest points exhibit caps of basalt. It is highly desirable that the slopes of these hills should be carefully explored ”

“ It is impossible for any two portions of the same formation to be more entirely identified, by every external character and by the fossils and organic remains contained in them, than are these Irish beds, which have been frequently called white limestone, with the English chalk in the above places: there as in England the lowest beds are destitute of flints which the upper contain in abundance. ”

“ In Carintogher and Cragnashoack the chalk appears to be wanting, and the basalt to repose immediately on the sandstone; but in the insulated mass of secondary strata which cap the primitive mass of Slieve Gallion (on the south of the great valley of denudation, through which the Mayola flows) the chalk again appears underneath the basalt, and there attains its greatest elevation, being quarried at the considerable height of 1460 feet above the level of the sea, the deposit is however thin and the strata much split. ”

“ The solid strata are frequently traversed by veins and thin layers of calcareous spar: between them intervene many thinner beds passing into slaty marl.
The limestone itself somewhat varies in its characters at the different places where it occurs. In point of colour it passes from bluish-black to smoke-grey: the first variety is more compact, the lamellar concretions less evident, and it is sometimes traversed by veins of flinty slate; small quartz concretions are occasionally though rarely interspersed in it. I have seen in it crystallized iron pyrites ”

“ A little to the north-east of the source of the Roe, and almost surrounded by the secondary and basaltic ridges of Benbradagh and Cragnashoack, we are surprised at meeting with a small insulated district of mica slate; it forms the entire mass of the mountain of Coolcoscrahan, which rises nearly 1300 feet above the level of the sea. ”

“ The pillars of Fairhead, and the adjacent summit of Fairhead, are composed of greenstone containing augite.
Basalt passes into greenstone in the most imperceptible manner: in the first stage, the felspar exists under the form of short, scaly parts either white or greenish; the texture becomes more finely granular and crystalline; the fracture in the great is not into flat conchoidal pieces, but more usually into irregular and blunted fragments. This finely granular and almost compact greenstone is also more tough than common flœtz-trap. ”

“ Near Ballycastle a broad valley opens into the interior towards wards the south and east. This valley is principally occupied by the red sandstone, which, in those directions terminates against the mica slate, forming the base of Knocklead (the round-backed mountain seen in the distance) and extending thus far in continuation of the primitive district already described in Cushleak. Between 4 and 500 feet on the ascent of this mountain, a bed of primitive limestone may be traced. Above this, through an interval of about 400 feet, the strata have not been ascertained ”

“ Mulattoe, an arenaceous stone, with a calcareous cement, of a speckled appearance (whence its name) derived from numerous disseminated spots of green earth. It agrees altogether in its character and fossils with the green sandstone, which occurs in a similar geological position underlying the chalk in England: the thickness of this deposit appears to vary very considerably, and has not in any instance been precisely ascertained. ”

“ The greenstone slate of the Mourne mountains contains apparently no crystallized hornblende in the basis, though it is disseminated through the latter, as is shewn by the manner in which it fuses before the blowpipe. I have remarked in it some crystals of glassy actynolite passing into hornblende, veins of quartz, magnetic and common iron pyrites. The basis sometimes approaches in its nature to clay-slate. ”

“ From Blackhead the eastern coast of the peninsula of Magee exhibits a long and lofty range of basaltic cliffs called the Gobbins, extending nearly eight miles towards Portmuck at the north-east extremity of the peninsula; near this point the chalk emerges from beneath the basalt, and the lias from beneath the chalk. Hence to the mouth of Lame tough the cliffs cease, the hills rising with a gradual acclivity from the beach ”

“ I. Tyrone: at Coal-island and Dungannon. II. Antrim: near Ballycastle. 1. Two Coal fields, as coal formations are usually styled in England, exist in the county of Tyrone, at no great distance the one from the other, viz. at Coal island and Dungannon; with the latter I am totally unacquainted: it is I believe, by far the most extensive of the two: whether they may be considered as connected and thus constituting but one single formation, I do not pretend to say.
The coal formation of Coal island is in an open part of the country, though with a gently waved surface. ”

“ Owing to prejudice, I believe, rather than to greater expence, the country people prefer burning turf rather than coals, and even the inhabitants of the Isle of Rathlin, who have but a very spare quantity of that combustible, come to the Main to carry it over instead of coals, though ultimately it must be more expensive and surely more troublesome. ”

“ The peninsula itself, which may be about a mile in circumference, is fenced with low cliffs on the west, north, and east; those on the west present a rudely prismatic greenstone; those on the north and east tabular masses of greenstone, overlying, and in some places appearing to alternate with, a very remarkable rock which has been the subject of much discussion among the supporters of opposite theories.
It is a flinty slate, exactly similar to the indurated slate clay which forms the wall of the Carrick Mawr dyke, in the Ballycastle collieries ”

“ The sandstone formation may be traced from the south west extremity of the county of Antrim, where it joins that of Down, occurring between Moira and Lisburn, at Maherameslt, Spencer's bridge and Maheragall; it proceeds along the valley of the Lagan, extending into that of the Forth, a small river which becomes tributary to the Lagan near Belfast; from that town it occupies the road to Carrickfergus, whence it ascends the valley of the Woodburn, another brook discharging itself into Belfast Lough; it afterwards extends as far as Castle Chichester, in the island of Magee. ”

“ At the point of Taur in Antrim, the colour of the limestone varies from grey to reddish grey, and greenish grey; the concretions are rather large, and the texture passes sometimes from granular into compact; it contains only a small quantity of magnetic iron pyrites.
The strata are alternately coarsely and finely slaty: the thickness of the whole mass may be rated at fifty feet. Veins of calcareous spar intervene as seams between the individual strata. ”

“ Where the dyke traverses the great insulated mass of slate, it is very irregular both in thickness and direction. The works of Gob colliery have reached, this dyke 500 yards inland from the face of the cliff: the coal is altered by it to a considerable distance from its point of contact, being reduced to the state of a cinder, which can be employed only for burning lime. ”

“ In the Mourne mountains and adjoining districts an extensive formation of granite occurs, but neither here nor elsewhere in the north of Ireland can we recognize the same varieties of that rock which the mountains of Wicklow present. ”

“ The slate clay at Mary Ann Pit contains impressions of aquatic plants, vegetable impressions similar to those of the Derbyshire collieries have also been observed in the Ballycastle district.
Clay ironstone occurs both in nodules and beds, and brown spar passing into sparry iron ore has been observed at the coal works of Ballycastle, where it forms a bed of some thickness traversing the cliff at a little depth below the principal seam of coal. ”