Geology.—The county presents a remarkable simplicity of geological structure. Its surface is controlled throughout by the “Hercynian” folds, running from the Kerry border eastward to the sea at Youghal. The Old Red Sandstone comes out in the north, forming the heather-clad Ballyhoura Hills, which are repeated across the limestone hollow of Mitchelstown by the western spur of the Knockmealdown Mountains. On the west, beds as high as the Millstone Grit and Coal Measures remain above the limestone, extending from Mallow and Kanturk to the Limerick and Kerry borders. Another synclinal of Carboniferous Limestone runs from Millstreet through Lismore, and the Blackwater has worn out an easy course along it. Then the Old Red Sandstone again rises as an undulating upland through the centre of the county, with a few synclinal patches of Carboniferous Shale and Limestone caught in on its back. Cork city lies on the north slope and in the floor of a larger synclinal, and the Yellow Sandstone, which forms the passage-beds from the Old Red Sandstone to the Carboniferous, appears near the city. This hollow continues across the Lee through Middleton. The limestone in it has become crystalline, veined and brecciated, while a fine red staining, especially at Little Island, adds to its value as a marble. After another anticlinal of Old Red Sandstone, the Carboniferous Slate occupies most of the country southward, with occasional appearances of the basal Coomhola Grits and of the underlying Old Red Sandstone along anticlinals. The soils thus vary from sandy loams, usually on the higher ground, to stiff clays along the limestone hollows.
This country admirably illustrates the system of river-development originally traced out by Prof. J. B. Jukes in 1862, and further explained by Prof. W. M. Davis and others. The folded series, culminating originally in Upper Carboniferous strata, was worn down, perhaps as far back as Permian times, until it possessed a fairly uniform surface. This surface, or “peneplain,” was probably the result of denudation working away the beds almost to sea-level. A subsequent elevation enabled the streams, as in so many cases now recognized, to cut into the surface along the direction of greatest inclination, which here happened to be southward. When the higher strata had been worn away, the rivers and their tributaries worked upon rocks of very various hardness, but with a common strike from east to west. The tributaries, running along the strike, speedily confined themselves to the synclinals of limestone, along which they could erode and dissolve long valleys. The present surface of anticlinal sandstone ridges and synclinal limestone hollows thus began to arise; but the main streams still held on their courses across the strike, that is, from north to south. Here and there a more active tributary worked its way back at its head into the basin of one of the cross-streams, and drew off into its own system the head-waters of this other stream. With this new flood of water the strengthened system still further deepened its original ravine across the strike, while the beheaded cross-stream or streams rapidly dwindled in importance. Ultimately, the tributaries of the surviving river-systems appeared as the most important feature, stretching far west—in the case of county Cork—along the synclinal hollows; while the original cross-ravine remained in the course of each river, a right-angled bend occurring thus in the lower portion of the valleys. Jukes urged that the upper part of the original cross-ravine can be traced above the bend in each case, though the stream now descending along it seems merely a tributary entering parallel with the north-and-south portion of the main stream. Moreover, the tributaries on the north side of the great synclinal valleys may in many cases be the relics of original cross-streams that once flowed directly to the sea until captured by the growth along the synclinal of the tributary of another stream. The Blackwater, rising on Upper Carboniferous beds on the Kerry border, thus falls steeply southward to Rathmore, and then turns eastward along the synclinal valley of limestone from Millstreet to Cappoquin. Here it abruptly turns south, keeping, in fact, to that part of its valley which was first developed. The Lee, rising in the Old Red Sandstone moors of Gouganebarra, runs east, encountering one or two patches of limestone in the floor of the synclinal on its way, mere residues of the rock that once occupied the hollow. Near Cork, the limestone and accompanying shale are better preserved; but the river, instead of continuing along the synclinal through Middleton to Youghal, turns south, and forms the now submerged valley of Cork Harbour. Observations have shown that the coast lay much at its present level in pre-Glacial times, and that Cork Harbour was thus a marine inlet before the ice descended into it. The synclinal valleys of Bantry Bay and Dunmanus Bay were also, in all probability, submerged at this same early epoch.
The county has been famous for its copper-mines, notably at Allihies in the extreme west. The region south-west of Bantry has been mined in several places. Both gold and silver have been found in the copper-ores of this latter area. Barytes has been mined near Bantry, Schull and Clonakilty, and manganese-ore at Glandore. Anthracite has been raised from time to time in the band of Coal Measures south-west of Kanturk. The marble of Little Island near Cork is quarried under the name of “Cork Red,” and the veined pink and grey marble of Middleton is also much esteemed.
Climate and Watering-places.—The climate is moist and warm, the prevailing winds being from the west and south-west. The annual rainfall in the city of Cork is about 40 in., that of the whole county being somewhat higher. The mean annual temperature is about 52° F. The snow-fall during the winter is usually slight, and snow rarely remains long on the ground except in sheltered places. The thermal spring of Mallow was formerly in considerable repute; it is situated in a basin on the banks of the Blackwater, rising from the base of a limestone hill. The chief places for sea-bathing are Blackrock, Passage, Monkstown, Queenstown, and other waterside villages in the vicinity of Cork; Bantry, Baltimore, Kinsale, Glengarrif and Youghal are also much frequented during the summer months.
Industries.—The soils of the county exhibit no great variety. They may be reduced in number to four: the calcareous in the limestone districts; the deep mellow loams found in districts remote from limestone, and generally occurring in the less elevated parts of the grey and red sandstone districts; the light shallow soils, and the moorland or peat soils, the usual substratum of which is coarse retentive clay. About one-sixth of the total area is quite barren. In a district of such extent and variety of surface, the state of agriculture must be liable to much variation. The more populous parts near the sea, and in the vicinity of the great lines of communication, exhibit favourable instances of agricultural improvement. Oats, potatoes and turnips are the principal crops, but the extent of land under tillage shows a general decrease. Pasture land, however, extends, and the number of cattle, sheep and poultry rises; for dairies are numerous and the character of the Cork butter and farmyard produce stands high in English and foreign markets.
Youghal, Kinsale, Queenstown, Castletown and Bearhaven are the deep-sea and coast fishing district centres of the county; while the salmon fishing is distributed among the districts of Cork, Bandon, Skibbereen and Bantry. The mackerel fishery is especially productive from mid-March to mid-June. The Blackwater, Lee and Bandon, apart from the netting industry, afford good rod-fishing for salmon, especially the first, on which Lismore, Fermoy and Mallow are the principal centres. The loughs, the upper waters of these rivers and their tributaries, frequently abound in trout. Macroom, Inchigeelagh, Bandon, Dunmanway and Glandore, with Bantry and Skibbereen, are all good stations.
Communications.—The main line of the Great Southern & Western railway, entering the county from the north at Charleville, serves Cork and Queenstown. The Cork, Bandon & South Coast line runs west to Skibbereen, Baltimore, Bantry, Clonakilty and Kinsale; and there are also the Cork & Macroom line to Macroom; the Cork, Blackrock & Passage to the western waterside villages of Cork Harbour, and the Great Southern & Western branch eastward from Cork to Youghal; while from Mallow a branch of the same system continues towards Killarney and the south-western coast of Ireland. There is also connexion from this junction with Fermoy, Mitchelstown and county Waterford eastward. The Timoleague and Courtmacsherry line connects these villages with the Clonakilty branch of the Cork, Bandon & South Coast Railway.
Population.—The population (438,432 in 1891; 404,611 in 1901) exhibits a decrease among the most serious of the Irish counties, and emigration is correspondingly heavy. Of the total about 90% are Roman Catholics, and about 70% constitute the rural population. The principal towns are Cork (pop. 76,122, a county of a city); Queenstown (7909), Fermoy (6126); Kinsale (4250), Bandon (2830), Youghal (5393), Mallow (4542), Skibbereen (3208), Macroom (3016), Bantry (3109), Middleton (3361), Clonakilty (3098), and among smaller towns Charleville, Mitchelstown, Passage West, Doneraile and Kanturk. Crookhaven in the extreme S.W. is of importance as a harbour of refuge, but the chief ports are Cork and Queenstown. The county is divided into east and west ridings, and contains twenty-three baronies and 249 parishes. Assizes are held at Cork, and quarter-sessions at Cork, Fermoy, Kanturk, Kinsale, Mallow, Middleton, and Youghal in the east riding; and Bandon, Bantry, Clonakilty, Macroom and Skibbereen in the west riding. The county is in the Protestant diocese of Cork, and the Roman Catholic diocese
