According to Ethnicityology, the British territory has a very ancient formation, since it largely dates back to the primary or Paleozoic era (this is also the reason for the country’s mineral wealth). All ‘ Caledonian orogeny, which is widely expressed in the Silurian and Devonian, should the findings of the northern and western sections of the island: the Highlands in Scotland, divided by the tectonic depression of Glen Mor (or Great Glen) in the Northwest Highlands and in the Southeast Highlands (which have the main range in the Grampians), and the Southern Uplands; in Wales the Cambrian Mountains. These reliefs represent the continuation of the Scandinavian system, as also shown by the orientation from NE to SW, well underlined by Glen Mor; the reliefs of Northern Ireland also date back to the Caledonian orogeny. The reliefs of England are due to the subsequent (Upper Paleozoic) Hercynian orogeny, which rise in the central (Pennini mountains) and southwestern (Cornish heights) part of the island and which connect with the Armorican ones of north-western France.
The erosive activity demolished the ancient British reliefs; the most depressed parts, for example the London Basin, which remained submerged for a long time, were filled with marine sediments (limestone) from the Mesozoic, especially in the Jurassic and Cretaceous, and sandstone of the Cenozoic; as a repercussion of the Alpine orogeny there were further settlements accompanied by fractures through which volcanic materials escaped that still emerge in Northern Ireland and in the Hebrides islands, near the northwestern coast of Scotland. During the Neozoic there was a great expansion of glaciers, whose very marked action is due to the trough valleys with steep sides and wide bottoms often occupied by lakes (famous is the Lake District, in the Cumberland massif), the fjords, particularly pronounced in the northwestern coast, and the moraine hills (drumlins), very pronounced in Ireland. With the retreat of the ice, the eustatic movements caused a marine entry into the territory, with the consequent division of the island from the continent, between which the English Channel, no more than 200 m deep, interposed. The country has an extraordinary correspondence between geological structure and aspects of the landscape. Predominantly mountainous (Highland Britain) is Paleozoic Britain, while flat (Lowland Britain) is Mesozoic and Cenozoic Britain. But also in Highland Britain the antiquity of the relief, long smoothed and worn out by the intense glacial action, is manifested by low and generally rounded shapes (in Scotland, however, there are often asperities), typical of a mature if not senile morphology; the highest elevation, the Scottish Ben Nevis, barely reaches 1343m, while in Wales Mount Snowdon (Cambrian Mountains) reaches 1085m and in England Scafell Pike (Cumberland Mountains) is only 978m. They characterize Lowland Britain flat sections or slight undulations, with mainly tabular structures; the overlapping of the sedimentary layers is evident, for example, along the coasts of the English Channel: the white hues of the Mesozoic marly stratifications, very marked in Dover, gave the island the ancient name of Albion (probably “white earth”).
The vast postglacial marine ingress is also partly responsible for the extremely complex articulations of the British coasts which, given the poverty of the floodplains, are mostly high and rocky. The Scottish coasts are particularly indented, thickly carved by the firths, narrow gulfs that penetrate right into the heart of the region (spectacular the Moray Firth and the Firth of Forth, on the eastern side, the Firth of Lorne and the Firth of Clyde on the western one), which often correspond to river mouths. The English coasts, which are also very articulated, are high and rocky on the Atlantic side (where they are interrupted by the Welsh peninsula, widely swept into the Bay of Cardigan): there are the deep recesses of the Bay of Liverpool and the Bristol Channel, refuge of those magnificent ports that have played so much in Britain’s seafaring fortunes. Generally low and sandy are the southern English coasts (which at the southwestern end however extend with the rocky and jagged Cornwall) and eastern; on the southeast side is the Thames estuary, gateway to the most important and vital part of the country. Finally, the northeastern coast of Northern Ireland is steep, where the Antrim mountains reach the sea, while elsewhere it is mostly low with wide crescents. Of the three great British regions, the largest is England, largely facing the Channel to the S, the North Sea to the E, while to the West it is partly limited by Wales, between the two maritime “openings” of the Atlantic Ocean and the Irish Sea. The region, which has a rugged landscape only in the north-western extremity (Cumberland mountains), is crossed in the central-western area by the lowest and sweetest chain of the Pennines,and, to the SW, the Cornish heights (Dartmoor, 621m); in the large eastern and south-eastern stretch, on the other hand, a series of slightly undulating plains extends (the Midlands, the London Basin, the Fens, etc.). A very marked furrow, consisting of the Dee and Severn valleys, divides England from Wales, a squat mountainous peninsula largely occupied by the Cambrian Mountains and overlooking the Atlantic (Bristol Channel), the St George’s Channel and the Sea of Ireland. A well-marked bottleneck to the W from the Solway Firth instead separates England from Scotland. The region, also eminently mountainous, is largely occupied by the Highlands, which show impressive traces of the glaciation everywhere.Quaternary, and from the lower and sweetest Uplands; the two massifs are divided by a deep depression (the Lowlands) at which the island narrows, between the Firth of Clyde and the Firth of Forth, just 50 km away. Finally, Northern Ireland appears as a vast basin, partly occupied in the center by Lough Neagh and surrounded by the Caledonian reliefs that large river valleys separate, so as to make them isolated groups.