Location
The geologically older parts of the two main islands of Great Britain and Ireland, which were only finally separated at the end of the Tertiary, lie in the north and north-west, where west, north and south-east Ireland, the Scottish mountains, the Cumbrian Mountains in north-west England as well as North and Central Wales are the remnants of the Old Paleozoic Caledonian Mountains (Silurian / Devonian) with a southwest-northeast structure. After removal and sedimentation, the Upper Palaeozoic Armorican Arch (Carboniferous / Permian) with a west-east structure was added to the south; it determines the construction of southern Ireland, south Wales and the south-western peninsula of England. The north-south-sweeping bulge of the Pennine Mountains occupies a special position. It consists mainly of layers of carbon on top of older, more folded layers of the Caledonian system. – removal, The Mesozoic era was characterized by subsidence with extensive sea flooding in the Jurassic and Cretaceous periods and the sedimentation of surface layers. The Mesozoic strata (Triassic to Cretaceous) experienced an inclined position in the Alpid era and a slight bulge in the southeast, in the area of the Weald. To the south-east of a line from the Exe to the Tees estuary, a distinctive layered relief has formed in England due to the succession of differently resistant sediments.
During the Ice Age (Pleistocene), according to Franciscogardening, the island of Great Britain remained ice-free in the south, north of a line from the Severn to the Thames estuary, the lowland was glacial overprinted by a layer of boulder clay and the northern mountainous area by glacial erosion forms (trough valleys, cirques, lakes). The coasts of the main island of Great Britain are also very diverse due to changing large reliefs, rock differences, ice age influences (e.g. fjords in the northwest) and post-ice sea level fluctuations. – In Ireland, the central lowland consisting of sub-carbonic limestone, framed on three sides by mountainous lands, was shaped by ice-age deposits (moraines, drumlins, oser), on which extensive raised bogs (Bog of Allen) have developed in addition to soils that are favorable for agriculture. The mountainous regions of Ireland made up of paleozoic rocks, which are strongly structured in the southwest by sea bays (Ria coast) penetrating deep into the interior, received their fine modeling through glacial erosion (cirques, trough valleys, lakes). – The north-west of Ireland is shaped by wide-spread levels with individual quartzite hilltops (Twelve Bens in Connemara) protruding as hardships. Mesozoic layers have largely been eroded, Tertiary is found in the form of extensive basalt layers in Northern Ireland in the Antrim district. – The north-west of Ireland is shaped by wide-spread levels with individual quartzite hilltops (Twelve Bens in Connemara) protruding as hardships. Mesozoic layers have largely been eroded, Tertiary is found in the form of extensive basalt layers in Northern Ireland in the Antrim district. – The north-west of Ireland is shaped by wide-spread levels with individual quartzite hilltops (Twelve Bens in Connemara) protruding as hardships. Mesozoic layers have largely been eroded, Tertiary is found in the form of extensive basalt layers in Northern Ireland in the Antrim district.
The island of Great Britain was only separated from the continent as a result of the post-glacial sea level rise. The course of settlement and economic development since the Stone Age has been influenced by the spatial contrast between High Britain in the west and north (up to 1,085 m above sea level in the Cambrian Mountains of Wales, up to 978 m above sea level in the Cumbrian Mountains of north-west England, up to 1,345 m above sea level in the Highlands of Scotland) and lowland Great Britain in the center and in the south-east. The lowland framing the southern Pennine Mountains and structured by layers is the core area of settlement and economy.
Climate
The climate is distinctly oceanic; it is characterized by mild winters and cool summers in the south and south-east with prevailing westerly winds, fairly even distribution of precipitation over the year with relatively dry spring. The sea water, also warmed in winter by the foothills of the Gulf Stream, has temperatures of 11–14 ° C into autumn. South-west Ireland and the south-west peninsula of England are particularly favorable. Frosts are rare in the lowlands. Snow only stays longer in the higher mountain countries (in Ireland not there either) (on Ben Nevis in Scotland from November to June). The long north-south extension causes temperature differences from south to north and delaying the arrival of spring by six or more weeks between south-west England and the Scottish Highlands. This gradient is crossed by the even stronger east-west gradient in the ocean. 1,000 to 3,000 mm of rain receive the very humid hinterland of the Irish west coast, up to 5,000 mm of precipitation parts of the Scottish Highlands with around 250-270 rainy days per year, compared to 700 mm in Dublin (Eastern Ireland) and only 500 mm in Eastern England, whose climate already shows more continental characteristics. Further characteristics are the increasing duration of sunshine from west to east as well as high humidity, which favors coastal, mountain, meadow and city fog formation. compared to 700 mm in Dublin (Eastern Ireland) and only 500 mm in East England, whose climate already shows more continental characteristics. Further characteristics are the increasing duration of sunshine from west to east as well as high humidity, which favors coastal, mountain, meadow and city fog formation. compared to 700 mm in Dublin (Eastern Ireland) and only 500 mm in East England, whose climate already shows more continental characteristics. Further characteristics are the increasing duration of sunshine from west to east as well as high humidity, which favors coastal, mountain, meadow and city fog formation.
Vegetation
The natural vegetation of the British Isles belongs to the Atlantic district of the European deciduous forest area with marshes (most extensive in the Fens), with raised and lowland moors. Mountain heaths (English moorlands) extend below and above the natural tree line (around 300–600 m above sea level depending on the location), to the expansion of which man has made a significant contribution through the destruction of forests. Blanket bogs, a type of bog that does not occur in Central Europe, cover mountain regions with high levels of precipitation and high humidity. Arctic alpine plant communities occur in the summit regions and in the northernmost locations. Except for relic sites, the natural forest has been destroyed. With parks and coppice, the main island of Great Britain has a forest share of approx. 12%, Ireland around 9%. In connection with considerable reforestation since 1919, foreign conifers in particular were naturalized.
