Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 and 325 million years ago. Within England and Wales, the entire limestone succession, which includes subordinate mudstones and some thin sandstones, is known as the Carboniferous Limestone Supergroup.
Within Great Britain the suite of rocks known traditionally as the Carboniferous Limestone Series was deposited as marine sediments in three distinct ‘provinces’ separated by contemporary landmasses. One of these landmasses was the Wales-London-Brabant Massif, an east–west aligned belt of land stretching through central Wales and the English Midlands to East Anglia and on into Belgium. The limestones deposited to its south form a distinct South Wales-Mendip province which extends from Pembrokeshire in the west through southern Carmarthenshire, Glamorgan and south Powys to Monmouthshire, Gloucestershire and north Somerset. These rocks continue eastwards at depth beneath Oxfordshire. The Carboniferous Limestone sequence of South Wales and the Bristol area is currently (2012) subdivided thus:
Pembroke Limestone Group (uppermost/youngest)
Oystermouth Formation
Oxwich Head Limestone Formation
Penderyn Oolite Member
Honeycombed Sandstone Member
Dowlais Limestone Formation
Abercriban Oolite Subgroup & Clydach Valley Subgroup
Avon Group
Cwmyniscoy Mudstone Formation
Castell Coch Limestone Formation (lowermost/oldest)
The limestone found north of the Wales-London-Brabant Massif and south of the emergent Southern Uplands block is identified as a separate northern province. It is characterised by the presence of numerous ‘blocks’ and ‘basins’ each with its own particular depositional style.
To the north of the Southern Uplands are the limestones of the Scottish Midland Valley stretching from Ayrshire and Arran in the west to Fife, Lothian and Berwickshire in the east.
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
Les collines de Mendip, en anglais Mendip Hills, communément appelées The Mendips, sont situées dans le Somerset, en Angleterre, au sud-ouest des villes de Bristol et de Bath. Elles culminent à d'altitude à Black Down. Principalement constituées de calcaire, avec du grès et des roches volcaniques, elles présentent un relief karstique prononcé, avec un plateau sommital où s'enfonce un important réseau souterrain, des versants entrecoupés de gorges et des piémonts où ressurgissent les cours d'eau.
Clevedon est une ville et une paroisse civile dans l'autorité unitaire du North Somerset, qui fait partie du comté cérémonial du Somerset, en Angleterre. Entre 1974 et 1996, elle était dans le comté d'Avon. La ville compte près de . Clevedon est située au milieu d'un ensemble de petites collines, le long de l'estuaire de la Severn. Mentionnée dans le Domesday Book au Moyen Âge, Clevedon ne s'est vraiment développée qu'à partir de l'époque victorienne lorsqu'elle est devenue une importante station balnéaire.
Flat Holm (Ynys Echni) is a Welsh island lying in the Bristol Channel approximately from Lavernock Point in the Vale of Glamorgan. It includes the most southerly point of Wales. The island has a long history of occupation, dating at least from the Bronze Age. Religious uses include visits by disciples of Saint Cadoc in the 5th-6th century AD, and in 1835 it was the site of the foundation of the Bristol Channel Mission, which later became the Mission to Seafarers.