Уэльстің Карнеддау таулары

Mountain group in Wales

The Carneddau (lit. 'the cairns'; Carneddau is a Welsh plural form, and is sometimes anglicised to Carnedds) are a group of mountains in Snowdonia, Wales. They include the largest contiguous areas of high ground (over 2500 feet (762 m) or 3000 feet (914 m) high) in Wales and England (although larger areas over 2000 feet (610 m) are found in Northern England), as well as six or seven of the highest peaks in the country—the Fifteen Peaks. The range also encloses a number of lakes such as Llyn Cowlyd and Llyn Eigiau, and the Aber Falls waterfall. It is delimited by the Irish Sea to the north, the Conwy valley to the east, and by the A5 road from Betws y Coed to Bethesda to the south and west. The area covers nearly , about 10% of the area of Snowdonia. The area is bordered by three main roads—the A55 (to the north), the A5 to the south and the A470 to the east.

In common with much of Snowdonia, the rocks forming the Carneddau originated largely during the Ordovician period between 485 and 444 Ma (million years ago). Principal among these are the mudstones and sandstones of the Arenig (478 470 Ma) to Caradoc age (459 449 Ma) Nant Ffrancon Subgroup and the tuffs etc. of the Caradoc age Llewelyn Volcanic Group. These are overlain by the sandstones, siltstones, tuffs and tuffites of the Cwm Eigiau Formation. Within the Nant Ffrancon sequence are a variety of igneous intrusions and the lavas and tuffs of the Foel Fras Volcanic Complex. The complex geology results from the plate tectonic processes taking place during the Caledonian orogeny involving continental landmasses on either side of the Iapetus Ocean moving together and colliding over a protracted period. Over time, these mountains have been eroded by the weather and scoured by advancing and retreating ice sheets. The Carneddau were formed in this way and consist of volcanic and sedimentary rock. The last ice sheet retreated about 10,000 years ago. It left behind a landscape of smooth summits above erratic boulders and scree at the foot of cliffs on the eastern side of the mountains, and moraines that created shallow lakes in the cwms. On the north western slopes of Drosgl there are clusters of Iron Age huts and three cairns were built on the top of Moel Faban. This settlement endured for a thousand years, lasting until after the Romans arrived. There are other huts elsewhere and traces of field systems and numerous hill forts situated at strategic upland sites. The Romans subdued the area and built a road, Bwlch y Ddeufaen across the northern slopes of the Carneddau. After they left in 410, the land was controlled once again by Welsh princes who schemed and formed alliances among themselves. The clearance of the native forests continued and at one time goats were the main form of livestock. Their feral descendants are still found in the area today on the Glyderau. They were later followed by cattle and it was not till the 18th century desire for wool that sheep became numerous. By the thirteenth century, English ambitions were increasing under King Edward I of England in this part of Wales and the English castles encircled Snowdonia.

The plants growing on the Carneddau need to be extremely hardy to withstand the snow, frosts, and gales they will encounter during the year and those found by sheltered streams in the valleys are very different from those clinging to crevices on windswept rocks. Sheep graze the mountains and impact the composition of the sward, nibbling out the most succulent young growth. Where the sheep are fenced out globe flowers, wood avens, angelica, red campion and roseroot can be found at lower elevations, along with ash, alder, hawthorn, holly and rowan. Higher up on scree there are Welsh poppies and in damp crevices under rocks the rare Wilson's filmy fern. Boggy areas support cotton grass, marsh orchid, sundew and bog asphodel. The better drained rocky slopes have bilberry, ling, bell heather and cross leaved heath and the summit ridge has prostrate dwarf willows, sedges, mosses and lichens. Numbers were severely reduced by the heavy snows of spring 2013.