The Sugar Loaf, near Abergavenny
More autumn colour this week, taken a couple of year’s ago at around on a beautiful sunny afternoon. The Sugar Loaf, named for the archaic way sugar used to be sold, is one of the iconic hills of the Black Mountains, indeed of the Brecon Beacons. Recognisable from almost any direction, the striking sugar loaf shape has been used for any number of logos by local businesses.
The steep-sided cone shape has also led many to think that this is an extinct volcano. However, this could not be further from the truth -the geology here is purely sedimentary. To be precise the Sugar Loaf is made up of the Brownstone Group of the Old Red Sandstone, a rock created in a fluvial (river) environment, deposited at a time when the landmass that would become the British Isles was drifting across the tropics. This is topped off by a quartz conglomerate, the resulting from a change in the kinetic energy of those rivers as sea level changed. Slightly harder wearing, these rocks give the hill its distinctive flat top. In fact the granular material that makes up the rock would have been eroded from the Caledonian mountains, freshly formed in the north of the country around 400 million years ago, and carried down that mountain range by the young rivers of the time. For this to become a hill in its own right (sorry, the Sugar Loaf is not quite a mountain, it’s 4m short of that particular classification), further tectonic movement buckled the layers of sand and silt into a great bowl, known in geology as a synclinorium, which brought the sandstone to the surface. (By the way, at its centre, that synclinorium holds the coal measures for which South Wales is famous.) What has followed since then is the action of the Brecon Beacons Ice Cap at the height of the last ice age (around 26k years ago), combined with thousands of years of fluvial erosion, subaerial weathering, and mass movement. It also helps that there’s a major fault line in the valley to the north of the ‘mountain’ called the Neath Disturbance, a natural line of weakness for landforming agents to exploit. It’s that combination of factors that led to the distinctive concave slopes leading down from the summit ridge, not volcanic action in the distant past.
As a hill, the Sugar Loaf provides a great deal of photographic interest, standing separate from the rest of the Black Mountains, and with great viewpoints in almost all directions -I’ve ended up snapping it time and time again. The walk to the top in itself is well worth a visit, with great views across to the central Beacons, the Bristol Channel and the Malvern Hills. Great for sunrise and sunset photos too! Much more to come from the Sugar Loaf in years to come…
As a panoramic, this one’s best at 12″x5″ or 20″x8″.
All images © Stephen Tyrrell, Mountains, Wild Places & Water, 2013. All rights reserved.