The weight of the wild camping pack made for slow going up a very modest gradient across the moorland, giving me plenty of time to reflect on; my physical conditioning was sub prime; the ascent of the Carneddau would have been an interesting experience; George Monbiot's observations on the environmental destruction by sheep is pretty much on the money; the flowering bog cotton clearly demarcated areas of degrading peat and when stringers of cirrus cloud started streaming across the sky, I'll confess to wondering why I bother. I did stumble upon a delightful camping spot, a raised fairly level pitch on moss covered ground, a nearby stream and a pitch with a wonderful backdrop, things were looking up. With the tent pitched, dinner cooked and heartily eaten, it was time for a wander.
The main viewpoint for sunset was the escarpment of Bannau Sir Gaer with its suite of geomorphological landforms and exposures of sedimentary geology. With a viewpoint found, there was plenty of time until sunset to stand back and contemplate Deep Time. The youngest features visible are the alluvial fans at the foot of gulleys and vivid active debris flows that scar the hill slopes, some geomorphologists speculate that the active debris flows have been initiated due to a change of grazing regime to predominantly sheep grazing around 1600AD. The next suite of landforms are the talus cones formed from freeze thaw weathering of mudstones/shales and undermining of overlying sandstones'siltstones, and represent periglacial weathering at the end of the last Ice Age, with minor accumulations in the holocene. The scarp foot landforms and the cirque enclosing Llyn y Fan Fach indicate possible permanent snow beds and the presence of glacial ice of the late Devensian stadial. Though there are landforms that appear 'fresh' in appearance and other landforms with an older, less defined features, possibly demarcating landforms formed either side of an interstadial between the Older and Younger Dryas stadials. There's also some intriguing overprinting of landforms, that indicates an event chronology; alluvial fans 'gulleying' and burying the talus deposits; talus deposits infilling depressions and overriding scarp foot landforms and some of the scarp foot ramparts show successive crests or ridges implying retreat/advance of glacial ice/snow patches. Then it's into Deep Time proper, with a gap of some 280-300 million years to the end of the Variscan orogeny and the folding of bedrock into the South Wales syncline. Back another 70 million years to the end of the Devonian, conglomerates were uncomformably deposited onto a strata of the Lower Devonian. The lower Red Devonian sediments originated from a vast mountain chain eroding to the north. A few miles to the north, in the Myddfai Steep Belt, Silurian strata is almost vertical in attitude and striking SW to NE it represent an expression of the Caledonian orogeny and what is now believed to be a terrane boundary, that pushes the geological history back into Proterozoic.
On the walk back to the tent some thought was given to what the Cirrus clouds heralded for dawn.
The resident Sky Lark population woke me before the alarm sounded about 03.00hrs, with the tent being buffeted and an ominous 'booming' noise to the west, suggested the weather wasn't going to play ball. A look outside and the NE horizon seemed promising, alas Y Mynydd Du was blanketed in hill fog, sigh. Plan A was abandoned and other options considered with a cunning photography plan B of an image of flowering bog cotton at sunrise formulated.
Eroding peat hags reveal a land surface that is probably representative of its appearance at the end of the last Ice age, when this area would have been tundra.
The weather then deteriorated rapidly and a damp hill fog blanketed everything, which made for an interesting bit of compass work to find the tent again.
The weather seemed set in, so I 'rested my eyes' for a while and opened them to find the hill fog lifting and cloud breaking up, the best of the light was long gone, but the tent pitch deserved a record shot before breaking camp and heading home.
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