![]() Follow this for about 1km until you reach a road with a house to right which is know has the Waterman’s cottage. Turn right and follow the path along the valley south, with the steep hillside of Anglezarke Moor to your left. The meltwater channels in this area including the cited channel to the North in Brinscall, which fed and created the channels now occupied by the Reservoirs, were apparently left dry as the water found a new channel at Withnell Fold a few miles to the west – see Stage 13. As the water drained away, successive channels would be left stranded above the new lake level and therefore the water would have to find a new route to escape. A number of scientists envisaged a serious of lakes being left behind in East Lancashire and the Ribble valley at various heights and these draining via meltwater channels as they escaped to lower and lower heights. In my investigations, there seems to be very little agreement by scientists over the origin of many of the glacial features that we can see in Lancashire. Indeed the glaciers would melt away first from the thinnest parts, which would be along the sides of the valleys adjacent to the ice free uplands to the East. It is very likely that these channels were lateral channels, running along the side of the glacier in the valley and with the moorlands producing a barrier to the east. In addition to this the valleys in which the reservoirs now stand are deep and thin and are thought to be glacial melt water channels ie have been eroded by strong rivers flowing off, under or along the sides of glaciers as they melted and retreated. These are made from sediments deposited from beneath the glacier and shaped by the movement of ice. The hill just behind the white washed cottages on the other side of the pitch is a perfect example of a drumlin. Firstly you can see examples of drumlins, rounded hills, in the valley around White Coppice, which are a very typical feature of a glacial environment. The impact of this faulting and the resultant topology ie the highly erosion resistant Millstone Grit moors to the east, with some resistant bands of sandstones in the Chorley plain, has affected the impact of glaciation upon this area. To understand the juxtaposition of successively younger rocks at lower levels requires extensive faulting in the area, far more extensive than the fault in Dean Brook, dropping successively younger rocks down to the west/north west. Across the valley Healey Nab, which rises to only 200m is made from slightly younger Millstone Grit rocks (Rough Rock – approximately 313m years old) and then further west beyond that are the even younger Coal Measures that underlie most of the town of Chorley. These form the whole of the moorland to the east rising almost 250 meters above us on Great Hill and Black Hill. The moors to east are made up of Millstone Grits or more specifically the Fletcher Grits of the Namurian Stage (315m years old) of the Carboniferous era. However, there are two other geological phenomina, which I think are more impressive. In addition to quarrying the hardwaring gritstones, the faulting gave rise to a small amount of lead mining and even some other minerals. ![]() Head past the pavilion and through the gates over The Goit ie the man made water course which carries water down from more reservoirs further north via Brinscall towards the reservoirs at Rivington.īefore starting the walk there is an information board, which explains a little of the geology of the area and concentrates upon the fault that can be seen in Dean Brook, which comes off the moors almost opposite you.
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