The weather was better in May for our visit to Askrigg to see Mill Gill Force, and Ballowfields Nature Reserve for the Carperby Basin. At Mill Gill we walked up through the cyclothem to the Hardraw Limestone at the top. Cyclothems are alternating stratigraphic sequences of marine and non-marine sediments. Different sedimentary rocks are stacked on top of one another in recognizable patterns. There are repetitions of the cycle: limestone – shale – siltstone – sandstone – seat-earth – coal. Coal is taken to define the point at which the sequence is repeated. There are eleven cyclothems in the Yoredale Series. The walk begins on the Gayle Limestone and takes one up through the second cyclothem to the Hardraw Limestone at the top.
Mill Gill Force at Askrigg, Wensleydale. Photo: Jim Hutchinson
In the afternoon we met at Ballowfields Nature Reserve below Haw Bank on the Carperby Road 3 miles east of Askrigg. We took the path up by Eller Beck past the waterfall examining the fossils in the Middle Limestone as we went along. Up on the moor this path meets the Oxclose Road, an ancient track way, and walking east brought our group to the Carperby Basin. This is a much faulted area and has been described as ‘unique within the Yorkshire Dales’. This is the main mining area on the moor, worked for lead, then reworked for fluorspar, used as a flux in the steel making industry.The Knott below Ivy Scar is thought to be an ancient landslip from the time of the faulting, and is now riddled with workings.
