This rock from the flanks of Carrock Fell is an Ordovician mudstone called the Drygill Formation. I knew that there was said to be part of the Windermere Supergroup rock formation in these parts but I thought that they were Silurian rocks. In my mind, the Ordovician is volcanic. However this article explains all. It sounds like the volcanoes subsided and a sea formed on top. These mudstones are the first product. We didn't find any fossils. Here is the BGS lexicon description of the rock. This rock is quite bleached but I think that it seems more likely to be due to weathering than due to the intrusion just below.
