AbstractThe Borrowdale Volcanic Rocks of the Seathwaite Fells, northwest of Coniston, Lancashire, consist of up to 13550 ft of lavas and tuffs, mainly andesitic in composition, but including some rhyolitic rocks among which are welded tuffs. They occupy a position in the lower part of the Borrowdale Volcanic succession and dip steeply to the southeast with little folding. A number of northerly trending faults and others with a trend between east‐northeast and east‐southeast traverse the area. Volcanic vents filled with agglomerate have been found at two pla