Published online by Cambridge University Press: 01 May 2009
Wall rocks on either side of narrow fluorite veins cutting Dinantian Limestones at Butts Quarry, Derbyshire, exhibit unusual and spectacular alteration structures. Buff, ‘blackened’ and grey limestone lithologies, containing significant amounts of euhedral quartz crystals, occur in a zoned sequence adjacent to the veins. The alteration structures are attributed to a two-stage process involving silicification and subsequent re-mobilization of silica by fluids passing along the vein.