Published online by Cambridge University Press: 09 July 2018
X-ray analyses of argillaceous rocks from the Skipton anticline show that their average composition is quartz 30%, calcite 27%, feldspar 5%, illite 15%, kaolin 17%. Pyrite and other constituents account for the remaining 6 %. The quartz, calcite and feldspar are considered to be detrital, the variations in their quantity and size reflecting changes in the source of the sediments. The evidence indicates the general predominance of kaolin over illite, which is contrary to other published results on Carboniferous marine shales. A kaolin-rich source is necessary to account for the composition of the sediments. An occurrence of unusually pure and well-crystalline melanterite is recorded from the Draughton Limestone.