Published online by Cambridge University Press: 14 March 2018
The synthesis of kandites in the granites of south-west England has resulted from the breakdown of albite or oligoclase by hydrothermal solutions using joints and faults as channels. The crystallinity of the clay mineral and the extent of argillization are related to the distance from these channels. Intermediate stages between felspar and kaolinite remain obscure but recent evidence suggests that they may be represented by montmorillonite. Little is known about the composition of hydrothermal solutions: fluorine and boron determinations on rocks in various stages of argillization suggest that neither of these elements was an important constituent.