| Abstract: | Several products of weathering have been studied in a granitic outcrop in Galicia (N.W. Spain). Alteration took place under a humid temperate climate. The various materials and the microsystems in which they occur are: (1) fissures containing gibbsite and/or 1:1 sheet silicates of varying degrees of crystallinity, (2) fissures containing 2:1 sheet silicates of beidellite type, (3) encrustations of siliceous material showing varying degrees of structural order, with or without organic matter, and (4) encrustations of non-crystalline matter composed chiefly of Al, P and Si.The results demonstrate the importance of considering the different microsystems which contribute to the formation of secondary products in a given weathering system. |
