Examination of the weathered rock profile of low grade metapelites in arid Australia illustrates changes due to two different weathering environments. The most significant was a period of high rainfall which resulted in some important changes in mineralogy. The second, and present, climatic condition has resulted in halite, gypsum and carbonates in the near surface. Solution has been effective in increasing porosity, which results in a reduction of strength and elasticity. A tentative engineering classification of weathered metapelites is presented.