ABSTRACT: Scaly clay is an argillaceous sediment, with a pervasive fabric of lenticular, highly polished, curved, slickensided surfaces and is commonly associated with mélange formations. In regions subject to tropical weathering regimes outcrops of this material erode rapidly giving rise to extensive badlands topography. Islands such as Barbados and Taiwan lose considerable areas of agricultural land to badlands generation each year and associated landslides disrupt settlements and communications.
A programme of laboratory studies has been completed to characterise the physical, mineralogical and mechanical properties of undisturbed samples of these materials. The samples, collected from different depths within weathering profiles, between ground surface and fresh materials with no sign of weathering at depth were each subject to similar experiments. These data illustrate important changes during weathering, including destruction of the original sedimentary structure, a large increase in pore volume and variations in strength.
