Abstract
The mineralogical and chemical properties of Tertiary limestones and a soil profile formed on Tertiary limestone were studied. Palygorskite or smectite dominated the silicate mineralogy of the limestone, but no clear relationship could be established between palygorskite and dolomite or total carbonate contents. Hard limestones contained more palygorskite and less smectite than marly limestone. Thus the mode of crystallization of the limestone may be a factor in palygorskite formation, as is the chemical composition of the formation environment. Cristobalite and zeolite were present in the clay fraction of some limestones, especially the marly limestone with high smectite content. Soil formed on one of the limestones contained more smectite and less palygorskite in the topsoil than the subsoil, indicating that smectite may have formed from palygorskite as a result of weathering. (Authors' abstract)