Origin, mineralogical behaviour and spatial distribution of 2/1 clay minerals in a ferrallitic soil cover on volcanic parent rock of Guadeloupe

Ferrallitic soils in Guadeloupe, covering the older part of the island of Basse Terre, are derived from andesitic pyroclastic deposits. These often heavy textured clay soils are mainly composed of 1 :1 lattice clay minerals with a halloysitic character. Recently, the local occurence of minor amounts of 2 :1 clays has been reported, showing different degrees of alteration. The aim of this paper is to consider several hypotheses about the origin and the spatial distribution of these 2 :1 clay minerals. Their mineralogical characteristics are studied by X-ray diffraction and ТЕМ. Since the degree of alteration of the 2 :1 minerals is closely related to physico-chemical soil behaviour, understanding their spatial distribution is essential to improve agronomic management.van Oort Folkert, Jaunet Anne-Marie. Origin, mineralogical behaviour and spatial distribution of 2/1 clay minerals in a ferrallitic soil cover on volcanic parent rock of Guadeloupe. In: Proceedings of the 9th international Clay Conference, Strasbourg, 1989. Vol I : Clay-organic interactions. Clay minerals in soils. Strasbourg : Institut de Géologie – Université Louis-Pasteur, 1990. pp. 205-213. (Sciences Géologiques. Mémoire, 85