Etude par diffraction des minéraux argileux de vases méditerranéenes

Samples obtained from the sea bottom in the vicinity of the islands of Capri and Sardinia have shown the following mineral composition of their clay fraction : illite, chlorite, kaolinite, and montmorillonite in a mixed-layer assemblage. These determinations have been made by X-ray diffraction. Quantitative estimates and pétrographic examinations show that the montmorillonite is of volcanic origin and is altered to produce mixed-layer structures. The alteration continues with the formation of illite from the mixed-layers. No variation in the abundance of kaolinite has been observed. The alterations mentioned above are functions of the thickness of the sediments