Subseafloor weathering of cretaceous basaltic basement revealed by nanomineralogical and conventional clay characterizations

Abstract

Although chemical reactions between basalt and seawater might influence the elemental distribution around the globe, it remains unknown whether or not porous fractions filled with secondary minerals. In this study, clay characterizations were conducted for two basaltic core samples. X-ray diffraction pattern analysis of clay fractions collected from powdered core samples revealed the present of Fe-rich smectite, nontronite, in both samples. By transmission electron microscopy, it was revealed that nontronite was likely formed by weathering.