Developments in sedimentology. Volume 15. The chemistry of clay minerals / Исследования в седиментологии. Том 15. Химия глинистых минералов

Clay minerals occur in all types of sediments and sedimentary rocks and are a common constituent of hydrothermal deposits. They are the most abundant minerals in sedimentary rocks perhaps comprising as much as 40% of the minerals in these rocks. Half or more of the clay minerals in the earth's crust are illites, followed, in order of relative abundance, by montmorillonite and mixed-layer illite-montmorillonite, chlorite and mixed-layer chlorite-montmorillonite, kaolinite and septachlorite, attapulgite and sepiolite. The clay minerals are fine-grained. They are built up of tetrahedrally (Si, A l , Fe3+) and octahedrally (Al, Fe3+, Fez+, Mg) coordinated cations organized to form either sheets or chains. All are hydrous. <...>