The present study deals with mineralogy, diagenesis and their impact on chemical composition for Early
Paleozoic; Cambro-Ordovician (Adediya and Abu Hamata Formations) and Late Paleozoic; Early Carboniferous (El
Hashash and Magharet El Maiah) mudrocks at South Western Sinai area.
Mineralogical study reveals the presence of kaolinite and illite clay minerals. The detection of kaolinite and illite
clay minerals favour that the environment of formation was alkaline, and the origin of the clay minerals present is
chlorite more probably than illite origin where illite can be derived from weathering of chlorite.
Diagenetic study reveals that; kaolinite can be neo-formed, transformed at high rainfall and a temperate climate
which can transform muscovite and biotite into kaolinite together with some illite.
Chemical composition study; abundance, behavior and distribution of major and trace components reveals that
the studied mudrocks seem to be formed under reducing alkaline environment.