These flows are generally less than a metre thick and mostly basaltic with scoriaceous inclusions. Tezontle is a well-cemented, agglomeritic and scoriaceous rock. Some of the flows are still so young as to preserve their scoriaceous surface. It is the remains of scoriaceous lava flows, breccias, volcanic bombs and . The Devil's Peak Member consists of scoriaceous andesitic and dacitic flows. Aside from these lapilli deposits, scoriaceous lava flows are exposed on the edifice as well.