On the lower flanks of the cone, the rocks are mostly palagonite bombs from fire-fountaining that preceded the filling of the crater with lava.
12.
Palagonite soil is a light yellow-orange dust, comprising a mixture of particles ranging down to sub-micrometer sizes, usually found mixed with larger fragments of lava.
13.
On top of these volcanic layers are sedimentary materials, sometimes of great thickness, formed mainly of sand, pebbles, and large blocks of rolled palagonite with abundant cavities.
14.
The products of Surtseyan eruptions are generally oxidized palagonite basalts ( though andesitic eruptions do occur, albeit rarely ), and like Strombolian eruptions Surtseyan eruptions are generally continuous or otherwise rhythmic.
15.
The internal structure of this volcano, which is in height above sea level ( at Pico das Cruzinhas ), is marked by layers of basaltic pyroclasts of various thicknesses ( between centimetres and metres thick ) forming a lithificated palagonite tuff.
