Basaltic lava flows are produced from the extrusion of silica deficient and iron-magnesium rich lava. Basaltic rocks have variable textures and compositions. Scoria is a highly vesicular volcanic material formed by the rapid expansion of gasses during the explosive eruption of lava. It is found in small irregular shaped welded fragments. Scoria has thicker vesicle walls than its counterpart, pumice. It is a widespread volcanic material that can be found in most volcanic terrains, characteristically in cinder cones that are found in clusters along fissure lines. The Kingdom of Saudi Arabia has abundant basaltic lava fields in its western region. There are 12 large lava fields covering an area of about 90,000 km~2. Predominantly black with subordinate red basaltic scoria cones are found associated with volcanic vents. The scoria cones are generally surrounded by basaltic airfall ash. The basalt itself is dense (about 3g/cm~3), however, scoria is lightweight (0.5-1.7g/cm~3) and also has insulating and pozzolanic characters. Some of these occurrences carry semi-precious peridote (olivine).
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