New page: Pertaining to fragmented (clastic) rock material formed by a volcanic explosion or ejection from a volcanic vent. (Foxworthy and Hill, 1982) <ref>[http://vulcan.wr.usgs.gov/Glossary/volcan...
Pertaining to fragmented (clastic) rock material formed by a volcanic explosion or ejection from a volcanic vent. (Foxworthy and Hill, 1982) <ref>[http://vulcan.wr.usgs.gov/Glossary/volcano_terminology.html Glossary of Volcano and Related Terminology]</ref>