Pyroclastic rock Reference Libraries
Volcanic ash is the term for very fine rock and mineral particles less than 2 mm in diameter that are ejected from a volcanic vent. Ash is created when solid rock shatters and magma separates into minute particles during explosive volcanic activity. The usually violent nature of an eruption involving steam (phreatic eruption) results in the magma and perhaps solid rock surrounding the vent,...
- Like a worm in form or movement; vermiform; tortuous or sinuous; also, writhing or wriggling.
- Like the track or trace of a worm; appearing as if worm-eaten; vermiculate.
- Marked with fine, close-set, wavy or tortuous lines of color; vermiculated.
- A form of rusticated masonry which is so wrought as to appear thickly indented with worm-tracks.