a small cavity in an aphanitic (fine-grained) or glassy igneous rock, formed by the expansion of a bubble of gas or steam during the solidification of the rock
{i} bladder or bladder-like cavity; small blister filled with fluid; sac in the body, cyst (especially one filled with fluid); cavity formed in a rock by a pocket of gas that is trapped during the rock's formation (Geology)
A circumscribed cavity in the epidermis filled with serum, plasma, or blood and covered by a thin layer of epidermis that is greatly elevated above the surface
A bubble-shaped cavity in lava, formed by the expansion of entrapped gases Such cavities may later become filled with material deposited from solution Vesicular basalt (bubbly basalt lava) is basaltic lava containing numerous openings, generally ellipsoidal or cylindrical in shape, formed by the expansion of dissolved gases in the molten rock