| Only andesitic tuffs have phenocrysts, amygdaloidal structures, and slight flow structures. |
| The various types of medium depth aquifers include massive basalt, amygdaloidal basalt, trachyte, pyroclastics and tuffs. |
| These crystals occur in amygdaloidal cavities, either as massive fillings or as linings of trapezohedral crystals that rarely exceed 1 cm across. |
| The amygdaloidal masses, contained in the amygdaloid, are either entirely pistacite, or pistacite enclosing calc-spar. |
| I ascended one, and found it was capped with trap rock in amygdaloidal nodules. |
| In the northern parts of the Thane Creek amygdaloidal basalt occurs as the medium depth aquifer. |
