0 a type of grey, light stone that is used in pieces or as a powder for rubbing things to make them smooth -- 浮石，轻石（用来摩擦物体使其光滑）
Pumice is produced in volcanic eruptions. 浮石是在火山爆发中产生的。
Concentrations of pumice clasts towards the base form trains of clasts that are traceable along the length of outcrops.
Concentrations of accretionary lapilli and diffuse trains of small pumices define bedding in this thick ash bed.
For selected ignimbrites, sanidine crystals were taken from fresh, unaltered pumice lapilli.
Due to incomplete exposures, the dispersal characteristics of most pumice fallout deposits are poorly constrained.
Widely dispersed plinian-type pumice fall deposits and ignimbrite are characteristic products of both explosive cycles.
Lithic- and pumice-rich horizons may mark separate eruptive events.
The presence of banded pumice near the top defines a compositional zonation of the ignimbrite.
These tuffs are all considered to be ash flow deposits because they are unbedded and contain well-developed eutaxitic foliation and pumice pseudomorphs locally.
