-
pyroclastic fall
deposits and in ignimbrites,
which are the
deposits of
pumiceous pyroclastic density currents. The name
fiamme comes from the
Italian word...
- It is a grey or cream-coloured
fragmental rock,
largely composed of
pumiceous dust, and may be
regarded as a
trachytic tuff. It much
resembles the Italian...
-
pyroclastic deposit is an ignimbrite,
which is the
deposit of a ground-hugging
pumiceous pyroclastic density current (a
rapidly flowing hot
suspension of pyroclasts...
- have a wide
distribution in
location and age.
Rhyolite tuffs contain pumiceous, gl****y
fragments and
small scoriae with quartz,
alkali feldspar, biotite...
- BCE as part of the
Smith Cr****
eruptive period. The
tephra consists of
pumiceous dacite. "St. Helens".
Global Volcanism Program.
Smithsonian Institution...
- north-facing
crater and
consisted of
glowing pumice bombs and very hot
pumiceous ash. Some of
these hot
flows covered ice or water,
which flashed to steam...
- pulverulence,
pulverulent pumex pumic-
pumice stone pumicate, pumice,
pumiceous, pumiciform,
pumicite pupa pup- doll pupae, pupal, puparium, pupation...
- Rhine). Gl****y
forms of
trachyte (obsidian) occur, as in Iceland, and
pumiceous varieties are
known (in
Tenerife and elsewhere), but
these rocks as contrasted...
- due to
ductile elongation in the
volcanic conduit or, in the case of
pumiceous lavas,
during flow. The
other form of
vesicles are
subspherical to spherical...
-
consists of breccia, tuff, and
flows of
rhyolite and
dacite overlain by
pumiceous strata. The Plio-Pleistocene Mba
Grouop is
found on the
southwestern portion...
