-
Exceptionally old
obsidians include a
Cretaceous welded tuff and a
partially devitrified Ordovician perlite. This
transformation of
obsidian is
accelerated by...
-
calcium bentonite. In
stratigraphy and tephrochronology,
completely devitrified (weathered
volcanic gl****) ash-fall beds are
commonly referred to as...
-
temperature just
insufficient to
cause fusion. In this way, the crystalline,
devitrified material,
known as Réaumur's gl****
porcelain is produced.
Although generally...
- Yoshiokaite, a
mineral formed as
shocked crystal fragments in
devitrified gl****, was
discovered in
lunar regolith breccia collected from a
trench by the...
-
processes in
igneous rocks. It is
called 'graphic'
because the
exsolved or
devitrified minerals form
lines and
shapes which are
reminiscent of writing. Graphic...
-
found to be
entirely composed of gl****. Typically, they are
completely devitrified into a very fine-grained
material with
quench textures such as chilled...
-
variable amounts of
olivine and
augite in a gl****y matrix; the gl**** may be
devitrified. It was
originally described and
named by J. W.
Gregory in 1900 for the...
-
bentonite is more common. In
stratigraphy and tephrochronology,
completely devitrified (weathered
volcanic gl****) ash-fall beds are
sometimes also referred...
- stratification. ****ulate; see also
layered intrusion Decussate Devitirification;
devitrified Dendritic texture;
dendrites Diatextite; see also
schlieren and migmatite...
- they are
surrounded by a gl****y or
felsitic base. When
obsidians are
devitrified, the
spherulites are
often traceable,
though they may be more or less...
