-
accessory minerals. Feldspathoid-bearing
latite is
sometimes referred to as
tristanite.
Rhomb porphyries are an
unusual variety with gray-white
porphyritic rhomb...
- of alkali-basalt
cinder cones and lava
flows with
minor trachyte and
tristanite; the
trachyte stratovolcano of Furnas; and the
Nordeste shield, which...
- lava flows.
Volcanic rocks such as basalt, trachybasalt, benmoreite,
tristanite, mugearite,
trachyte and
rhyolite were
deposited by
multiple eruptions...
-
evolves through trachybasalt or
leucite trachybasalt through tristanite or
leucite tristanite to pot****ic
trachyte or
leucite phonolite. The nephelinic,...
- is more diverse,
consisting of
alkali basalt, hawaiite, trachybasalt,
tristanite, mugearite, benmoreite,
trachyte and
rhyolite which are in the form of...
-
rhyolite and
trachyte domes.
Basalt flows and
smaller amounts of trachyte,
tristanite, trachybasalt,
benmoreite and
mugearite produced during the
second stage...
- The
lower ****emblage
consists of
alkali basalt and
hawaiite with
minor tristanite,
trachybasalt and mugearite.
These rocks are in the form of
pillow lavas...
- Ice Peak Formation. They
consist of trachyte, benmoreite, mugearite,
tristanite,
trachybasalt and
alkali basalt that are in the form of lava flows, lava...
-
intermediate composition such as benmoreite, trachybasalt,
mugearite and
tristanite are
present in
relatively small volumes and are the
result of
alkali basaltic...
- the
Pyramid Formation is
Pleistocene alkali basalt,
hawaiite and
minor tristanite,
trachybasalt and
mugearite of the
lower ****emblage of the Ice Peak Formation...
