-
varieties of
plagioclase feldspar.
Mafic materials can also be
described as
ferromagnesian. The term
mafic is a
portmanteau of "magnesium" and "ferric" and was...
-
Serpentinization is a
hydration and
metamorphic transformation of
ferromagnesian minerals, such as
olivine and pyroxene, in
mafic and
ultramafic rock to...
- anorthosite): the
lower part of the
crust may
contain a
higher percentage of
ferromagnesian minerals such as the
pyroxenes and olivine, but even that
lower part...
-
which will
eventually crystallise a
relatively small proportion of
ferromagnesian silicates, such as amphibole, pyroxene, and biotite. The main constituents...
-
composed of
feldspars sometimes ****ociated with
quartz and
anhydrous ferromagnesian minerals, with
granoblastic texture and
gneissose to m****ive structure...
- Up to half of the rock is
plagioclase feldspar with the rest
being ferromagnesian minerals.
angular unconformity An
unconformity in
which younger strata...
- as
olivine or enstatite, or with
alumina and lime form the
complex ferromagnesian silicates of
which the pyroxenes, amphiboles, and
biotites are the chief...
-
metamorphism (tremolite) and
those formed by the
alteration of
other ferromagnesian minerals (such as
hornblende as an
alteration product of pyroxene)....
- biotite) are formed. The
ferromagnesian minerals are ****umed to be free of Al2O3. The Fe/Mg
ratio for all
ferromagnesian minerals is ****umed to be the...
-
feldspars often are
interleaved as
perthitic components of the rock. When
ferromagnesian minerals are
present in
syenite at all, they
usually occur in the form...