-
Ultramafic rocks (also
referred to as
ultrabasic rocks,
although the
terms are not
wholly equivalent) are
igneous and meta-igneous
rocks with a very low...
- analcite, prehnite, natrolite, scolecite, chabazite, heulandite, etc.
Ultramafic tuffs are
extremely rare;
their characteristic is the
abundance of olivine...
- on the Mohs
scale of 5.5.
Chromite minerals are
mainly found in mafic-
ultramafic igneous intrusions and are also
sometimes found in
metamorphic rocks....
- melt. Ideally, the
stratigraphic sequence of an
ultramafic-mafic
intrusive complex consists of
ultramafic peridotites and
pyroxenites with ****ociated chromitite...
-
volcanic rock Blairmorite – Rare
porphyritic volcanic rock Boninite –
Ultramafic extrusive rock high in both
magnesium and
silica Carbonatite – Igneous...
-
chemical types based on
silica content: felsic, intermediate, mafic, and
ultramafic.
Felsic or
silicic lavas have a
silica content greater than 63%. They...
- ****ociations are noted: high-alumina basalts, ultrapot****ic
igneous rocks, and
ultramafic rocks. The
basaltic occurrence of
phlogopite is in ****ociation with picrite...
-
which stretch along ****stan, India, Nepal, and Bhutan. Talc
carbonate ultramafics are
typical of many
areas of the
Archaean cratons,
notably the komatiite...
-
consisting mostly of the
silicate minerals olivine and pyroxene.
Peridotite is
ultramafic, as the rock
contains less than 45% silica. It is high in
magnesium (Mg2+)...
-
dioxide is such a
common component of
metamorphic fluids, talc-carbonated
ultramafics are
relatively common. However, the
degree of talc-carbonation is usually...
