
The QAPF diagram, by which a monzonite is defined.
'Monzonite' is an intermediate
igneous intrusive rock composed of approximately equal amounts of sodic to intermediate
plagioclase and
orthoclase feldspars with minor amounts of
hornblende,
biotite and other minerals.
Quartz a minor constituent or is absent; with greater than 10% quartz the rock is termed a
quartz monzonite.
If the rock has more orthoclase or potassium feldspar it grades into a
syenite. With an increase of calcic plagioclase and
mafic minerals the rock type becomes a
diorite. The
volcanic equivalent is the
latite.
See also
★
QAPF diagram