0 a very large, circular hollow that remains when the central part of a volcano falls in after an eruption --
The caldera is partially filled and surrounded by crystal-rich ignimbrite (f).
Many of the major eruptions recorded by the extensive lithic brecciabearing ignimbrite sheets may have involved caldera collapse.
The caldera has chemical characteristics that could result in ambiguous or incorrect tectonic discrimination if the entire rock suite was not considered as a whole.
They have been interpreted to represent part of a caldera-related succession, possibly intra-caldera.
Fractionation was repeatedly interrupted by eruption of material from the roof zone such that seven stages of caldera development have been identified.
This igneous activity was focused on the southwest margin of the dormant caldera.
This northern caldera was formed in the 21 000 year explosive eruption.
It is possible that this embayment is a caldera or lateral collapse structure.
