Page 378 - Caldera Volcanism Analysis, Modelling and Response

Facilitating Dike Intrusions into Ring-Faults 353

Structural control Little Major

stages, resurgence stages, or formation
Timing Late All before, during, after caldera

to
Composition Mainly evolved magmas kinds, All primitive evolved magmas

dyke an faults
Genetics Forceful intrusion from over- pressurised reservoir also May intrude passively into opening (ring)

dykes. Number Multiple intrusions, sheets Often individual dykes

ring to
and Width cm m m km
sheets Scale to or Scale

cone circular elliptical elliptical, angular, polygonal
into Strike Mainly Circular,
ring-complexes Geometry dip, Inward 30–451 multiple sheets to Vertical outward W901 dip, single often only event

of Dip
Classification Class Cone sheets Ring dykes

1 Domain complex
Table Ring