Geology Reference
In-Depth Information
(a)
(b)
(c)
(d)
(e)
(f)
Figure 9.2
(a) Classic magma mingling showing 'pillows' of microdiorite with
chilled margins intruded into pink granophyre, Jersey, Channel Islands. (b) Fine-
scale dendritic structures in mafic enclaves resulting from 'viscous fingering'
(disruption of mafic fluid within a non-Newtonian granitic host), Maine, USA.
(c) Detail of cuspate (fluid-fluid contacts) typical of magma mingling in the
field. Cusps generally point towards the magma with the lowest viscosity,
Jersey, Channel Islands. (d) Magma mixing and hybridisation zone between
diorite and co-mingling pink granophyre, Jersey, Channel Islands. (e) Fine-scale,
wispy granitic vein cutting angular diorite enclave, Jersey, Channel Islands.
(f) Agmatite - magma 'breccia' of shattered, jigsaw-like mafic enclaves in a
granitic host indicative of magma mingling at high strain-rates, Jersey, Channel
Islands.
