Termau daeareg ydy’r cyd-destun. Dyma’r
diffiniad:
Flow banding is a geological term to describe
bands or layers that can sometimes be seen in rock that formed from the
substance molten rock or magma.
Flow banding is caused by friction of the
viscous magma which is in contact with a solid rock interface, usually the wall
rock to an intrusive chamber or if the magma is erupted, the surface of the
earth across which a lava is
flowing.
The friction and viscosity of the magma causes
phenocrysts and
xenoliths within the magma or lava to slow down near the interface
and become trapped in a viscous layer. This forms laminar flow, which manifests
as a banded, streaky appearance.
A oes term cydnabyddedig os gwelwch yn
dda?