Post-eruption, meltwater derived from the ice cap has caused hydrothermal alteration of the volcano.
22.
A specific type of hydrothermal alteration termed " fenitization " is typically associated with carbonatite intrusions.
23.
Native nickel has been described as serpentinite due to hydrothermal alteration of ultramafic rocks in New Caledonia and elsewhere.
24.
These rocks were subsequently subject to hydrothermal alteration by and rich which in multiple stages formed the mineral veins.
25.
They include the extensive hydrothermal alteration of rhyolites and gabbros and a central megabreccia created by hydrothermal dissolution and collapse.
26.
A collapse amphitheatre is found in these valleys, possibly because the underlying country rock was destabilized by hydrothermal alteration.
27.
Hydrothermal alteration may be driven by the formation of a deep magma reservoir and resulting hydrothermal circulation in overlying rocks.
28.
This hydrothermal alteration of susceptible rocks makes Corrida de Cori's peaks look snow-covered from a distance.
29.
Spilite is formed when basaltic lava reacts with seawater, or from hydrothermal alteration when seawater circulates through hot volcanic rocks.
30.
Like other chlorites, it is a product of the hydrothermal alteration of pyroxenes, amphiboles and biotite in igneous rock.
