This type of trigger is very useful for three purposes:

The internal wall of the active crater is very weak due to hydrothermal changes in the volcano.

The duration, intensity and causes of this wildly different past surface environment remain poorly constrained, as do the processes involved (hydrothermal and supergene alteration), and how this primitive environment evolved.

The Kiimalaki, Kellolaki and Kiimakuusikko prospects have been identified within the domain of strongly sheared and hydrothermally altered rocks in the northern portion of the Hanhimaa Shear Zone.

It looks to be the result of a large hydrothermal system.

Halloysite typically forms by hydrothermal alteration of alumino-silicate minerals.

Days 5 and 6: Fluid-rock Interaction and Processes of Hydrothermal Alteration

Hydrothermal alteration has been identified in, or near, about half the domes.

$ SEG UQAM – Quantifying Hydrothermal Alteration: Theoretical and Practical Tools (workshop given in English and French)

These two major shear and hydrothermal alteration zones cross the property in a roughly east-west direction.

We target a series of minerals that could be formed from the hydrothermal alteration of peridotites, komatiites, basalts and gabbros.

The colors in the canyon are the result of hydrothermal alteration in the various iron compounds in the rock.

Hydrothermal alteration produces mineralogical replacements involving a complete reorganization of both the matrix skeleton and the pore network.