Figure 2From: The significance of hydrothermal alteration zones for the mechanical behavior of a geothermal reservoirCore pictures of different facies of the Soultz granite. (a) Fresh granite without evidence of hydrothermal alteration. (b) Pervasive alteration with mainly formation of hematite and no structural influence. (c) Vein alteration with dissolution of silicates and precipitation of clay minerals.Back to article page