After the devastating M w 7.3 Nanbu-Kobe earthquake of 1995, a 750 m deep borehole was drilled to the Nojima fault core at 625 m, less than 1 year after the earthquake. This borehole was drilled at the Hirabayashi site by the GSJ (Geological Survey of Japan).
Continuous coring and borehole logging showed the granodiorite protolith experienced several stages of alteration : (1) a pre-faulting alteration at T>270°C generating pervasive chloritization, (2) a fault-related alteration that (…)

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The Soultz-Sous-Forêtssite was the focus of geothermal energy research in France at the beginning of years 2000 and is still one of the major Enhanced Geothermal Systems (EGS) sites in France.
It is drilled through monzogranitic rocks to 5km. A mineralogic and petrophysical description provides a detailed static description of alteration, mainly related to the deposition of illite, which reduce permeability, and high porosity tosudite, rich in lithium (Li).
The exact phasing of (…)

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