The boreholes for the PSG experiment were drilled in January 2004. The core material from the injection borehole was found to be completely homogenous matrix to a depth of around 1.3 metres. The cores from the injection borehole are shown below.

Core material from PSG injection borehole - sections shown below in higher resolution

Section 1

Section 2

Section 3

Section 4

Section 5

Sections from the cores were sent to Finland for lab based porosity measurements (see the Support of in-situ test section).

The drilled PSG boreholes in the WT tunnel with the air ventilation system in place