Geology helping drilling ahead

We’ve passed another milestone on our journey to the centre of the earth beneath the Eden Project – on Monday we drilled past the 2000m MD mark! As of 6am today, we’ve drilled to 2293m MD.

The higher ROP (rate of penetration) achieved recently is due to the geology we’ve encountered: we’ve been able to drill faster because the rock has been softer. Cuttings have shown higher alteration and kaolin content in the granite. Kaolin (or China clay) is associated with granite alteration and is much softer than competent granite.

This sample was taken at 2100m MD. It is very red/pink in colour due to the high percentage of altered pink feldspar, iron oxide staining and the presence of hematite. We can also see chlorite and accessory mineral tourmaline. Thanks to our wellsite geologist friends at GeoScience for this week’s update.