|A sample of cemented cataclasite is carefully extracted from the core catcher|
Coring progressed smoothly this time, even though one of our drillers walked out on us for no apparent reason. For the last two days I have been working as a drillers offsider, trying to keep us on track with the project, but it has been tough to balance every demand.A sample of cemented cataclasite is carefully extracted from the core catcher.
Drama continued again last night when a sudden storm passed through at 2-4 a.m., flattening our core processing and logging facility. Fortunately, nothing catastrophic was lost or damaged.We rebuilt better and were ready to drill again by 7 a.m.
|Cores of the Alpine Fault footwall emerge for the first time|
At about 7 p.m. we collected the first core from beneath the problem zone (thanks to the skill of our driller on the levers, “Egor”). This core and the subsequent two confirmed that we had just crossed the principal slip surface of the Alpine Fault at a depth of 128 m. Fantastic!
Both of our boreholes have obtained high-quality cores across the fault, including the precious fault gouge of the primary fault surface. There is a clear sense of excitement and achievement, and a big group has decided to work through the night to see what is going to appear.The rock cores currently emerging are really interesting, because the rock types immediately beneath the fault are not well known, in comparison to the well exposed and studied sequence above.
|A beautiful core of the Alpine Fault from 128 m|
It is premature for me to say what the rocks are that we cored, but brilliant white and green shades indicated that we had crossed the fault. We decided to keep going for another shift, and over the next 24 hours a preliminary geological description will be constructed.
If all goes to plan, we will have finished our main phase of drilling tomorrow. We will move onto
wireline logging and geophysical observatory installation. I personally now need a few hours
sleep after the drama of the previous two nights.
|John Townend, Richard Norris, Rupert Sutherland, and Virginia Toy consider achievement so far|