The shaft at Greenlaws is going downwards at a cracking rate. In
the last couple of weekends we've gone down around 3m. There is little or no
timbering to do, all the sides are stable, and we have now passed the bottom of
the Little Limestone.
Work is concentrated on clearing the chamber
below. The shaft bottomed out on a flat ledge of rock, with galena and fluorite
veins in the ledge. It carries on downwards at a steep angle after stepping
sideways about 2m. We are now digging in shale, the material going up the shaft
consisting of large boulders of vein material, blocks of shale, and sandstone.
At present there is no sign of the limestone level, which is supposed to be
driven in the shale under the limestone. The shale is only 1.8-2.4m thick
according to historical sections. We have cleared a 2m section of it already
with no sign of a level.
It doesn't really matter, if it appears,
great. There might be somewhere to store stuff, or stack rubbish, but there is
just 18m between the bottom of the Little Limestone and the top of the Great
Limestone. We have already cleared a good 2m of this, so have just over 16m to
go before we hit the Great Limestone. From a 2.5m wide vein in the limestone,
it has choked down to about 0.6m wide in the shales, with little ribs of galena
on the footwall.
The shaft is still totally blocked. The material
blocking it is not solid though, much coarser rubble, blocks, with a lot of
cavities. I'm sure the back wall of shale has slipped into it, but there's only
about 1.8m of shale before the sandstone and there is no sign of the horribly
contorted, slumped shales we have seen before so it looks like the shaft is a
bit more stable, partly due to being more vertical. Hopefully digging will get
a bit easier, although I seem to be spending a lot of time with a hammer and
chisel breaking up blocks now.
I'm sure, over the last 2 years, there
have been times when we have privately thought that the Great Limestone was
just a dream.... it's not any more, it is rapidly approaching. My only
reservation is just how wide the vein is in the limestone, and how much of it
is collapsed. We'll have to see.
Last weekend was a Herculean session;
Ross finally made it back up, and barrowed solidly. Nathan and Mick did their
usual, Ian cursed and swore at such a rate that the kibbles ran faster, Les
actually made it down the bottom and worked with me.
Report by Pete.