Opal Digging Diary 02 - Black Flag
Marking off prospector shafts for safety
Today, I spent a bit of time marking where all the prospector drill shafts (that I could find) are on my claim at Black Flag. This is to help avoid getting a wheel stuck in driving around at night or worse still, getting a leg caught in one, which can cause a nasty broken bone! As a nearby miner reminded me, I shouldn't get a false sense of security from these, as there may be more shafts buried under a little bit of soil which could still pose a danger, will tread carefully until the surface has been cleared more!
Walking the 50 x 50 meter claim, I found 11 of these foot-wide holes, used by someone before me to get an idea of where the opal level might be. I'm still very green to opal mining and Coober Pedy, but slowly learning how to read the ground and try to figure out what's happened somewhere in recent times or over the millions of years since the opal was formed. With these holes, I haven't had a good look yet or measured the depth, but did note that not all of them had any of the drilled sample material sitting next to the hole. One hole, looked to have the remains of two distinct piles, where the drill may have featured the ability to classify the rock away from the finer material. They are all belled out a bit at the top and not a neat circle, so maybe this gives some tips as to the age of the shafts? I'll check with experienced miner friends next chat. I'll also get around to putting a weight on a bit of rope and gauging the depth of each hole for more information.
Each hole had a waist-height stake driven in, wrapped in bright flagging tape and sprayed a few white rings around the wood. I had limited stakes on me, so placed one at the same cardinal direction of each shaft. I'll revisit and likely place at least 3 on each hole for more safety. I'm expecting that at some point, I'll want to dig where a few of the stakes are, just to have less material I need to manually dig to get another trench in. For now, though, I'm digging away from any of these shafts, gambling that they didn't find big amounts of opal in the sampled material and so didn't drill any bigger shafts or open cut the area. I've heard enough stories of bad luck, such as miners drilling shafts and missing a seam of opal by inches, so maybe that'll be my luck and I'll find what they didn't with their shafts!
I had some help from Grace today, so while I was driving the stakes in, she started clearing the area where we'll extend the trench.
Not a lot more depth or width added to the trench today, but had a little poke around in the harder material with the crowbar and looking forward to having a good session with that and clearing a nice even rectangle down the first layer of hard material in the next session or two.
View from the other side, where we've just cleared a bit of ground where the trench will extend out to in first phase. Continuing to drag material off to the sides and flatten out at this point, as I learned from previous hand trenching that if it's piled too close to the edges, it quickly gets too high to keep throwing material out of the bottom with a shovel. I'm thinking that by alternating between shoveling out and spreading out, I can get away with just a shovel for longer, then switch to a Yorke hoist or some kind of bucket, rope and pulley system on a swing arm to get the material out as I go deeper. Trench collapse as I go deeper is definitely a risk I'll be aware of and adapting things as I go based on depth and stability of the material, likely widening as I go and benching off higher bits.
Making the most of July's cool weather
Today was great, cool and cloudy. Not totally free from flies, but barely any to notice. July should be another cool month, so will want to get as much done before the typical Coober Pedy heat returns and I'm more likely to just dig earlier in the morning.
