As I explained, you can but it is less likely to be useful. If you get your eye in, you will find three dumps around a deep lead shaft. The mullock dump, consisting of rock the shaft passed through. This is often almost all basalt with so little gravel it is of little use (being a deep and therefore large mine, they usually had an efficient way of removing gravel from the shaft vicinity when it got to surface - less so with shallow leads where stuff got spilled and wasted or dumped next to the shaft if it was considered low grade). Second is the pebble dump - the pebbles screened out during washing - no gold except very large nuggets they missed because it has been through a sieve (so not very useful). Thirdly. a lower dump that was originally the slums dam, now consisting of sand (originally this had a wall around it, now rotted away, so it now looks like a low dump). This has had the gold washed out of it. I would not detect deep leads.
Hope that clarifies....
