We encountered some limestone bedrock that would not yield, even with our 345 excavator.
A substantial amount of values were still in these natural riffles we encountered. You can see the bedrock very clearly here and how it show's nature doing its best to concentrate the gold.
Its a nice example of a sedimentary process and response. This depositional setting and bedrock change, for the short term really helped our bottom line at the end of the day.
As we advanced further, the bedrock was softer and we were back on our normal recovery values.
You always try to recognize changes as you encounter them and adjust your materials handling to the new challenge! Gold placer mining is an ever evolving process.
