sinbadsgold
Your question concerning KXL's discovery and gpt versus other gold decoveries that are establised deeper is beyond my knowledge. re your question: "Is this normal and does it tend to go back the other way as we get deeper?"
I have a friend that used to be the senior mining geologist for Santa Fe Gold in Nevada which I will pose your question to. The last I heard from him he was in Australia. I am heading up to Reno for my daughters master's graduation ceremonies at UNR in a few days and will try contacting the geologist who happens to live in Reno, too.