Agoracom

That makes sense regarding Bonanza Hills. I'm surprised that Millrock thought there could be disseminated gold, because the results from prior drilling looked like a vein gold system to me. The good news therefore is that Milrock didn't give up due to not finding further vein gold.

My understanding is that you get either vein systems or disseminated, but not - or at least very rarely - both together. Originally vein gold was the only type that was mined. Disseminated is essentially invisible to the naked eye; the gold in Nevada is disseminated. Usually disseminated shows up as perhaps between 1 and 4 grams per ton, over a fairly wide area (100's of meters), whereas vein gold can typically be over 100 grams/ton, but only in spots (such as one meter).

Over the life of a mine, I wouldn't say that one type of gold formation is necessarily "better" than another, but disseminated gold is easier to predict, and thus generally easier to finance development. With a disseminated ore body, you can usually estimate what's there via extensive drilling, but with vein gold you essentially have to follow it and mine it to know what's there. In other words, you don't quite know what you have with vein gold, until you've already mined it out. Although with some drilling, you might be able to guess as to whether a project is worth starting.

GORO.OB is an example of vein type gold formations. Since they figure that the start up costs will justify the mining, they plan to go ahead with that once permitted. They plan to just keep working it, and they really don't know if the gold will last 5 years or 50 years. But that's more easily justified where they are in Mexico, than apparently would be the case where Bonanza Hills is in Alaska. Which is what Millrock apparently decided.

Again though, the good news is that Millrock didn't conclude that there wasn't much gold there, they just decided that it's a vein type formation and thus they don't want to take the risks that go along with that. If gold goes much higher, say to $2000/oz, clearly the risk/reward situation there would be more justified. Or if someone does more drilling and feels somewhat more confident about the vein system, then possibly the value in mining would become more justified.