Colloids, Flocculation, and Au Hyperenrichment at the Brucejack Deposit with Duncan McLeish

What are we observing versus what are we supposed to see, in other words, how (and how much) is dogma directing our interpretations? We explore this concept this month when we delve into Duncan McLeish's PhD work on the transport and deposition of gold at the Brucejack Deposit (Canada).  In a world where aqueous complexation has long been considered the only viable means of transporting gold to depositional sites in hydrothermal ore-forming systems, Duncan et al. found that rejecting dogma was of the utmost importance. For example, a major weakness of the Au transport in solution hypothesis is that it cannot readily explain the formation of ultrahigh-grade gold veins when transporting Au at ppb levels. ...so how do “bonanza” veins contain weight-percent levels of gold in some epithermal and orogenic deposits? ...what are colloids and flocculation? ...why is this research both exciting and important?  All this and more in this episode! Put on your thinking caps, it's time to listen to some applied chemistry, economic geology and a little bit of philosophy.  For this episode we read "Colloidal transport and flocculation are the cause of the hyperenrichment of gold in nature" by McLeish et al., 2021.