RE: "obviously a recent event"I too think that the San Miguel soil anomaly is a recent event. So recent, in fact, that I think it is still forming! The anomaly being recent does not preclude its source being bedrock - they are not mutually exclusive.
I think that the ions are moving vertically upward by capillary action then as the aqueous solutions arrive at the surface the water evaporates leaving the metal behind. With this method the metal builds up at surface and increases over time. There is little metal in the soil much below surface because it is just moving through it like a pipeline. It only gets deposited near surface. If it is moved around on surface then it gets replenished with new metal ions arriving from below.
So as you can see the idea that the anomaly is recent has been embraced and not rejected.
Back in February I posted a Scanning Elecron Microscope image which i got by email from Briggs. The link to the post for those of you interested is:
https://199.175.179.211/bullboards/viewmessage.asp?no=4751580&tableid=2
Heres the image again:
Here's the text of the post:
'I got the following picture emailed from PLY. It is a scanning electron microscope picture. Apparently a regular microscope can't see these very small grains of loess. Also the Electron Microscope lets you identify the chemical composition of the various minerals. The top part of the picture is two graphs identifying different minerals and the bottom part is a picture of the grains. The coating is a zinc mineral, around a grain of loess. I guess this is what Vic saw when he was in the office. To me this supports the zinc arriving in solution and then precipitating out around the soil grains when the water evaporated near to surface. Briggs told me this sample came from a very high zinc part of the E1 South anomaly. As Vic observed PLY are doing more than the typical junior on this project.'
Owl