This is in response to a PM, but is worth sharing.

Much of the desert Southwest is covered in Pleistocene-era lake sediments. In other words, clay. These soils are clearly visible at surface across broad areas around Tombstone, especially north towards Beson, where not interrupted by such as granite and other intrusives.

In my opinion, this accounts for the differences in shading apparent in aerial photos around Hay Mountain, and should have little to do with Lithium. Besides, I believe it has aready been reported that REEs, it they exist in economic quantities, are at very deep levels below Hay Mountain and likely in hard rock, so evidence should not be visible at surface, especially in regards to what looks to be lake sediments.

I am not a credentialed geologist, so takes this as opinion.

VP