Someone else brought up that superoxygenator salts form in the upper layers of the soil due to the high UV radiation on the surface. It's possible the oxidation

Someone else brought up that superoxygenator salts form in the upper layers of the soil due to the high UV radiation on the surface. It's possible the oxidation here is due to those superoxygenators but the original manganese is due to the ancient lake. So basically manganese is embedded in the rock while there's a lake, then the lake dries up as the atmosphere disappears. And finally the UV gets strong enough to create oxidizers in the soil which react with the manganese.