Did you mean “alkali”?
One of my Facebook friends has taught elementary-school science, and once took her class to a wooded area in the region to collect various specimens, including creek water. They actually found a cow skull out in the woods, here in Iowa. For her, that was quite a find.
A few become fossils and can be found millions of years later. Ask Sue, from South Dakota.
That would be “just around the bend” from Abiquiu, where that one woman could not find anything else to paint.
(Just around the bend relative to most of the rest of us.)
For a time I lived in her old studio. It was cool because all of her art friends that stayed there wrote their names on the kitchen wall. Interesting history.
That’s “just up the street” from me. I have found bones (not skulls though) in some of our canyons.
Tripler
Non-radioactive bones, if-ya-get-my-drift.
Yeah, it’s real enough. I’ve seen dead cows in the desert while wandering around…as well as cows and other animals in various stages of decomposition (I know, totally yucky). And I’ve seen cow skulls on people’s property as well. I recall there was a bull skull with horns that was in my folk’s ramada in Tucson when I was a kid.
I don’t know the exact cause of death in any of these cases, but I’d guess most are natural, not human-driven (or aliens 
).
Ditto to all of this. I’ve been blocked on roads twice in the CA Mojave by belligerent herds of semi-feral longhorns. This was in very arid high desert.