Blam may have something there. I see white alkali sediment that has been washed down into a few of the wet areas by snow melts from hills covered with sterile soil on this intermontane basin (more like a plateau). Lack of fertilization here due to residents shouting ubergrazing! over the years (mostly residents in government or retired from government always engaged in keeping productive riff-raff out). The land has been mostly unused for a very long time.
Fertilization (heavy farming) eventually lowers PH levels. Hard-packed, sterile soil PH tends to rise to a high alkali content.
[Experimenting with low-cost gardening—and yaks soon—on an extremely cold and windy place at a high elevation.]
Oops...pH, even.
Thanks!