Thanks, consuelo. The definition of "caliche" in my dictionary seems not to fit your description, and I think yours is to be preferred. The dictionary speaks of alternating very wet and dry seasons bringing up dissolved calcium carbonate which then dries out on the surface. In my freshman year in high school my home room teacher taught Spanish she learned as a girl with her father, who was a prospector in Southwest. I still remember her telling about their leading a couple pack burros up an arroyo when suddenly her father grabbed her and dashed up the banks just seconds before a wall of water came tearing down the dry gully.
I don't remember her praising the odor of caliche on that occasion.