Pisoliths would be a great discovery but the formation hits this old field-tripper's eye as lithophysae or, to use less technical terms, spherulites or mini-thundereggs. I've rolled tens of thousands of identical-looking little rhyolite balls from tuff and perlite beds from the Idaho-Oregon border to central Oregon.
If that's what they are, it would support my case made on another thread that the outcrops are volcanic ash (tuff). Here's what one authority has to say:
"Ross and Smith (1961) simply define thunder eggs as uncommonly large lithophysae (i.e., hollow gas cavities; Greek derivation = "stone bubble") that develop in a welded tuff (welded tuffs are composed of a "plastic" volcanic ash that becomes indurated, or fused, by the internal heat that is inherent in the erupted rock [Thrush 1968]).
"Thunder eggs are generally defined as nodular structures (Staples [1965] emphasized that they should be considered structures, not "rocks") that are formed within high-silica extrusive volcanic rocks or welded tuffs, with the silica content of the rock ranging from 75 to 80 percent (Dake 1951; Renton 1951; Staples 1965)."
I'm aware of your [doodad's] objection that olivine and quartz (silica) don't occur together. I've searched and can't find any report of olivine at this site although it's mentioned at the Spirit site. Maybe I missed it.