Mom told me I have to come and explain Peavine Mountain...
Peavine is a rotated fault block, topped with granodiorite and locally metamorphosed through hydrothermal action so that there are minable veins of copper (with associated minerals). But by Reno's elevation it is mostly alluvial fans, sedimentary deposits like diatomite (old lake beds), lenses of washed out glacial till, and weathered lahar deposits from the andesite flows off the Sierras. So her backyard is an unreasonable mismash of andesite blobs, the occasional semi-metamorphosed sedimentary rock, crumbling clay and diatomite chunks. The size ranges from sand to large cobbles and is roughly sorted in that way that alluvial fans have. Water drains incredibly fast through the stuff. There are some beautifully exposed normal fault offsets exposed in the neighborhood retention ponds.
Mom's picked up chert, agates, petrified wood and chunks of chalk in the yard.
And then there are the granite and granodiorite chunks the builder used as rick-rack.... Definitely not local, but rather pretty.
