ador ▁County , ▁California . ▁ ▁Ge ology ▁Black ▁Ch asm ▁Ca vern ▁is ▁a ▁dissol ution ▁cave , ▁formed ▁by ▁sul fur ic ▁acid ▁resulting ▁from ▁Ge o - ther mal ▁hydro gen ▁sul f ide ▁react ing ▁with ▁down - mov ing ▁o xygen ated ▁surface ▁water . ▁This ▁er odes ▁the ▁lim estone ▁bed rock ▁to ▁form ▁small ▁to ▁very ▁large ▁ch amb ers . ▁It ▁is ▁considered ▁part ▁of ▁the ▁C ala ver as ▁Complex , ▁however , ▁the ▁cry stal ▁structure ▁of ▁the ▁rock ▁has ▁changed ▁over ▁time , ▁which ▁is ▁class ified ▁as ▁met am orph ic ▁and ▁is ▁now ▁properly ▁referred ▁to ▁as ▁mar ble . ▁Many ▁la kes ▁make ▁up ▁the ▁lower ▁levels ▁of ▁the ▁ca vern . ▁The ▁cal cite ▁form ations ▁in ▁Black ▁Ch asm ▁Ca vern ▁are ▁derivative ▁of ▁the ▁mar ble ▁bed rock , ▁containing ▁primarily ▁calci um ▁or ▁calci um ▁carbon ate ▁( Ca CO 3 ). ▁There ▁are ▁a ▁variety ▁of ▁form ations ▁in ▁Black ▁Ch asm ▁Ca vern , ▁including ▁stal act ites , ▁stal ag mit es , ▁columns , ▁flow stone , ▁dra per ies , ▁rib b ons , ▁ang el ' s ▁wings , ▁cave ▁ba con , ▁s oda ▁st raw s , ▁hel ict ites , ▁false ▁flo ors , ▁and ▁others . ▁ ▁Bi ology ▁Black ▁Ch asm ▁Ca vern ▁is ▁home ▁to ▁am ph ip ods , ▁which ▁live ▁in ▁the ▁la kes ▁of ▁the ▁cave . ▁The ▁am ph