▁These ▁turning ▁and ▁b ending ▁form ations ▁are ▁known ▁as ▁hel ict ites ▁and ▁are ▁an ▁unusual ▁formation ▁in ▁cave ▁systems ▁throughout ▁the ▁world . ▁Some where ▁near ▁the ▁ 1 8 6 0 s , ▁the ▁cave ▁entrance ▁was ▁en larg ed ▁from ▁its ▁original ▁ 1 8 " ▁wide ▁crack ▁in ▁order ▁to ▁accommod ate ▁st airs ▁for ▁t ours . ▁The ▁t ours ▁last ed ▁only ▁a ▁short ▁time ▁before ▁the ▁cave ▁was ▁abandoned . ▁ ▁Following ▁the ▁gold ▁r ush , ▁Black ▁Ch asm ' s ▁name ▁f aded ▁from ▁recent ▁memory ▁amongst ▁the ▁population ▁only ▁to ▁be ▁redis cover ed ▁with ▁a ▁res urg ence ▁in ▁c aving ▁interest ▁in ▁the ▁ 1 9 5 0 s . ▁One ▁early ▁expedition ▁is ▁cred ited ▁with ▁discover ing ▁the ▁rare ▁and ▁pro l ific ▁display ▁of ▁hel ict ites ▁in ▁the ▁Land mark ▁Room ▁in ▁ 1 9 5 4 . ▁In ▁ 1 9 6 2 , ▁a ▁diver ▁entered ▁into ▁Lake ▁Ref lection , ▁one ▁of ▁the ▁many ▁la kes ▁in ▁the ▁cave , ▁and ▁desc ended ▁to ▁ 6 5 ' ▁in ▁depth ▁before ▁hitting ▁bottom . ▁This ▁d ive ▁took ▁place ▁in ▁summ ert ime ▁when ▁the ▁fl uct u ating ▁lake ▁level ▁is ▁at ▁its ▁lowest . ▁In ▁ 2 0 0 1 , ▁the ▁lake ▁was ▁div ed ▁again , ▁during ▁it ▁highest ▁level , ▁when ▁the ▁diver ▁hit ▁ 8 0   fe et ▁in ▁depth . ▁While ▁there ▁are ▁no ▁known