▁with ▁a ▁m ora ine ▁has ▁been ▁found ▁in ▁the ▁n ort he astern ▁side ▁of ▁the ▁Cer ro ▁C um bre ▁Neg ra ▁sum mit ▁next ▁to ▁an ▁Az uf rera ▁stage ▁la va ▁flow . ▁A ▁small ▁m ora ine ▁lies ▁on ▁the ▁south ▁side ▁of ▁the ▁Ang ulo ▁ed ifice ; ▁some ▁la vas ▁from ▁that ▁ed ifice ▁over lie ▁gla cial ▁depos its . ▁ ▁Human ▁activity ▁and ▁min ing ▁▁ ▁A ▁mine ▁at ▁ ▁alt itude ▁that ▁yield ed ▁ore ▁with ▁ 3 0 % ▁sul fur ▁was ▁opened ▁by ▁Julian ▁B . ▁Car ras co ▁in ▁ 1 9 1 3 , ▁who ▁subsequently ▁established ▁the ▁Com pa ñ ía ▁Min era ▁y ▁Az uf rera ▁Car ras co ▁S . A ▁in ▁ 1 9 3 3 . ▁The ▁sul fur ▁was ▁transport ed ▁down ▁first ▁with ▁llam as , ▁later ▁through ▁an ▁aer ial ▁cable way ▁system ▁and ▁finally ▁by ▁tr uck s . ▁The ▁sul fur ▁was ▁then ▁transport ed ▁to ▁Ch u qu ic am ata ▁to ▁be ▁converted ▁into ▁sul fur ic ▁acid . ▁The ▁mine ▁was ▁active ▁from ▁ 1 9 5 0 ▁to ▁ 1 9 9 2 . ▁The ▁last ▁reported ▁min ing ▁activity ▁on ▁the ▁mountain ▁was ▁in ▁ 1 9 9 4 . ▁In ▁ 1 9 7 7 ▁other ▁sul fur ▁mines ▁were ▁present ▁to ▁the ▁west ▁between ▁Cer ro ▁Pol an ▁and ▁Cer ro ▁G ordo ▁and ▁south ▁of ▁the ▁main ▁A uc an qu