▁were ▁toler able ▁enough ▁to ▁provide ▁reasonable ▁protection ▁from ▁the ▁elements . ▁In ▁the ▁north - western ▁corner , ▁a ▁chim ney - like ▁shape ▁tap ers ▁towards ▁a ▁ ▁wide ▁gap ▁in ▁the ▁ce iling , ▁a ▁gap ▁which ▁allowed ▁a ▁large ▁quantity ▁of ▁re dd ish - b rown ▁cl ay ▁to ▁o o ze ▁into ▁the ▁cave ' s ▁interior ▁during ▁the ▁Ple ist oc ene . ▁ ▁Str at ig raph y ▁ ▁Ex pl or ations ▁by ▁discover er ▁Robert ▁Rudolf ▁Schmidt ▁and ▁histor ians ▁Peter ▁Go ess ler ▁and ▁Albert ▁K ley ▁did ▁not ▁yield ▁notable ▁results . ▁T üb ingen ▁historian ▁Gustav ▁R iek ▁eventually ▁took ▁up ▁system atic ▁work ▁in ▁September ▁ 1 9 5 5 . ▁Over ▁the ▁course ▁of ▁eleven ▁exc av ation ▁sessions ▁that ▁last ed ▁until ▁October ▁ 1 9 6 3 , ▁he ▁un ear th ed ▁eleven ▁sed iment ▁profiles . ▁R iek ▁recognized ▁and ▁determined ▁a ▁total ▁of ▁ 2 2 ▁distinct ▁layers , ▁of ▁which ▁only ▁ 3 ▁were ▁considered ▁post - P le ist oc ene ▁in ▁origin . ▁The ▁work ▁yield ed ▁numerous ▁stone ▁and ▁b one ▁tools , ▁iv ory ▁j ew el ry , ▁human ▁ske let al ▁remains ▁and ▁pot tery ▁sh ards . ▁ ▁During ▁the ▁early ▁ 1 9 9 0 s , ▁T üb ingen ▁arch ae ologist ▁Anne ▁Sche er ▁succeeded ▁in ▁conclus ively ▁demonstr ating ▁that ▁the ▁occup ations ▁of ▁Br ill en hö h le ,