Abismo Guy Collet
The Abismo Guy Collet (SP-090) is the deepest cave in South America, and the deepest in the world that is formed in quartzite. Located in a tepui in northern Brazil near the border with Venezuela, this cave was first explored by cavers in 2006 to a depth of 671 meters.
Levan Maruashvili
Levan Iosifovich Maruashvili ( born 25 October 1912, Novocherkassk, Russian Empire, — 5 December 1992, Tbilisi, Georgia) was a prominent Georgian geographer. Doctor of Geographical Sciences (1954), professor (1965). Honored Scientist of the Georgian SSR (1966) and Abkhaz ASSR. Honorary member of the Russian Geographical Society (1985). He introduced a new concept of karst-sphere into the science. Krubera Cave, which is the world’s deepest known cave (2197 m), was discovered by the Georgian researchers in 1960 by the leadership of Professor Levan Maruashvili.