Grzegorz Gawlik on different continents and in different climates. Among other things, he discovered the highest lakes in the world on the Ojos del Salado volcano and found that the highest active volcano in the world is Llullaillaco. In addition, he explored more than 100 other volcanic sites such as geyser fields, geothermal fields, volcanic caves, volcanic deserts, volcanic plateaus, volcanic craters and cones, volcanic rock formations, lava fields. He climbed to about 100 peaks 4-, 5-, 6- and 7-thousand meters in the Himalayas, Andes, Pamir, Caucasus, Cordillera, High Atlas, Tanzania, Borneo and hundreds of lower peaks. During the expeditions, Gawlik explored
Ojos del Salado of fumaroles high on the mountain and recent-looking lava flows, albeit of uncertain age, also argues in favor of a categorization as "active." By these definitions, Ojos del Salado is the highest historically active volcano on Earth. If the older date is accepted, the title of "highest historically active volcano" might reside instead with the somewhat lower Llullaillaco volcano, which certainly has erupted in historic times (most recently in 1877) and is considered active. Salado's rock is predominantly potassium-rich dacite and rhyodacite. Its lavas are high in biotite, hornblende, plagioclase, and opaques, with lower levels of augite, quartz, and hypersthene.