Cave of Crystals, Naica Mine, Mexico
^BCave of Crystals.^b Geologist in the Cave of Crystals (^ICueva de los Cristales^i) in Naica Mine, Chihuahua, Mexico. The crystals are the largest known in the world, and are formed of the selenite form of gypsum (calcium sulphate). They formed over millions of years in the mineral-rich geothermally heated water that filled the caves. The crystals were discovered after the water was pumped out of the mine. The Cave of Crystals is 290 metres deep, and was discovered in 2000. Above it, 120 metres deep, is the Cave of Swords (^ICueva^i ^Ide^i ^Ilas Espadas^i), which was discovered in 1912. The crystals in this cave are smaller as its water cooled more rapidly.
© JAVIER TRUEBA/MSF/SCIENCE PHOTO LIBRARY
Ancient artist at work in a cave, Kazakhstan area
Andronovo culture, ancient artist painting petroglyphs on the rocks, conveying the culture and customs of the times, Kazakhstan area. Others watch, or help by supplying light from a flaming torch.
© AEO Nazarbayev Intellectual Schools / Mary Evans
Ancient, Andronovo, Art, Artist, Cave, Conveying, Cultural, Culture, Customs, Drawing, Flaming, Kazakhstan, Light, Paint, Painting, People, Petroglyph, Petroglyphs, Rock, Rocks, Stone, Times, Torch, Wall, Watch
Tourists descending steps to entrance of Gruta do Lago Azul Cave (Blue Lake Cave)
Tourists descending steps to entrance of Gruta do Lago Azul Cave (Blue Lake Cave). Fossil bones of Sabre tooth tigers, Giant sloths and armadillos have been found in this and the neighbouring cave: Gruta de Nossa Senhora Aparecida. Gruta do Lago Azul Natural Monument, Bonito, Mato Grosso do Sul, Brazil
© Attila Bicskos Kaszo/AUSCAPE All rights reserved