Dallol: Hot springs
Geologically, Dallol is a most remarkable place: Situated in the Danakil depression, it is nearly 120 meters below sea level. Below a salt lake is a substantial source of volcanic heat which causes hot water to rise through layers of salt and anhydrite deposits. Minerals get dissolved and are deposited, near the springs, and form shapes very much reminiscent (but smaller than) hornitos on basaltic lava flows. Sulphur, other minerals and possibly thermophyle bacteria cause spectacular colours.
Typical group of active «hornitos» up to about one meter high.
Boiling water spurts out from an active «hornito».
Fresh deposits form bright yellow terraces, while older deposits (background) have become brown due to weathering.
Some of the larger terraces dam ponds of up to about one meter in diameter.
Old, inactive «hornitos» quickly lose their lustre and gradually turn beige and, later, brown.
Contrast between youngest deposits (white), a little older (yellow) and several months old (brown or black; background).
Typically Dallol springs form small clusters building up miniature «citadels» like the one in the foreground and another further back.
Alien sculptures on display in an alien landscape. Are we still on planet Earth?
In this remarkable small, green pond particularly large salt crystals are forming.
Thin floes of salt on the surface of this pond may have formed at night due to lower temperatures and lower solubility in the water.
A somewhat more substantial floe adorns this jewel of a pond. During the midday heat it all dissolved in the water.
One of the flat, low areas where the water from the springs ends up and gradually evaporates.
«Mineral exhibition» in the desert: Salt and sulphur crystals.
Eggs of aliens? Remarkable mineral deposits around small scale steam vents.
A larger, complex, «egg» all on its own.
Roby's set-up for videography. The microphone records noises from the spring.
Tiny salt stalactites have been sculptured by the strong desert winds.
The green ponds amongst the orange and yellow sulfur and salt deposits were our favorite features at Dallol.
And also a second picture of the «green pond» after the salt floe has disappeared.
Minerals probably other than salt have crystallized around a minute crack in the ground.