ISS012-E-6456 Click the photo number to access all resolutions available and the database record.
This astronaut photograph features the northern end of the salar and the dormant volcano Mount Tunupa (image center). This mountain is high enough to support a summit glacier, and enough rain falls on the windward slopes to provide water for small communities along the base. The dark volcanic rocks comprising Mt. Tunupa are in sharp contrast with the white, mineral-crusted surface of the salar. The major minerals are halite—common table salt—and gypsum—a common component of drywall.
Relict shorelines visible in the surface salt deposits (lower right of the image) attest to the occasional presence of small amounts of water in the salar. Sediments in the salar basin record fluctuations in water levels that occurred as the lake that once occupied the salar evaporated. These sediments provide a valuable paleoclimate record for the region. The dynamic geological history of the Altiplano is recorded in isolated “islands” within the salt flat (image left); these islands are typically built from fossil coral reefs covered by Andean volcanic rocks.
