This mosaic shows a series of sinuous lava flows in the Elysium region of Mars. The lava flowed from south to north (toward the top of the image). Individual flows are estimated to have average thicknesses of 60 meters. The flows are probably basalts, similar to lava flows in Hawai'i. The region shown is about 90 kilometers across.
Mosaic of Viking Orbiter images 651A08-651A12. Image processing by Brian Fessler, Lunar and Planetary Institute