Geologically recent water flow inferred in channel systems in the NE Sulci Gordii region, Mars

A series of fluid-carved channels in the Sulci Gordii region of Mars were investigated. Numerous channel networks exist in Sulci Gordii, part of the Olympus Mons aureole, and this area comprises some of the youngest volcanic terrain on Mars. The channels ranged in length from 43 to 155 km, with widths of 128–288 m. The morphology of the channels was analysed assuming both lava and water as possible agents. For three of the four channels studied, water appears to be the likely agent, while one channel is probably lava-formed. For the water-formed channels, discharge rates were estimated at 8000–36 000 m3 s?1. The lava channel was probably formed from short-lived episodic activity by a low-viscosity lava. The age of the channels and surrounding area was estimated using crater counting to be 100 Ma. Water has appeared to have flowed for almost 150 km under the climatic conditions at this time. There is some evidence for later tectonic activity, possibly as recent as 10 Ma, but crater-dating accuracy was limited by the lack of high-resolution images of some areas. Sulci Gordii is therefore a dynamic site with evidence of hydrological and volcanic activity extending into the recent geological past.