Lunar and Planetary Institute
Lunar and Planetary Institute



Ancient Groundwater Flow on Mars

February 28, 2008

Fault lines and fault-trace ridges (FTR) between the canyons Melas Chasma and Candor Chasma in the Valles Marineris. On the high plateau to the west (left), fault lines run east-west as the boundaries of down-dropped fault blocks (i.e., graben).These fault lines contine eastward beyond the edge of the plateau as fault-trace ridges, some of which are marked with arrows. Image is from the HRSC camera on the Mars Express orbiter; center at Mars coordinates 7.90°S, 285.61°E.Dr. Allan Treiman, Senior Staff Scientist at the Lunar and Planetary Institute, published his recent findings in “Ancient Groundwater Flow in the Valles Marineris on Mars Inferred from Fault Trace Ridges,” which appeared in the February 24 issue of Nature Geoscience.

Treiman and an LPI student intern first presented these ideas at the Lunar and Planetary Science Conference in 1996. But few people came to view their poster, and the work was shelved. It was not until last year, when Chris Okubo of the Lunar and Planetary Laboratory at the University of Arizona reported similar features in a Science article, “Fracture-controlled Paleo-Fluid Flow in Candor Chasma, Mars,” that Treiman revived these old studies.

“This work has always been in the back of my mind, but it didn’t seem that the community was interested,” said Treiman.

Treiman began refining his work until he was ready to once again present his findings. He explains that the fault trace ridges, which are over 100 kilometers long, are the major terrain boundaries between the canyons. Usually, fault lines appear as valleys (not ridges) because the fault motions and earthquakes break up the rock. For fault zones to appear to resist erosion, and appear as ridges, their broken rock must be cemented together. On Earth, the cements are usually minerals (like silica and calcite) deposited by flowing groundwater.

The length of the fault trace ridges (up to and over 100 kilometers) and their depth (over 5 kilometers) suggest that the faults acted as “pipes” for huge volumes of water. The flow was probably west-to-east, from the Tharsis volcanos and eventually downward toward Mars’ northern lowlands. The fault trace ridges appear up to the surface of the nearby high plateaus, which suggests that liquid  water was stable at or near the martian surface when the fault zones were cemented; liquid water is not stable now at Mars’ surface.

While there are many theories on where the groundwater originated, understanding the flow is important for assessing the possibility of past and present martian life, as well as future habitability.

To read the Nature Geoscience article, visit

Ancient Groundwater Flow in the Valles Marineris on Mars Inferred from Fault Trace Ridges

For more information Mars groundwater flow, visit

Treiman and Spiker's 1996 LPSC Abstract

How Groundwater Shaped Mars

For more information on Dr. Allan Treiman, visit

Dr. Treiman’s Web page


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Last updated May 22, 2008