Ancient Groundwater Flow on Mars
February 28, 2008
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
For more information Mars groundwater flow, visit
For more information on Dr. Allan Treiman, visit
May 22, 2008