National Aeronautics and Space Administration scientists say the fractures that were created billions of years ago directed flows of water through underground Martian sandstone. NASA said the fractures are of type called deformation bands, caused by stresses below the surface in granular or porous bedrock.

"Groundwater often flows along fractures such as these and knowing that these are deformation bands helps us understand how the underground plumbing may have worked within these layered deposits," said Chris Okubo of the U.S. Geological Survey in Flagstaff, Ariz.

NASA said visible effects of water on the color and texture of rock along the fractures provide evidence that groundwater flowed extensively along the fractures.

Okubo said the structures are important sites for future exploration into the geological history of water and water-related processes on Mars.

The discovery is reported online in the Geological Society of America Bulletin.