"The original HiRISE satellite image supplied to Mail Online by the University of Arizona showing a close up of what appears to be a 'monolith' on Mars..."
"speaking about the satellite picture scientist Alfred McEwen, the principal investigator from the University of Arizona's HiRISE department, said: 'There are lots of rectangular boulders on Earth and Mars and other planets.
'Layering from rock deposition combined with tectonic fractures creates right-angle planes of weakness such that rectangular blocks tend to weather out and separate from the bedrock.'
Fuel was added to the flames after Buzz Aldrin, the second man to walk on the Moon, alluded to a similar monolith detected on Mars' moon Phobos.
Speaking on a U.S. cable television channel last week he said: 'We should visit the moons of Mars.
'There's a monolith there - a very unusual structure on this little potato shaped object that goes around Mars once every seven hours."
http://www.dailymail.co.uk/sciencetech/article-1204254/Has-mystery-Mars-Monolith-solved.html
Adapted from U.S. Geological Survey photo by S. R. Brantley.
Large eruptions of basalt lava may create deep flows of molten rock. As the rock slowly cools it shrinks slightly. The stresses cause jointing in several different planes, and columns of rock form with a generally hexagonal shape, like pencils. The flow shown here is at Sheepeaters Cliff, in Yellowstone National Park. Note that there is a strongly developed horizontal jointing here, too.
The piece of basalt below displays the six-sided cross section of a column. Some columns may have five or seven sides instead.
http://geology.about.com/library/bl/images/blbasaltcolumns.htm
Adapted from U.S. Geological Survey photo by S. R. Brantley.
Large eruptions of basalt lava may create deep flows of molten rock. As the rock slowly cools it shrinks slightly. The stresses cause jointing in several different planes, and columns of rock form with a generally hexagonal shape, like pencils. The flow shown here is at Sheepeaters Cliff, in Yellowstone National Park. Note that there is a strongly developed horizontal jointing here, too.
The piece of basalt below displays the six-sided cross section of a column. Some columns may have five or seven sides instead.
http://geology.about.com/library/bl/images/blbasaltcolumns.htm
Everything after “But 4 flat sides is very odd in nature.” was from the website I linked to.
Apparently some are at right angles to each other. That could possibly explain the 4-sided structure of the monolith as impact-ejected rock.