4.4 Billion Year Old Meteorite Represents the Bulk of Mars’ Crust

A few years ago, in a desert in Morocco, a very special meteorite was found.  A rock unlike anything ever found on Earth, called NWA 7034, or colloquially ‘black beauty.’  Chemical analysis in 2011 found that it originated on Mars, but it was even unlike any other Martian meteorite discovered.  The scientific community was extremely excited to determine its properties through a spectroscopic analysis, and today we have some answers that are as amazing as we expected.

NWA 7034, Black Beauty, weighing 200 Grams. Credit: NASA

A new paper detailing spectroscopic results of the meteorite reveal that its composition is the same as the composition of the dark Martian plains obtained by orbiting satellites, where the dust layer is thin and the deep rock layers are exposed.

Prior to Black Beauty, all the Martian rocks discovered on Earth were classed as SNC meteorites (shergottites, nakhlites, or chassignites), mostly made of igneous rock from cooled volcanic material.  Black Beauty is called a Breccia, a mashup of different sedimentary rock types that are similar to those found by the Mars rovers.  Scientists concluded that it is a piece of the Martian crust, the first ever such piece to reach Earth.

The researchers say the match between the orbital observations and the spectral analysis of Black Beauty suggests that the dark plains regions of Mars are dominated by brecciated rocks similar to Black Beauty. Because the dark plains are dust-poor regions, they’re thought to be representative of what hides beneath the red dust on much of the rest of the planet.

“This is showing that if you went to Mars and picked up a chunk of crust, you’d expect it to be heavily beat up, battered, broken apart and put back together,” says Kevin Cannon, a graduate student at Brown University and lead author of the paper. “It’s representative of the bulk background of rocks on the Martian surface.”

Brecciation of rocks is largely due to impacts, and with Mars being punctured by over 400,000 impact craters, the whole surface is likely made of churned up and fused sedimentary rocks like Black Beauty.

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