Agee describes NWA 7034 as a “different kind of volcanic rock” — a breccia, or conglomerate of fragments from rocks that were shattered by volcanic violence and then welded back together by the extreme heat. Those textural characteristics of NWA 7034 further distinguish it from the SNCs, as well as a fourth category of Martian meteorite available to scientists and represented by Alan Hills 84001. A much older meteorite recovered from Antarctica, AH84001 became the focus of contested claims in 1996 that it hosted fossilized evidence of Martian microbial life.
“There are a couple of ways to look at this high water content,” Agee says of NWA 7034.
In one scenario, a volcano emerges from the Martian terrain, heating the rock structure and melting the permafrost, allowing the two to interact before an asteroid or comet struck with enough energy to launch NWA 7034 on a trajectory that would intersect the Earth’s orbit.
In an alternate scenario, the Martian climate did not change so severely, permitting an interaction between the breccia and surface or ground water.