Quantified EPMA elemental map showing the CaO concentration of meteorite RBT 04262, a "poikilitic shergottite", essentially a basalt erupted in a volcano on Mars. The colors highlight the different minerals of the rock. The Ca-rich pyroxene marks the boundary between two lithologies, a poikilitic texture in the lower right and an olivine-phyric basaltic shergottite texture on the left. The RBT 04262 was found in the Roberts Massif of the Transantarctic mountains of Antarctica in 2006.
Recorded on CAMECA SX 100 at NASA-Johnson Space Center, Houston Texas, USA. Image courtesy of A. Peslier.