Madagascar's Saririaky massif features moon-like anorthosite

An astronaut aboard the International Space Station captured an image of the Saririaky anorthosite massif in southern Madagascar. The bright, highly reflective igneous rock is similar to the anorthosite that forms the lunar highlands on the Moon.

Scientists believe the massif formed during the late Precambrian, at least 600 million years ago, and covers approximately 100 square kilometers. The surrounding rocks indicate the massif lies within a ductile shear zone, where high pressure and temperature reshaped the rock into north-south-trending linear patterns. Geologists suggest this deformation occurred during the collision of landmasses that formed the supercontinent Gondwana.

Because lunar anorthosite samples brought back by Apollo astronauts are limited, researchers use Earth-based anorthosite outcrops as analogues to study the Moon’s geological history.