Perseverance is investigating a field of pale boulders beyond Jezero crater after months in the Lac de Charmes region. Initial measurements suggest that many could be gabbro, a rock formed as magma cools deep underground. A single NASA mission update describes surrounding fragmented bedrock that may hold clues to their arrival at the surface. An ancient impact remains an interpretation under investigation.
NASA’s Perseverance rover encountered a broad spread of light-toned boulders beyond the western rim of Mars’s Jezero crater. A single mission update describes the investigation after six months in Lac de Charmes, an area of ancient rock. Dark basalt is common on Mars, making the concentration of pale blocks noteworthy. Imperial College London doctoral researcher Alex Jones described the team’s examination of their textures and composition.[1]
Initial data suggest many blocks are gabbro, an igneous rock containing minerals rich in iron and magnesium. Gabbro usually develops as magma slowly cools and crystallises deep in the crust. The team is investigating how possible fragments of that deep material reached the surface. Composition measurements are being considered alongside texture and the relationship between the blocks and surrounding bedrock.[1]
Between the boulders, Perseverance examined possible exposed bedrock containing angular fragments of both pale and dark material. Geologists call this kind of fragmented rock breccia. The scattered blocks may have weathered out of it. Similar breccia layers previously seen beyond Jezero have been linked to early asteroid impacts. An impact, possibly the one that formed Jezero, is being considered for these blocks; it remains an explanation under investigation.[1]
