Study finds three water interactions in Mars lake margin unit

Findings published in Communications Earth & Environment describe three water interactions in the Margin Unit. The unit is the shoreline of an ancient Martian lake.

The Margin Unit is the shoreline of an ancient Martian lake and was expected to contain sedimentary rocks. Orbital observations detected strong carbonate mineral signals, and the unit also includes igneous rock.

SuperCam determines mineralogy from reflected light, and plasma spectra reveal chemistry. Perseverance examined more than 185 bedrock targets.

Coarse-grained crystalline olivine appears at higher elevations. The olivine unit formed in magma deep underground and reached the surface after erosion; olivine grains are fractured with silica.

The Margin Unit is described as a crossroads for aqueous systems. The first water event produced carbonate ridges, carbonate-filled fractures were left standing, and the second water event may relate to a lake.

Carbonate and silica minerals are signposts in ancient-life research. Interactions between water and olivine can release hydrogen, leaving carbonate and silica behind. The Perseverance team knows the sequence but not the age.

For readers tracking the lunar industry, the findings show how mineral measurements can separate distinct water events in a terrain. They also highlight carbonate and silica minerals as signposts for ancient-life research.