Effects of Organic Compounds on Dissolution of the Phosphate Minerals Chlorapatite, Whitlockite, Merrillite, and Fluorapatite: Implications for Interpreting Past Signatures of Organic Compounds in Rocks, Soils and Sediments.

Phosphate is an essential nutrient for life on Earth, present in adenosine triphosphate (ATP), deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and phospholipid membranes. Phosphorus does not have a significant volatile phase, and its release from minerals is therefore critical to its bioavailability. Organic ligands can enhance phosphate release from minerals relative to release in inorganic solutions, and phosphorus depletion in paleosols has consequently been used as a signature of the presence of ligands secreted by terrestrial organisms on early Earth.

Clay mineral formation under oxidized conditions and implications for paleoenvironments and organic preservation on Mars.

Clay mineral-bearing locations have been targeted for martian exploration as potentially habitable environments and as possible repositories for the preservation of organic matter. Although organic matter has been detected at Gale Crater, Mars, its concentrations are lower than expected from meteoritic and indigenous igneous and hydrothermal reduced carbon. We conducted synthesis experiments motivated by the hypothesis that some clay mineral formation may have occurred under oxidized conditions conducive to the destruction of organics.