Lithology-constrained phosphorus (P) releasement

Phosphorus (P), as an indispensable nutrient element in Earth’s biological system, exerts a pivotal role on the burial of organic carbon over million-year time scales. By producing oxygen and consuming carbon dioxide, organic carbon burial may have paved the path for multicellular organisms by reforming the anoxic atmosphere to an oxic one. Organic carbon burial, on long time scales, is ultimately limited by continental P influx released by chemical weathering of P-bearing minerals. As crystalline rocks characterized by prominent discrepancy in P-bearing mineral composition undergoing various dominant weathering forces on surficial environment, P availability for organic carbon burial could be controlled by lithology. To decipher the conundrum of P releasement, a catchment scale case study was conducted, encompassing a series of lithologies following the crystalline rock order. Preliminary data suggests that the P release efficiency is lithology-constrained, indicating an enhanced P releasement in felsic catchment. The result gives us a hint that felsic crust would export more P to the ocean and promote the organic carbon burial, the lithology-constrained P releasement also enlightens us a new perspective to understand the coevolution among crust, atmosphere and life.