Controls on the Precipitation of Carbonate Minerals Within Marine Sediments

The vast majority of carbonate minerals in modern marine sediments are biogenic, derived from the skeletal remains organisms living ocean. However, can also precipitate abiotically within sediments, and this mineral precipitation has been suggested as a third major, isotopically distinct, sink global carbon cycle, particularly important earlier Earth history. Here we present compilation pore fluid data compare sulfate, calcium, phosphate magnesium concentrations with alkalinity to explore emerging relationships what drives sediments. Our shows that gradient sulfate correlates strongly well these correlations improve dramatically where methane is present. We note sedimentary fluids high concentration alkalinity, which may indicate suppression presence phosphate. be used highlight both dolomite formation dolomitization previously deposited calcium occurring. how saturation state changes function concentrations, pH, suggest reason why never fully depleted fluids. conclude methane, anaerobic oxidation helps promote states for minerals.