Marine phosphorus cycling & burial through time

We've previously suggested that organic matter remineralization was muted in the Precambrian ocean due to a scarcity of oxidants. One implication is that recycling of phosphorus within the ocean would've been limited, keeping Precambrian phosphate levels low. Because P limits marine primary productivity on geological timescales, this would've hampered productivity until oxidants (namely oxygen and sulfate) became more abundant in seawater. We're now using various approaches to test this hypothesis in the geologic record, including multi-proxy chemostratigraphic studies of phosphorites from around the world (including the Permian Phosphoria Fm, pictured below).