UW News

Eva Stüeken

November 27, 2017

Less life: Limited phosphorus recycling suppressed early Earth’s biosphere

As Earth's oxygen levels rose to near-modern levels over the last 800 million years, phosphorus levels increased, as well, according to modeling led by the UW's Michael Kipp and others. Accordingly, Kipp says, large phosphate deposits show up in abundance in the rock record at about this time. This is a Wyoming portion of The Phosphoria Formation, a deposit that stretches across several states in the western United States and is the largest source of phosphorus fertilizer in the country. The photo shows layers of phosphorus that are 10s of meters thick, shales the contain high concentrations of organic carbon and phosphorus. Kipp said many such deposits are documented over time but are rare in the Precambrian era. "Thus, they might represent a conspicuous temporal record of limited phosphorus recycling."

The amount of biomass – life – in Earth’s ancient oceans may have been limited due to low recycling of the key nutrient phosphorus, according to new research by the University of Washington and the University of St. Andrews in Scotland.