EARTH × LIFE

The Doushantuo Phosphate Boom

~630 to 574 million years ago

Proterozoic · Neoproterozoic · Ediacaran

The Doushantuo phosphate boom is the first accumulation of phosphate in marine sediment in quantities worth mining, between 630 and 574 million years ago, and its beds in South China still supply much of the world's phosphorus.

The Doushantuo phosphate boom is the first phosphogenesis in the planet's history, that is, the first accumulation of phosphate, a compound of phosphorus, in marine sediment in quantities worth mining. The Doushantuo beds of South China were deposited between 630 and 574 million years ago and still supply a large share of the world's phosphorus. They formed while the first large eukaryotes, organisms whose cells have a nucleus, were spreading through the same seas. Phosphorus is the limiting nutrient of marine production, the nutrient whose scarcity limits it.

Why it matters

Over long timescales, phosphorus determines how much life an ocean can feed, because it is the nutrient that runs out first. A rock made of phosphate is therefore a quantitative record. It shows that, whatever the other conditions, more phosphorus was passing through the sea when the rock formed than ever before, and that the surplus was being buried.

Dating & uncertainty

The phosphate accumulated in two distinct pulses. The lower beds, around 630 to 600 million years ago, have the chemical signature of continental weathering, the breakdown of rock on land. The upper beds, around 587 to 574 million years ago, have that of upwelling, the rise of deep water towards the surface. It is unresolved whether either pulse caused the rise of animals or merely accompanied it.

Earth history as one day

20:40:103 h 20 min before midnight

if Earth’s 4.54 billion years were compressed into a single day