University of Alberta geochemists have discovered a missing piece to one of the great mysteries of science — the origin of life on Earth.

That fateful spark is believed to have occurred on the ocean’s floor, fuelled by warm, mineral-rich hydrothermal vents. But scientists have long puzzled over how the right fertilizer — particularly the forms of carbon and nitrogen necessary to create and sustain life — could have existed without the benefit of the sun.

After analyzing rock samples from hydrothermal vents drilled over a depth of about 200 metres into the crust in the South China Sea, Long Li and his team in the Department of Earth and Atmospheric Sciences found evidence of a chemical process — called abiotic nitrogen reduction (ANR), a reaction driven by minerals as catalyst — that likely produced the necessary nutrients for life. A key part of those is ammonium, says Li, crucial for the abiotic synthesis of organic compounds to develop the first life.