Geochemistry. Minerals cooked up in the laboratory call ancient microfossils into question.
Kerr
Richard A
RA
D001315:Australia; D001464:Barium / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry*; D019369:Life; D009930:Organic Chemicals / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013696:Temperature
D002254:Carbonates; D009930:Organic Chemicals; D001464:Barium; D012822:Silicon Dioxide