Biological markers in 1.7 billion year old rock from the Tuanshanzi Formation, Jixian strata section, North China

n-Alkanes, isoprenoids, steranes, hopanes and gammacerane have been found in a 1.7 Ga old sedimentary rock. δ13C values of n-alkanes are almost identical (−30±1‰) whereas phytane and pristane have δ13C values of −28±0.5‰, similar to those in modern sediments. These compounds are also present in the kerogen thermolysis product, indicating that they are indigenous.