A review of phosphate oxygen isotope values in global bedrocks: Characterising a critical endmember to the soil phosphorus system

Understanding the phosphate oxygen isotope (δ18O-PO4) composition of bedrock sources is becoming ever more important, especially in areas soil research which use this signature as a proxy for biological cycling phosphorus (P). For many these studies, obtaining sample source or applied mineral fertiliser analysis impossible; meaning there now demand comprehensive characterisation global δ18O-PO4 to support work. Here we compile data from wide range bedrocks, including 56 new values produced part study and overview those within previously existing literature. We present major phosphatic lithologies alongside much metadata samples could be gathered. Much comes bedrocks marine sedimentary origin (< 1 Ma = > +22‰, 540 ≈ +12‰), but also associated with guano (range: +19.5 +15‰) igneous deposits +12 –0.8‰), both have distinct signatures due their formation mechanisms. show that where repeat measurements same been undertaken, regardless method exact location, an average error ± 1.25‰. This constitutes reasonable level uncertainty studies need estimate based on In combination, set presents 284 countries; starting point researchers interested understanding end member δ18O-PO4.