A search for iridium in the Deccan Traps and Inter‐Traps

It has been suggested that flood basalts in the Deccan (India) might be associated with events at the Cretaceous‐Tertiary boundary (KTB). A search for iridium in 47 samples from lava flows and inter‐trap sediments in the Deccan yields negative results. Concentrations are not statistically different from zero, with a minimum detection level on the order of 0.1 ng.g−1 (ppb). This does not help to constrain the debate on the internal vs external origin of KTB boundary events, since for instance Ir could have been outgassed from the magma, and original concentrations of only 0.05 ng.g−1 prior to outgassing are sufficient to account for the worldwide Ir excess mass at the KTB.