Analysis of information sources in references of the Wikipedia article "Azolla event" in English language version.
The Sr-Nd isotopic record is [...] indicative of a poorly mixed ocean and highly stratified water column with anoxic bottom waters. A stable, "fresh" water upper layer was likely a pervasive feature of the Eocene Arctic Ocean[permanent dead link] (full text of a similar article at doi:10.1029/2008PA001685)
The Sr-Nd isotopic record is [...] indicative of a poorly mixed ocean and highly stratified water column with anoxic bottom waters. A stable, "fresh" water upper layer was likely a pervasive feature of the Eocene Arctic Ocean[permanent dead link] (full text of a similar article at doi:10.1029/2008PA001685)