Sr, C, O isotopic data of well-preserved Campanian chalk from eastern Poland is shown.
Early-diagenetic calcite cementation did not alter the bulk isotopic composition.
δ13C and paleotemperature drop during the Campanian.
Belemnites were probably nectobenthic organisms.
Vital effects of up to 2‰ were recorded in δ13C and δ18O of benthic foraminifera.