微化石のstratotypeとDSDP-IPODにより掘削された白亜紀のコア  [in Japanese] Cretaceous sediments recovered by the DSDP-IPOD project and their correlation with the stratotype sequences of planktonic micro fossil zones  [in Japanese]

Chronostratigraphic subdivision of DSDP-IPOD sediment cores of Cretaceous age has almost exclusively been made in reference to the European chronostratigraphic units which have widely been adopted and which have a relatively detailed sequence of numerical agestied to them. This attempt by DSDP-IPOD scientists at correlating deep-sea sediments with the shallow-marine and now land-exposed European sequences prompted intensive research to establish planktonic foraminiferal and calcareous nannoplankton zonations for the European standard sequences. To supplement biostratigraphic data deriving from meager planktonic microfossil taxa present in the European standard sequences, additional reference sequences have been established in the circum-Mediterranean region where deep-marine facies of the Cretaceous Tethys are exposed. Foraminiferal, nannofossil and paleomagnetic criteria which were pieced together from the standard sections in Europe and from the circum-Mediterranean reference sequences now enable a fairly reasonable correlation of 12 Cretaceous stages world-wide. Temporal and spatial distribution of DSDP-IPOD cores can now be summarized rather accurately in a global scale based on these established criteria.