Annotated record of the detailed examination of Mn deposits from DSDP Site 76, Leg 9 (Cores 76-1, 76A-1)

Site 76 was selected in order to core a thick sequence of sediments north of the Tuamotu ridge that had been crossed by Glomar Challenger justprior to the termination of Leg 8 in Tahiti. Two holes at this site continuously cored 27 meters of lower Pliocene to Recent phillipsitic clay and calcareous nannofossil ooze interbedded with calcareous turbidites. The drill bit was stopped by a silicified calcareous turbidite of Early Pliocene age.

选定76号站位，以在土阿莫土海岭（Tuamotu Ridge）北侧取心获取一套厚层沉积物序列——该区域恰为格洛玛·挑战者号（Glomar Challenger）在第8航次于塔希提岛终止前不久刚穿越过的海域。
本站位共布设2个钻孔，连续取心获得27米岩心，岩性为上新统下部至全新世的钙十字沸石黏土（phillipsitic clay）与钙质超微化石软泥（calcareous nannofossil ooze），二者与钙质浊积岩（calcareous turbidites）互层。
钻进过程中，钻头在上新世早期的硅化钙质浊积岩层位发生卡钻。