(Table S1, S4) Campanian-Maastrichtian benthic foraminifera from ODP Hole 113-690C

• Main Authors: Koch, Mirjam C, Friedrich, Oliver
• Format: Dataset
• Language: English
• Published: PANGAEA 2012
• Subjects: 113-690C; AGE; Alabamina sp.; Allomorphina cf. navarroana; Allomorphina minuta; Allomorphina sp.; Allomorphina trochoides; Angulogavelinella sp.; Aragonia velascoensis; Arenobulimina preslii; Arenobulimina sp.; Astacolus cretaceus; Astacolus sp.; Ataxophragmium rimosum; Biedafranciszkina polonica; Bolivina incrassata; Bolivina sp.; Bolivina witwickae; Bolivinoides paleocenicus; Bulimina sp.; Buliminella cf. excavata; Chrysalogonium tenuistriatum; Cibicides cf. excavata; Cibicidoides bembix; Cibicidoides sp.; Cibicidoides velascoensis; Cibicidoides voltzianus; Counting >125 µm fraction; Cuneus minutus; Cuneus trigona; Dentalina sp.; Dentalina sulcata; DEPTH; sediment/rock; Dorothia oxycona; Dorothia pupa; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Ellipsodimorphina hrubieszowcensis; Ellipsodimorphina sp.; Ellipsodimorphina variabilis; Ellipsoidella gracillima; Ellipsoidella kugleri; Ellipsoidella pleurostomelloides; Ellipsoidella polonica; Ellipsoidella sp.; Ellipsoidella variabilis; Epistominella alata; Eponides beisseli; Antarc*; Antarctic; Antarctica
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.825712; https://doi.org/10.1594/PANGAEA.825712

During the latest Cretaceous cooling phase, a positive shift in benthic foraminiferal d18O values lasting about 1.5 Myr (71.5-70 Ma) can be observed at a global scale (Campanian-Maastrichtian Boundary Event, CMBE). This d18O excursion is interpreted as being influenced by a change in intermediate- to deep-water circulation or by temporal build-up of Antarctic ice sheets. Here we test whether benthic foraminiferal assemblages from a southern high-latitudinal site near Antarctica (ODP Site 690) are influenced by the CMBE. If the d18O transition reflects a change in intermediate- to deep-water circulation from low-latitude to high-latitude water masses, then this change would result in cooler temperatures, higher oxygen concentration, and possibly lower organic-matter flux at the seafloor, resulting in a major benthic foraminiferal assemblage change. If, however, the d18O transition was mainly triggered by ice formation, no considerable compositional difference in benthic foraminiferal assemblages would be expected. Our data show a separation of the studied succession into two parts with distinctly different benthic foraminiferal assemblages. Species dominating the older part (73.0-70.5 Ma) tolerate less bottom water oxygenation and are typical components of low-latitude assemblages. In contrast, the younger part (70.0-68.0 Ma) is characterized by species that indicate well-oxygenated bottom waters and species common in high-latitude assemblages. We interpret the observed change in benthic foraminiferal assemblages toward a well-oxygenated environment to reflect the onset of a shift from low-latitude toward high-latitude dominated intermediate- to deep-water sources. This implies that a change in oceanic circulation was at least a major component of the CMBE.