EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

The response of benthic foraminifera to the late Miocene-early Pliocene Biogenic Bloom: the record from Southeast Atlantic Ocean (ODP Site 1085)

Maria Elena Gastaldello1,2, Claudia Agnini1, Thomas Westerhold3, Edoardo Dallanave4, and Laia Alegret2
Maria Elena Gastaldello et al.
  • 1Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy (
  • 2Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Zaragoza, Spain
  • 3MARUM - Center for Marine Environmental Sciences, University of Bremen, Germany
  • 4Deparment of Geosciences, University of Bremen, Germany

The late Miocene-early Pliocene Biogenic Bloom was a significant event defined by the anomalously high marine biological productivity documented in the Indian, Pacific, and Atlantic Oceans; but its causes and consequences at different paleogeographical settings are not yet fully understood. Previous records from Ocean Drilling Program (ODP) Site 1085 (Cape Basin, Southeast Atlantic Ocean) indicate enhanced biological productivity between 7 and 4 Ma, as supported by increased linear sedimentation rates, benthic foraminiferal accumulation rates, and increased total organic carbon mass accumulation rates (Diester-Haass et al., 2002; 2004). To look into the paleoenvironmental consequences of the Biogenic Bloom, we investigated the benthic foraminiferal turnover at this site. Results were integrated with an age model based on a bio-astrocyclostratigraphic tuning and low-resolution carbon and oxygen stable isotope records on benthic foraminifera (i.e. Cibicidoides mundulus) across an interval spanning from the Tortonian (late Miocene) to the Zanclean (early Pliocene). Quantitative analyses of the assemblages and statistical analyses point to increased food supply to the seafloor. The proliferation of phytodetritus exploiting taxa such as Alabamina weddellensis and Epistominella exigua point to an episodic nutrient supply related to seasonal phytoplankton blooms during the Biogenic Bloom.


Diester-Haass, L., Meyers, P. A., & Vidal, L. (2002). The late Miocene onset of high productivity in the Benguela Current upwelling system as part of a global pattern. Marine Geology, 180(1-4), 87-103.

Diester-Haass, L., Meyers, P. A., & Bickert, T. (2004). Carbonate crash and biogenic bloom in the late Miocene: Evidence from ODP Sites 1085, 1086, and 1087 in the Cape Basin, southeast Atlantic Ocean. Paleoceanography, 19(1).


University of Padova DOR grant, CARIPARO Foundation Ph.D. scholarship.

Spanish Ministry of Economy and Competitiveness and FEDER funds (PID2019-105537RB-I00).

How to cite: Gastaldello, M. E., Agnini, C., Westerhold, T., Dallanave, E., and Alegret, L.: The response of benthic foraminifera to the late Miocene-early Pliocene Biogenic Bloom: the record from Southeast Atlantic Ocean (ODP Site 1085), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2260,, 2022.