The Late Miocene‐Early Pliocene Biogenic Bloom: An Integrated Study in the Tasman Sea

The Late Miocene-Early Pliocene Biogenic Bloom (∼9–3.5 Ma) was a paleoceanographic phenomenon defined by anomalously high accumulations of biological components at multiple open ocean sites, especially in certain regions the Indian, and Pacific oceans. Its temporal spatial extent with available information leaves fundamental questions about driving forces responses unanswered. In this work, we focus on middle part (7.4–4.5 International Ocean Discovery Program Site U1506 Tasman Sea, where provide an integrated age model based orbital tuning Natural Gamma Radiation, benthic foraminiferal oxygen isotopes, calcareous nannofossil biostratigraphy. Benthic assemblages suggest changes deep water concentration seafloor nutrient supply during generally export productivity conditions. From 7.4 to 6.7 Ma, conditions were characterized episodic supply, perhaps related seasonal phytoplankton blooms. 4.5 regime shifted more stable interval eutrophic dysoxic Combined seismic data, regional change paleoceanography is inferred around from stronger well-oxygenated bottom currents weaker, oxygen-depleted currents. Our results support hypothesis that complex, multiphase driven currents, rather than single uniform period sustained sea surface productivity. Highly resolved studies are thus its understanding disentanglement local, regional, global imprints.