Late Pliocene and early Pleistocene rock-magnetic record of IODP Site 306-U1314

• Main Authors: Sato, Masahiko, Makio, Masato, Hayashi, T, Ohno, Masao
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: 306-U1314; AGE; COMPCORE; Composite Core; DEPTH; sediment/rock; Exp306; High-coerecivity component; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Isothermal Remanent Magnetization; intensity; mean of gradient; median of gradient; mode of gradient; Joides Resolution; Low-coerecivity component; North Atlantic; North Atlantic Climate 2; Residual; New Rock; Iceland; NADW; Nordic Seas; North Atlantic Deep Water
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.848329; https://doi.org/10.1594/PANGAEA.848329

Knowledge of the evolution of North Atlantic Deep Water (NADW) is key to understanding the past evolution of the climatic system. We developed a new rock-magnetic method to determine the constituent magnetic minerals of sediments and report on the evolution of NADW during 2.2-2.9 Ma. We measured isothermal remanence acquisition curves of North Atlantic deep-sea sediments drilled at the Gardar Drift and decomposed the first derivatives of these curves into high-coercivity and low-coercivity components. Residuals of the decomposition were sufficiently small throughout the study interval, confirming that the Gardar Drift sediments represent a mixing of the two end-members. Fractional changes of the high-coercivity component represent variation of the Iceland-Scotland Overflow Water, a branch of NADW formed at the Nordic Seas. The high-coercivity component increased significantly during an interglacial period just after ~2.68 Ma, which suggests that NADW formation in the Nordic Seas abruptly intensified at this time.