Magnetic properties of early Pliocene sediments from IODP Site U1467 (Maldives platform) reveal changes in the monsoon system

• Published in: Palaeogeography, palaeoclimatology, palaeoecology Vol. 533; p. 109283
• Main Authors: Lanci, Luca, Zanella, Elena, Jovane, Luigi, Galeotti, Simone, Alonso-García, Montserrat, Alvarez-Zarikian, Carlos A., Bejugam, Nagender Nath, Betzler, Christian, Bialik, Or M., Blättler, Clara L., Eberli, Gregor P., Guo, Junhua Adam, Haffen, Sébastien, Horozal, Senay, Inoue, Mayuri, Kroon, Dick, Laya, Juan Carlos, Mee, Anna Ling Hui, Lüdmann, Thomas, Nakakuni, Masatoshi, Niino, Kaoru, Petruny, Loren M., Pratiwi, Santi D., Reijmer, John J.G., Reolid, Jesús, Slagle, Angela L., Sloss, Craig R., Su, Xiang, Swart, Peter K., Wright, James D., Yao, Zhengquan, Young, Jeremy R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2019
• Subjects: Anisotropy of isothermal remanent magnetization; Currents strength; Monsoon; Paleomagnetism; Pliocene magnetic stratigraphy; Monsoon; Currents strength; Paleomagnetism; Pliocene magnetic stratigraphy; Anisotropy of isothermal remanent magnetization
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/j.palaeo.2019.109283

We report a study of the magnetic stratigraphy and the anisotropy of isothermal remanent magnetization of Pliocene sediments from International Ocean Discovery Program (IODP) Site U1467 drilled in the Maldives platform (Indian Ocean) during Exp. 359. Magnetic stratigraphy gives a precise record of geomagnetic reversals of the early Pliocene from approximately 5.3 Ma to 3.1 Ma providing a detailed age model in an interval where the biostratigraphic record is scarce. We use the anisotropy of isothermal remanent magnetization (AIRM) to investigate the statistical orientation of fine magnetic particles and provide data on the strength and direction of bottom currents during the early Pliocene. The strength of bottom currents recorded by the AIRM, shows a prominent increase at the top of Chron C3n.1n (about 4.2 Ma), and the current direction (NE - SW) is consistent with that of modern instrumental measurements. Since bottom currents in the Maldives are driven by the monsoon, we speculate that the 4.2 Ma increase of bottom currents could mark the onset of the present-day setting, probably related to the coeval uplift phase of the Himalayan plateau. [Display omitted] •Magneto-stratigraphic age model of Pliocene sediments from Site U1467.•Record of bottom currents from anisotropy of isothermal remanent magnetization.•Monsoon-related bottom currents increase at about 4.2 Ma.•Bottom currents increase is coeval with Late Pliocene phase of Himalayan uplift.