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Info-pedia / 29 Mar 2024

Info Pedia : Magnetic fossils

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Researchers at the CSIR-National Institute of Oceanography, located in Goa, have unearthed a colossal magneto fossil estimated to be around 50,000 years old in the Bay of Bengal. This discovery marks it as one of the most recently formed magneto fossils known to scientists.

About

       Magneto fossils are remnants of magnetic particles formed by magnetotactic bacteria, which orient themselves according to Earth's magnetic field.

       Initially identified in the 1960s, these bacteria produce small crystals rich in iron, such as magnetite or greigite, to aid in navigation amid fluctuating oxygen levels.

       Scientists utilized magnetic analysis and electron microscopy to scrutinize a sediment core extracted from the Bay of Bengal. This examination unveiled a variety of magnetofossils, including needle, spindle, bullet, and spearhead shapes, alongside conventional ones.

       The sediment's source was linked to river discharge, introducing reactive iron that, when combined with organic carbon under low-oxygen conditions, facilitated the proliferation of magnetotactic bacteria.

The presence of these fossils suggests prolonged suboxic conditions in the Bay of Bengal, conducive to bacterial growth.