MAGNETOFOSSILS – SCI & TECH News: Goa scientists find 50,000-year-old magnetic fossils in Bay of Bengal


Goa scientists find
50,000-year-old magnetic fossils in Bay of Bengal


in the news?

In the depths of the Bay of Bengal,
researchers have unearthed a colossal magnetofossil embedded within a 50,000-year-old
sediment, marking it as one of the most recent discoveries of its kind.



Magnetofossils are fossilized remnants of magnetic particles formed by magnetotactic
bacteria, also known as magnetobacteria, found preserved within geological


of Magnetotactic Bacteria:

Magnetotactic bacteria are primarily prokaryotic organisms that align
themselves along the earth’s magnetic field.

Traditionally, these bacteria were thought
to navigate using the magnetic field
to reach locations with optimal oxygen levels.

They contain unique structures rich in
iron, resembling compasses, stored within small sacs.

These bacteria produce tiny crystals
composed of iron-rich minerals like
magnetite or greigite,
aiding them in navigating varying oxygen levels in
their aquatic habitats.


of the Study:

Analysis of a three-meter-long sediment
core from the southwestern Bay of Bengal revealed primarily pale green silty

Abundant benthic and planktonic foraminifera,
single-celled organisms with shells, were discovered near the sea bed and in
free-floating water.

Microscopy confirmed the presence of both conventional and giant magneto fossils
within the sediment sample.

The Bay of Bengal, particularly at depths
of 1,000-1,500 meters, exhibited notably low oxygen concentrations.

Fluctuations in monsoon activity were
detected through analysis of magnetic mineral particles from distinct
geological periods.

such as the Godavari, Mahanadi, Ganga-Brahmaputra, Cauvery, and Penner,
draining into the Bay of Bengal, played a significant role in magneto fossil

Nutrient-rich sediment transported by
these rivers, combined with reactive iron and organic carbon in suboxic
conditions, created a favorable environment for magnetotactic bacteria growth.

Freshwater discharge from rivers, along
with oceanographic processes like eddy formation, contributed to oxygen levels
uncommon in typical low-oxygen zones.

The presence of magnetofossils suggests
prolonged suboxic conditions in the Bay of Bengal, facilitating the thriving of
magnetotactic bacteria over an extended period.