MAGNETOFOSSILS
– SCI & TECH
News:
Goa scientists find
50,000-year-old magnetic fossils in Bay of Bengal
What's
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:
●
Magnetofossils are fossilized remnants of magnetic particles formed by magnetotactic
bacteria, also known as magnetobacteria, found preserved within geological
records.
Characteristics
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.
Findings
of the Study:
●
Analysis of a three-meter-long sediment
core from the southwestern Bay of Bengal revealed primarily pale green silty
clays.
●
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.
●
Rivers
such as the Godavari, Mahanadi, Ganga-Brahmaputra, Cauvery, and Penner,
draining into the Bay of Bengal, played a significant role in magneto fossil
formation.
●
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.