Alladi Ramakrishnan Hall

Application of cosmogenic radionuclides $^{10}$Be and $^{26}$Al in the field of Earth sciences

Jitendra Pattanaik

IISER, Kolkata

Terrestrial cosmogenic radionuclides $^{10}$Be (T$_{1/2}$ - 1.387 Myrs) and
$^{26}$Al (T$_{1/2}$ - 0.7 Myrs) are being used for understanding various earth
surface processes. These nuclides are produced due to the interaction of
cosmic ray with the exposed atoms in the rock surface or in the atmosphere via
spallation reaction. The production rates of these nuclides are very low in
the Earth’s environment but the advancement in the measurement techniques and
apposite half life for dating various surfacial processes helped earth
scientist to use these nuclides as geochronometer and tracer. Most importantly
to establish an absolute time scale for the geological and paeloclimatic events
of the Quaternary period ($<$ 2.5 Myrs). The Quaternary period covers the last two
million years of the Earth’s history and it is significant because within this
time frame there were great climatic upheavals and humankind spread across the
world.

In this talk I will be discussing the following points: the production of
cosmogenic radionuclides in the earth’s environment, controlling parameters,
application of cosmogenic radionuclide as a radiometric clock and tracer in the
field of Earth Science, surface exposure dating, ongoing research work in the
Badrinath valley to establish the paleoglacial extent and timing.