PALEOMAGNETISM

Paleomagnetism provides great opportunity to work in the field of Paleomagnetism itself and apart from this there is a wide scope to work in other fields like Rock Magnetism, Anisotropy of Magnetic Susceptibility, Paleointensity, Environmental Magnetism and Archaeomagnetism.

Magnetostratigraphy of Kaladgi and Bhima Basin

  • To construct Magnetic Polarity Stratigraphy (MPS) for the Kaladgi and Bhima sedimentary Basin.
  • To identify different magnetic minerals contributing to the sedimentary rocks.
  • To develop MPS and correlate with standard Geomagnetic Polarity Time Scale to assess the age of the sedimentary strata of Kaladgi and Bhima sedimentary Basin.

Koyna Drill Core Research

The Earth magnetic field is the only surface trace of the working of the Earth’s core. Knowledge of its long-term variations in the strength of the mean dipole field over different regions is crucial for the understanding of the geodynamo and of the interactions at the core-mantle boundary.

Other volcanic provinces of the world have been explored using magnetic methods to deliver information on various aspects of flow dynamics apart from palaeomagnetism. The Deccan trap has been investigated since long over magnetostratigraphic aspects resulting into well constrained magnetic-chrons. However apart from these broad magnetic-chron and fundamental concepts on the magnetic minerals no further detailed work on the advanced topics like paleointensity, magnetic flow stratigraphy and anisotropy of magnetic susceptibility is available. These studies can deliver useful information on the Late Cretaceous geodynamo, flow dynamics, post magmatic deformation (amount of strain) and overall evolution of the Deccan traps volcanism. The attempt on core samples can produce one of the most systematic data on rock magnetism and magnetic fabrics facilitating an ideal repository for further studies on the discrete outcrop samples in the Deccan volcanic province. Several new concepts and ideas may arise from this data contributing to fundamental understanding on large igneous provinces and volcanism. Therefore it is a rare opportunity for the rock magnetists to work on such cores in any part of the world.

Well-constrained palaeomagnetic directions have already been derived from moderately steep +ve and -ve inclinations (~45-50°) in the Deccan Traps and this inclination is steep enough to distinguish normal from reversed magnetic polarity from the sign of the magnetic inclination (positive or negative) determined from samples drilled systematically in a vertical orientation along the axis of the core. This can be achieved if the core is properly logged and if it is possible to trace an arbitrary reference line all along axis of the core. Provided that these criteria are met, the Koyna core offers a great opportunity to better understand the likely duration of Deccan volcanism.

Paleomagnetism and AMS experimental work is under progress.

Paleomagnetic Investigations on mafic dykes around Dongargarh Supergroup

Oriented block samples were collected from mafic dykes of Dongar Supergroup. Rock magnetic properties were measured on the acquired specimens. Paleomagnetic experimental work is under progress.

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Figure: Thermoremanent curve for the Dongargarh mafic dyke showing the blocking temperature of Magnetite.

Paleomagnetism Laboratory

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Ongoing Projects:


S.No

Project title

Project Number and Sponsored by

1

Magnetostratigraphy of the Kaladgi and Bhima Basin and the mineral magnetics

MLP 6514-28(MV)

2

Palaeomagnetic Investigations across the one km long Koyna drill core

GAP708-28(MV)

3

Rock magnetic and Anisotropy of magnetic susceptibility (AMS) Studies of the Deccan trap Drill-Cores around Koyna Reservoir: Implications to flow stratigraphy and rock deformation

GAP723-28(MV)

4

Paleomagnetic Investigations of mafic dykes around Dongargarh Supergroup

INDEX:WP2.2

5

Integrated geological, petrological, geochemical, paleomagnetic and metallogeny in selected areas of southern, central and eastern Indian cratons

MLP6201-28(CM)


Staff:


S.No

Name

Designation

Specialization

1

Dr. M. Venkateshwarlu

Senior Scientist and Project Leader

Paleomagnetism

2

N. Ramesh Babu

T.O

Paleomagnetism