Browsing Centre for Earth Sciences (CEaS) by Title
Now showing items 10-29 of 43
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A geochemical and Ca, Sr, Nd isotopic study of the mantle: case studies of Kimberlites, Ophiolites, Abyssal Peridotites, and Layered Igneous Complexes
The Earth’s mantle constitutes 67% of its mass and despite mantle convection, it is geochemically and isotopically heterogeneous as evident from the compositions of mantle derived basaltic melts. It is a dynamic system ... -
A geochemical and Ca-Sr-Nd isotopic study of glacial diamictites, loess and saprolites to understand crustal growth and silicate weathering
Earth is the only rocky planet in the Solar System with a compositionally evolved (felsic) continental crust. This incompatible element enriched layer is dominantly formed by extraction of melt from the upper mantle leading ... -
Geochemical and isotopic study of the Lonar and Dhala impact craters and jarosites from Kutch, India as analogues to understand planetary surface processes
Impact cratering and aqueous alteration are two important processes that have modified the Earth’s surface over time and better understanding of these processes on Earth allow us to understand the surface evolution of other ... -
A geochemical and Nd-Sr-Ca isotopic study of silicate weathering, crustal recycling and petrogenesis of carbonatites
Weathering of silicate rocks releases cations and anions which are transported to the oceans by rivers where calcium carbonate precipitates from the seawater. This process results in the net consumption of atmospheric ... -
A Geochemical and Sr, Ca, Mg, Li isotopic study of the Godavari River draining the Deccan basalts
Chemical weathering of continental silicate rocks releases cations and anions which are eventually precipitated as carbonates on the ocean floor. This entire process transfers carbon from the atmosphere to the oceans leading ... -
A geochemical, Nd-Sr, and stable Ca isotopic study of siliciclastic and chemical sedimentary rocks, volcanic tuffs, and authigenic glauconites from Proterozoic sedimentary basins of India
The Archean-Proterozoic transition is marked by globally synchronous changes in tectonothermal and climatic patterns along with development of widespread epicontinental seas, with extensive shelf-sedimentation. The Indian ... -
High Resolution Reconstruction of Rainfall Using Stable Isotopes in Growth Bands of Terrestrial Gastropod
(2017-10-25)Reconstruction studies of seasonal rainfall utilizing stable isotope based proxy approach suffer from the limitations of time resolutions. Conventional methods and archives limit the achievable resolution to annual scales. ... -
High Resolution Reconstruction of Rainfall Using Stable Isotopes in Growth Bands of Terrestrial Gastropod
(2017-10-25)Reconstruction studies of seasonal rainfall utilizing stable isotope based proxy approach suffer from the limitations of time resolutions. Conventional methods and archives limit the achievable resolution to annual scales. ... -
Improved laboratory and computational models for thermal core–mantle interaction
The Earth's magnetic field is generated by thermochemical convection within its fluid outer core. The near-stationary high-latitude magnetic flux concentrations in the present day field indicate that convective ... -
Investigating the geodynamics of the Indian plate using time-dependent mantle convection models
The northward migration of the Indian plate after breaking apart from Pangaea in Mesozoic followed by its collision with Eurasia during Cenozoic is a remarkable example of continental drift. Associated with this tectonic ... -
Investigating the role of mantle convection in affecting surface deformation and topography in the Indian plate and the India-Eurasia collision zone
The India-Eurasia collision zone has been a subject of various studies that have tried to explain the forces behind the high elevation and large scale continental deformation in this region. However, the relative contribution ... -
An investigation into the axial dipole field and mantle-induced heterogeneity in Earth
The Earth’s axial dipole field is generated by dynamo action in the planet’s outer core. It is understood from observations that the convection in the outer core is influenced by the lateral heterogeneity in the overlying ... -
An investigation of the role of buoyancy in magnetic polarity transitions in rapidly rotating dynamos
The dynamo operating within the Earth’s outer core generates a predominantly north-south dipolar magnetic field. Occasionally, the magnetic dipole axis flips its orientation and retains its approximate alignment with the ... -
The keeper of Chronicles - Investigating calcium carbonate archives using clumped thermometry
Calcium carbonates (CaCO3) are the most abundant mineral archive for reconstructing past climate owing to their tendency to register the environmental condition during their formation. From biogenically mediated carbonates ... -
Lab Experiment Documenting Growth of Microbes in an Extreme Condition
Bacterial population during 3.2 billion years of early earth was responsible for modifying the greenhouse gas concentration in the early earth. Here we studied the primitive facultative anaerobe E.coli K12, known to contain ... -
Late Cenozoic climate reconstruction from the Northern Indian Ocean using foraminiferal clumped isotope thermometry and stable isotope technique
The Late Cenozoic era (23.03 million years ago to the present) offers a critical time window to examine the role of greenhouse gases, notably CO2 (ranging between 910 ppm and 180 ppm), in the operation of Earth's system ... -
Mesoproterozoic Suturing Of Archean Crustal Blocks In Western Peninsular India : New Insights On India-Madagascar Correlations
(2017-08-21)The structural lineament mapping of southern India along withgeological, geochronological datasets help in redefining the Precambrian crustal blocks.The newly proposed Kumta and Mercara suture zones welding Archean crustal ... -
MHD Waves Driven by Small-scale Motion and Implications for the Earth's Core
(2018-05-22)Rotating convection in the Earth's core produces columnar vortices of radius ~10 km or less near the inner core boundary. Small-scale motions in the core can travel as Alfvén waves in the face of Ohmic diffusion, provided ... -
Modulation of Metal Fluxes and their Isotope Ratios in the Ganga (Hooghly) Estuary
This thesis aims at constraining the impact of estuarine processes on the net riverine fluxes of select metals and their isotopic composition to seawater. I studied the Ganga (Hooghly) River estuary, a monsoon-dominated ... -
On the spatio-temporal distribution of stable isotope ratios in the hydrological cycle over India and the Southern Ocean
The isotopic composition of water vapor and precipitation at continental and oceanic sites depends on factors such as: the geographical location of the sampling site, meteorological conditions at the moisture source ...