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Author

Ramananda Chakrabarti

Bio: Ramananda Chakrabarti is an academic researcher from Indian Institute of Science. The author has contributed to research in topics: Craton & Dharwar Craton. The author has an hindex of 19, co-authored 56 publications receiving 1235 citations. Previous affiliations of Ramananda Chakrabarti include University of Rochester & Harvard University.
Topics: Craton, Dharwar Craton, Basalt, Geology, Metasomatism


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors analyzed major, trace elements and Nd-Sr-Pb isotopes in Nyiragongo and Nyamuragira lavas including samples from 2002, 2003 and 2004 eruptions.

121 citations

Journal ArticleDOI
TL;DR: In this paper, a set of globally distributed and stratigraphically constrained chromites (FeMgCr2O4, n = 30) collected from various locations in Europe, Asia, Africa and South America were used to further constrain the isotope composition of the Earth's mantle Cr inventory and its possible variation during geological history.

117 citations

Journal ArticleDOI
TL;DR: In this paper, the trace element concentration patterns as well as Nd isotopic compositions of the clastic and non-clastic sediments of the Vindhyan Basin, from one of the type-localities of the SVBS stratigraphy in the Son valley, are vastly different from those of the Bundelkhand granite, which is the basement for these sediments, indicating that these granitic rocks were not a major source of sediments.

104 citations

Journal ArticleDOI
TL;DR: In this article, high-precision MC-ICPMS measurements of 14 meteorites, both primitive and differentiated, 5 lunar basalts and breccia samples, 5 terrestrial basalts, 1 dunite and 3 peridotites were reported.

88 citations

01 Mar 2010
TL;DR: In this article, high-precision MC-ICPMS measurements of 14 meteorites, both primitive and differentiated, 5 lunar basalts and breccia samples, 5 terrestrial basalts, 1 dunite and 3 peridotites were reported.
Abstract: We report high-precision MC-ICPMS measurements of 25Mg/24Mg and 26Mg/24Mg isotope ratios for 14 meteorites, both primitive and differentiated, 5 lunar basalts and breccia samples, 5 terrestrial basalts, 1 dunite and 3 peridotites. We estimate the δ26Mg value of the bulk silicate Earth (BSE) at − 0.54 ± 0.04 (2SE) w.r.t. DSM3. Carbonaceous and ordinary chondrites show an average δ26Mg of − 0.52 ± 0.04 (2SE), martian meteorites show a narrow range in δ26Mg with an average δ26Mg of − 0.57 ± 0.02 (2SE), average δ26Mg of pallasite olivines is − 0.54 ± 0.04 (2SE) whereas that of lunar samples, including ilmenite basalts, olivine basalt and one crystalline breccia is − 0.51 ± 0.03 (2SE). Our data demonstrate that the overall stable Mg isotopic composition of the inner Solar System (average δ25Mg = − 0.273, δ26Mg = − 0.535) is homogeneous to within ± 0.04‰ for 26Mg/24Mg. This value is indistinguishable from that of the BSE and lunar samples demonstrating that the Mg isotopic composition of the Earth–Moon system is chondritic. Accurate determination of the Mg isotopic composition of the rocky planets is important for Mg isotope studies of surface processes on Earth as well as for using Mg isotope data to understand evaporation and condensation effects in the solar nebula. Consistent with a recent report we find that clinopyroxenes have higher δ26Mg than co-existing olivines and orthopyroxenes in mantle peridotites, although the magnitude of this difference varies (0.08 to 0.2‰). Such small mineral fractionations along with differences between components in primitive meteorites (CAIs, chondrules, and matrix) preclude the resolution of mass-dependent fractionation differences smaller than about 0.05‰ between Solar System objects. We demonstrate that our results do not support the recent claims that: (i) the Earth–Moon system has a unique Mg isotope composition different from chondrites, or (ii) the higher δ26Mg values (up to 0.0) reported for chondrites, achondrites, terrestrial basalts and peridotites. To address the issue of inter-laboratory discrepancies on the Mg isotopic composition of silicate rocks, we have prepared 3 pure Mg standards with wide ranging δ26Mg (− 3.75 to − 0.69 with respect to DSM3) as well as a large volume of homogenized olivine from the San Carlos peridotite, which will be available to the scientific community, for future comparative studies.

83 citations


Cited by
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01 Jan 1980
TL;DR: In this article, the influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition and found that the variability of the relationship between the δ^(15)N values of animals and their diets is greater for different individuals raised on the same diet than for the same species raised on different diets.
Abstract: The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

5,548 citations

Book ChapterDOI
TL;DR: The composition of the primitive mantle derived by as mentioned in this paper shows that Earth was assembled from material that shows many of the same chemical fractionation processes as chondritic meteorites. But the stable isotope record excludes chondrite meteorites as the ‘building blocks’ of Earth.
Abstract: The composition of the primitive mantle derived here shows that Earth was assembled from material that shows many of the same chemical fractionation processes as chondritic meteorites. These processes occurred at the initial stage of the solar system formation, under conditions thought to be present in the solar nebula. But the stable isotope record excludes chondritic meteorites as the ‘building blocks’ of Earth. Meteorites formed in local environments separated from that part of the inner solar system where much of the material forming the terrestrial planets was sourced.

1,196 citations

Journal ArticleDOI
TL;DR: Paleosols (fossil soils) are preserved throughout the geologic record in depositional settings ranging from alluvial systems to between basalt flows as mentioned in this paper, and a variety of semi-quantitative and quantitative tools have been developed to examine past weathering and pedogenesis, and to reconstruct both paleoenvironmental and paleoclimatic conditions at the time that the paleosols formed.

766 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarized the occurrence of rare earth elements in the Earth's crust, their mineralogy, different types of deposits both on land and oceans from the standpoint of the new data with more examples from the Indian subcontinent.
Abstract: Rare earth elements (REE) include the lanthanide series elements (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) plus Sc and Y. Currently these metals have become very critical to several modern technologies ranging from cell phones and televisions to LED light bulbs and wind turbines. This article summarizes the occurrence of these metals in the Earth's crust, their mineralogy, different types of deposits both on land and oceans from the standpoint of the new data with more examples from the Indian subcontinent. In addition to their utility to understand the formation of the major Earth reservoirs, multi-faceted updates on the applications of REE in agriculture and medicine including new emerging ones are presented. Environmental hazards including human health issues due to REE mining and large-scale dumping of e-waste containing significant concentrations of REE are summarized. New strategies for the future supply of REE including recent developments in the extraction of REE from coal fired ash and recycling from e-waste are presented. Recent developments in individual REE separation technologies in both metallurgical and recycling operations have been highlighted. An outline of the analytical methods for their precise and accurate determinations required in all these studies, such as, X-ray fluorescence spectrometry (XRF), laser induced breakdown spectroscopy (LIBS), instrumental neutron activation analysis (INAA), inductively coupled plasma optical emission spectrometry (ICP-OES), glow discharge mass spectrometry (GD-MS), inductively coupled plasma mass spectrometry (including ICP-MS, ICP-TOF-MS, HR-ICP-MS with laser ablation as well as solution nebulization) and other instrumental techniques, in different types of materials are presented.

709 citations

Book
17 Nov 2014
TL;DR: Large igneous provinces (LIPs) are intraplate magmatic events, involving volumes of mainly mafic magma upwards of 100,000 km3, and often above 1 million km3 as discussed by the authors.
Abstract: Large igneous provinces (LIPs) are intraplate magmatic events, involving volumes of mainly mafic magma upwards of 100,000 km3, and often above 1 million km3. They are linked to continental break-up, global environmental catastrophes, regional uplift and a variety of ore deposit types. In this up-to-date, fascinating book, leading expert Richard E. Ernst explores all aspects of LIPs, beginning by introducing their definition and essential characteristics. Topics covered include continental and oceanic LIPs; their origins, structures, and geochemistry; geological and environmental effects; association with silicic, carbonatite and kimberlite magmatism; and analogues of LIPs in the Archean, and on other planets. The book concludes with an assessment of LIPs' influence on natural resources such as mineral deposits, petroleum and aquifers. This is a one-stop resource for researchers and graduate students in a wide range of disciplines, including tectonics, igneous petrology, geochemistry, geophysics, Earth history, and planetary geology, and for mining industry professionals.

525 citations