Rajdeep Dasgupta

Assistant Professor
image of Dr. Rajdeep Dasgupta

Department of Earth Science, MS-126
Rice University
6100 Main Street
Houston, TX 77005
 
Phone:+1-713-348-2664 (office)
+1-713-348-2144 (lab)
Fax:+1-713-348-5214
E-mail: Rajdeep.Dasgupta@rice.edu
Office: 223 Keith-Wiess Geology Labs

Personal Web Page

Research Areas

Petrology, Experimental Petrology, Igneous Processes, Planetary Differentiation, Core-mantle exchange, Evolution of metallic cores in planetary bodies, Deep carbon cycle, Subduction zone processes and volatile cycling, Intraplate volcanism, Mantle heterogeneity, Magmatism in other terrestrial planets such as Mars, Venus, and Io

Deep Volatile Cycle and Mantle Melting

Exchange of volatiles such as carbon and hydrogen between different terrestrial reservoirs is an important step in the global carbon and water cycle, and has a key influence on the habitability of our planet. Though the terms "carbon cycle" and "water cycle" mostly refer to exchange of the respective volatiles between the near-surface reservoirs such as atmosphere and biosphere, oceans, and soils that operates on human time scales (short-term C and H2O cycle), the estimated total amount of carbon and/ or water stored in the Earth"s mantle, core, and crustal rocks is estimated to be significant. Thus, on time scales of millions of years, the exchange of C-O-H volatiles between deep Earth and near surface reservoirs (long-term C and H2O cycle) becomes important. C-O-H volatiles are of interest because of their effects on melting relationships, on transport of major to trace elements, and on the rheological and other physical properties of the mantle. CO2-H2O rich magmas play a significant role in releasing carbon and hydrogen from the mantle to the Earth"s surface, but the knowledge about the depth of formation or the compositions of these melts under mantle conditions is far from being complete.

Genesis of Ocean Island Basalts

Intra plate volcanic rocks from ocean islands (e.g., Hawaii, Iceland, Cape Verde, Reunion) provide a window to the Earth's deep interior. Their chemistry reflects variation in mantle sources and processes through both time and space. Integration of isotopic and trace element chemistry of ocean island basalts with their major element compositions is necessary to understand the physical nature of the mantle heterogeneities. I am interested in understanding the major element compositions of various flavors of ocean island basalts and what they tell us about the physical nature of their source compositions and the time-integrated history. I combine both experiments and natural observations to decipher possible nature of intraplate basalt source regions in general and those for ocean island basalts in particular.

Core-Mantle Differentiation and Exchange - Behavior and Influence of Light Elements

A new direction I am exploring in collaboration with Dave Walker and students Antonio Buono and Geoff Whelan at Columbia University, and Mike Walter and graduate student Oliver Lord at Bristol University is the study related to metallic cores of planetary bodies. I am interested in the process of core seggregation during early planetary differentiation and core-mantle exchange relevant to the present day planetary interiors. A particular emphasis is the role of various light elements in metal-silicate equilibria and in the composition and evolution of metallic cores.

Teaching Areas

Petrology, High temperature geochemistry, Materials characterization

 

Selected Publications

Abstracts

Dasgupta, R., Whelan, G., Buono, A., and Walker, D. "High-pressure melting relations in Fe-C-S systems: implications for metallic cores in planetary bodies." Geochimica et Cosmochimica Acta, 72 (2008) : A199.

Jackson, M. G. and Dasgupta, R. "Compositions of HIMU, EM1, and EM2 from global trends between radiogenic isotopes and major elements in ocean island basalts." EOS Trans. AGU, 89(53) (2008) : Fall Meet. Suppl. V41F-03.

Refereed Articles

Filiberto, J. & Dasgupta, R. (2011). Fe2+-Mg partitioning between olivine and basaltic melts: applications to genesis of olivine-phyric shergottites and conditions of melting in the Martian interior. Earth and Planetary Science Letters 304, 527-537. doi:10.1016/j.epsl.2011.02.029

Le Roux, V., Dasgupta, R. & Lee, C-T. A. (2011). Mineralogic heterogeneities in the Earth’s mantle: constraints from Mn, Co, Ni, and Zn partitioning during partial melting. Earth and Planetary Science Letters 307, 395-408. doi:10.1016/j.epsl.2011.05.014

Sanloup, C., van Westrenen, W., Dasgupta, R., Maynard-Casely, H. & Perrillat, J-P. (2011). Compressibility change in molten iron-rich metal at high pressure and models of core formation. Earth and Planetary Science Letters 306, 118-122. doi: 10.1016/j.epsl.2011.03.039

Tsuno, K. & Dasgupta, R. (2012). The effect of carbonates on near-solidus melting of pelite at 3 GPa: relative efficiency of H2O and CO2 subduction. Earth and Planetary Science Letters 319-320, 185-196. doi:10.1016/j.epsl.2011.12.007

Tsuno, K. & Dasgupta, R. (2011). Melting phase relation of nominally anhydrous, carbonated pelitic-eclogite at 2.5-3.0 GPa and deep cycling of sedimentary carbon. Contributions to Mineralogy and Petrology 161, 743-763. doi:10.1007/s00410-010-0560-9

Dasgupta, R., Buono, A., Whelan, G. & Walker, D. (2009). High-pressure melting relations in Fe-C-S systems: implications for formation, evolution, and structure of metallic cores in planetary bodies. Geochimica et Cosmochimica Acta 73, 6678-6691. doi:10.1016/j.gca.2009.08.001

Dasgupta, R., Hirschmann, M. M., McDonough, W. F., Spiegelman, M. & Withers, A. C. (2009). Trace element partitioning between garnet lherzolite and carbonatite at 6.6 and 8.6 GPa with applications to the geochemistry of the mantle and of mantle-derived melts. Chemical Geology 262, 57-77. doi:10.1016/j.chemgeo.2009.02.004

Dasgupta, R., Jackson, M. G. & Lee, C-T. A. (2010). Major element chemistry of ocean island basalts - conditions of mantle melting and heterogeneity of mantle source. Earth and Planetary Science Letters 289, 377-392. doi:10.1016/j.epsl.2009.11.027

Hirschmann, M. M. & Dasgupta, R. (2009). The H/C ratios of Earth’s near-surface and deep reservoirs, and consequences for deep Earth volatile cycles. Chemical Geology 262, 4-16. doi:10.1016/j.chemgeo.2009.02.008

Lord, O. T., Walter, M. J., Dasgupta, R., Walker, D. & Clark, S. M. (2009). Melting in the Fe-C system to 70 GPa. Earth and Planetary Science Letters 284, 157-167. doi:10.1016/j.epsl.2009.04.017

Dasgupta, R. & Hirschmann, M. M. (2007). A modified iterative sandwich method for determination of near-solidus partial melt compositions. II. Application to determination of near-solidus melt compositions of carbonated peridotite. Contributions to Mineralogy and Petrology 154, 647-661. doi:10.1007/s00410-007-0214-8

Dasgupta, R. & Hirschmann, M. M. (2007). Effect of variable carbonate concentration on the solidus of mantle peridotite. American Mineralogist 92, 370-379. doi:10.2138/am.2007.2201

Dasgupta, R. & Hirschmann, M. M. (2006). Melting in the Earth's deep upper mantle caused by carbon dioxide. Nature 440, 659-662. doi:10.1038/nature04612

Dasgupta, R. & Walker, D. (2008). Carbon solubility in core melts in a shallow magma ocean environment and distribution of carbon between the Earth's core and the mantle. Geochimica et Cosmochimica Acta 72, 4627-4641. doi:10.1016/j.gca.2008.06.023

Dasgupta, R., Hirschmann, M. M. & Dellas, N. (2005). The effect of bulk composition on the solidus of carbonated eclogite from partial melting experiments at 3 GPa. Contributions to Mineralogy and Petrology 149, 288-305. doi:10.1007/s00410-004-0649-0

Dasgupta, R., Hirschmann, M. M. & Smith, N. D. (2007). Partial melting experiments of peridotite + CO2 at 3 GPa and genesis of alkalic ocean island basalts. Journal of Petrology 48, 2093-2124. doi:10.1093/petrology/egm053

Dasgupta, R., Hirschmann, M. M. & Smith, N. D. (2007). Water follows carbon: CO2 incites deep silicate melting and dehydration beneath mid-ocean ridges. Geology 35, 135-138. doi:10.1130/G22856A.1

Dasgupta, R., Hirschmann, M. M. & Stalker, K. (2006). Immiscible transition from carbonate-rich to silicate-rich melts in the 3 GPa melting interval of eclogite+CO2 and genesis of silica-undersaturated ocean island lavas. Journal of Petrology 47, 647-671. doi:10.1093/petrology/egi088

Dasgupta, R., Hirschmann, M. M. & Withers, A. C. (2004). Deep global cycling of carbon constrained by the solidus of anhydrous, carbonated eclogite under upper mantle conditions. Earth and Planetary Science Letters 227, 73-85. doi:10.1016/j.epsl.2004.08.004

Hirschmann, M. M. & Dasgupta, R. (2007). A modified iterative sandwich method for determination of near-solidus partial melt compositions. I. Theoretical considerations. Contributions to Mineralogy and Petrology 154, 635-645. doi:10.1007/s00410-007-0213-9

Jackson, M. G. & Dasgupta, R. (2008). Compositions of HIMU, EM1, and EM2 from global trends between radiogenic isotopes and major elements in ocean island basalts. Earth and Planetary Science Letters 276, 175-186. doi:10.1016/j.epsl.2008.09.023

Presentations

Invited Talks

"Generation of alkalic intraplate basalts via partial melting of a carbonated mantle." AGU Fall Meeting, San Francisco, California, USA. (12/08/2011)

"Silicate melting in the Earth’s deep upper mantle caused by C-O-H volatiles." Goldschmidt Conference, Prague, Czech Republic. (08/15/2011) With Tsuno, K, Withers, A. C., Mallik, A.

"The depth and extent of volatile-fluxed mantle melting beneath ridges and plates." AGU Fall Meeting, San Francisco, California, USA. (12/07/2011)

"The influence of magma ocean processes on the present-day inventory of deep Earth carbon." CIDER Mini-Symposium, Berkeley, California, USA. (12/10/2011)

"Carbon Cycling in Subduction Zones – Implications for Mantle-Exosphere Exchange." MARGINS Planning Workshop, San Antonio, TX. (02/15/2010)

Dasgupta, R., Tsuno, K. & Gerbode, C. (2010). Melting in a volatile bearing, heterogeneous mantle and genesis of HIMU-EM ocean island basalts. Meeting of the Americas V42A-01.

Dasgupta, R. (2010). Petrology of deep storage, ingassing, and outgassing of terrestrial carbon. EOS Trans. AGU Fall Meet. Suppl. U23B-03.

Keynote Speaker

"Dichotomy of the Deep Earth Carbon and Water Cycle – A Review." SEDI, Santa Barbara, CA. (07/20/2010)

Lectures

"Earth's Deep Carbon Cycle." Packard Fellows Meeting, Monterey Bay, California, USA. (09/08/2011)

"From Core Formation to Crustal Recycling – Earth’s Deep Carbon Cycle Through Time." University of Texas at Austin, The Jackson School, Austin, Texas, USA. (09/29/2011)

"From Magma Ocean to Crustal Recycling - Earth's Deep Carbon Cycle through time." Boston University, Department of Earth Science, Boston, Massachusets, USA. (09/22/2011)

"Mantle Hybridization Through Melt-Rock Reaction and Genesis of Alkalic Ocean Island Basalts." University of Texas at Austin, The Jackson School, Austin, Texas, USA. (09/30/2011)

"Mantle hybridization through melt-rock reaction - composition and temperature of ocean island basalt source regions." Bayerisches Geoinstitut, Universität Bayreuth, Bayreuth, Germany. (10/25/2011)

Panelist

"Ocean Island Basalts and Mantle Heterogeneity." AGU Chapman Conference, Galapagos, Equador. (07/26/2011)

Seminar Speaker

"Mantle Heterogeneity Constrained by Chemistry of Ocean Island Basalts and Experimental Partial Melts." University of Chicago, Department of Geophysical Sciences, Chicago, IL. (04/30/2010)

Session Chair

"Volatiles in Mantle and Magma Processes." Goldschmidt Conference, Prague, Czech Republic. (08/17/2011)

Awards, Prizes, & Fellowships

F. W. Clarke Medal, The Geochemical Society (08/14/2011)

Packard Fellowship for Science and Engineering, The David and Lucile Packard Foundation (10/15/2010)

Positions Held

Adjunct Associate Research Scientist, LDEO, Columbia University. (07/08–present)

Visiting Scientist, Lunar and Planetary Institute, Universities Space Research Association. (03/08–present)