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1. Intramolecular hydrogen isotope exchange inside silicate melts – The effect of deuterium concentration

Author

Kueter, Nico, Cody, George D., Foustoukos, Dionysis I., and Mysen, Bjorn O.

Subjects
Volatiles, NMR spectroscopy, Silicate melt, Deep water cycle, Hydrogen isotopes, Geochemistry and Petrology, Geology
Abstract

Tracing the deep geological water cycle requires knowledge of the hydrogen isotope systematics between and within hydrous materials. For quenched hydrous alkali-silicate melts, hydrogen NMR reveals a distinct heterogeneity in the distribution of stable hydrogen isotopes (D, H) within the silicate tetrahedral network, where deuterons concentrate strongly in network regions that are associated with alkali cations. Previous hydrogen NMR studies performed in the sodium tetrasilicate system (Na2O x 4SiO2, NS4) with a 1:1 D2O/H2O ratio showed on average 1300 ‰ deuterium enrichment in the alkali-associated network, but the effect on varying bulk D2O/H2O ratios on this intramolecular isotope effect remained unconstrained. Experiments in the hydrous sodium tetrasilicate system with 8 wt% bulk water and varying bulk D2O/H2O ratios were performed at 1400 °C and 1.5 GPa. It is found that both hydrogen isotopes preferably partition into the silicate network that is associated with alkali ions. The partitioning is always stronger for the deuterated than for the protonated hydrous species. The relative enrichment of deuterium over protium in the alkali-associated network, i.e., the intramolecular isotope effect, correlates positively with the D2O/H2O bulk ratio of the hydrous NS4 system. Modeled for natural deuterium abundance (D/H near 1.56 × 10−4), a 1.4-fold (c. 340 ‰) deuterium enrichment in the alkali-associated silicate network is predicted. The partitioning model further predicts a positive correlation between the bulk water content of the silicate melt and the intramolecular deuterium partitioning into the alkali-associated silicate network. Such heterogeneities may explain the magnitude and direction of hydrogen isotope fractionation in hydrous silicate melts coexisting with silicate-saturated fluids. As such, this intramolecular isotope effect appears to be an effective mechanism for deuterium separation, particularly in hydrous magmatic settings, such as subduction zones., Chemical Geology, 610, ISSN:0009-2541, ISSN:1872-6836

Published
2022
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2. Additional file 1 of 29Si solid state NMR and Ti K-edge XAFS pre-edge spectroscopy reveal complex behavior of Ti in silicate melts

Author

Ackerson, Michael R., Cody, George D., and Mysen, Bjorn O.

Abstract

Additional file 1: Supplementary Figure S1. Ti XANES spectrum of an NS8 glass with 15 mol. % TiO2, compared with a spectrum from [6]Ti-bearing crystalline titanite (CaTiSiO5). The sharp white line peak in the titanite spectrum above the absorption edge is an indicator of the crystalline nature of the titanite. The broad edge feature in the Ti15NS8 spectrum suggests the material is amorphous. Supplementary Figure S2. Ti XANES spectrum of NS8 glasses with 10 mol % TiO2 synthesized from 1186, 1250, and 1580 °C. All glasses produced near-identical spectra, suggesting that there is no effect of dwell temperature on the solubility mechanism of Ti in NS8 glasses.

Published
2020
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3. The effects of atmospheric entry heating on organic matter in interplanetary dust particles

Author

Riebe, My E. I., Foustoukos, Dionysis I., Alexander, Conel M. O'D., Steele, Andrew, Cody, George D., Mysen, Bjorn, and Nittler, Larry R.

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

Interplanetary dust particles (IDPs) were likely major sources of extraterrestrial organics to the early Earth. However, IDPs experience heating to > 500 ${\deg}$C for up to several seconds during atmospheric entry. In this study, we aim to understand the effects of atmospheric entry heating on the dominant organic component in IDPs by conducting flash heating experiments (4 s to 400 {\deg}C, 600 {\deg}C, 800 {\deg}C, and 1000 {\deg}C) on insoluble organic matter (IOM) extracted from the meteorite Cold Bokkeveld (CM2). For each of the experimental charges, the bulk isotopic compositions of H, N, and C were analyzed using IRMS, the H isotopic heterogeneities (occurrence of hotspots) of the samples were measured by NanoSIMS, and the functional group chemistry and ordering of the IOM was evaluated using FTIR and Raman spectroscopy, respectively. IOM in particles heated to > 600 {\deg}C experienced loss of isotopically heavy, labile H and N groups, resulting in decreases in bulk ${\delta}$D, ${\delta}$15N, H/C and, upon heating > 800 {\deg}C, in N/C. The H heterogeneity was not greatly affected by flash heating to < 600 {\deg}C, although the hotspots tended to be less isotopically anomalous in the 600 {\deg}C sample than in the 400 {\deg}C sample. However, the hotspots all but disappeared in the 800 {\deg}C sample. Loss of C=O groups occurred at 800 {\deg}C. Based on the Raman G-band characteristics, the heating resulted in increased ordering of the polyaromatic component of the IOM. The data presented in this study show that all aspects of the composition of IOM in IDPs are affected by atmospheric entry heating. Modelling and temperature estimates from stepwise release of He has shown that most IDPs are heated to > 500{\deg}C (Love and Brownlee, 1991; Nier and Schlutter, 1993), hence, atmospheric entry heating is expected to have altered the organic matter in most IDPs., Comment: 31 pages, 6 figures. Submitted to Earth and Planetary Science Letters (EPSL)

Published
2020
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4. Supplementary Material from Protoenzymes: the case of hyperbranched polyesters

Author

Mamajanov, Irena and Cody, George D.

Subjects
macromolecular substances
Abstract

Enzymes are biopolymeric complexes that catalyse biochemical reactions and shape metabolic pathways. Enzymes usually work with small molecule cofactors that actively participate in reaction mechanisms and complex, usually globular, polymeric structures capable of specific substrate binding, encapsulation and orientation. Moreover, the globular structures of enzymes possess cavities with modulated microenvironments, facilitating the progression of reaction(s). The globular structure is assured by long folded protein or RNA strands. Synthesis of such elaborate complexes has proven difficult under prebiotically plausible conditions. We explore here that catalysis may have been performed by alternative polymeric structures, namely, hyperbranched polymers. Hyperbranched polymers are relatively complex structures that can be synthesized under prebiotically plausible conditions; their globular structure is assured by virtue of their architecture rather than folding. In this study, we probe the ability of tertiary amine-bearing hyperbranched polyesters to form hydrophobic pockets as a reaction promoting medium for the Kemp elimination reaction. Our results show that polyesters form upon reaction between glycerol, triethanolamine and organic acid containing hydrophobic groups, adipic and methylsuccinic acid, are capable of increasing the rate of Kemp elimination by a factor of up to three over monomeric triethanolamine.

Published
2017
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5. Isotope ratios of H, C, and O in CO₂ and H₂O of the martian atmosphere

Author

Webster, Chris R, Mahaffy, Paul R, Flesch, Gregory J, Niles, Paul B, Jones, John H, Leshin, Laurie A, Atreya, Sushil K, Stern, Jennifer C, Christensen, Lance E, Owen, Tobias, Franz, Heather, Pepin, Robert O, Steele, Andrew and the MSL Science Team, Achilles, Cherie, Agard, Christophe, Alves Verdasca, José Alexandre, Anderson, Robert, Anderson, Ryan, Archer, Doug, Armiens-Aparicio, Carlos, Arvidson, Ray, Atlaskin, Evgeny, Aubrey, Andrew, Baker, Burt, Baker, Michael, Balic-Zunic, Tonci, Baratoux, David, Baroukh, Julien, Barraclough, Bruce, Bean, Keri, Beegle, Luther, Behar, Alberto, Bell, James, Bender, Steve, Benna, Mehdi, Bentz, Jennifer, Berger, Gilles, Berger, Jeff, Berman, Daniel, Bish, David, Blake, David F, Blanco Avalos, Juan J, Blaney, Diana, Blank, Jen, Blau, Hannah, Bleacher, Lora, Boehm, Eckart, Botta, Oliver, Böttcher, Stephan, Boucher, Thomas, Bower, Hannah, Boyd, Nick, Boynton, Bill, Breves, Elly, Bridges, John, Bridges, Nathan, Brinckerhoff, William, Brinza, David, Bristow, Thomas, Brunet, Claude, Brunner, Anna, Brunner, Will, Buch, Arnaud, Bullock, Mark, Burmeister, Sönke, Cabane, Michel, Calef, Fred, Cameron, James, Campbell, John, Cantor, Bruce, Caplinger, Michael, Caride Rodríguez, Javier, Carmosino, Marco, Carrasco Blázquez, Isaías, Charpentier, Antoine, Chipera, Steve, Choi, David, Clark, Benton, Clegg, Sam, Cleghorn, Timothy, Cloutis, Ed, Cody, George, Coll, Patrice, Conrad, Pamela, Coscia, David, Cousin, Agnès, Cremers, David, Crisp, Joy, Cros, Alain, Cucinotta, Frank, d'Uston, Claude, Davis, Scott, Day, Mackenzie, de la Torre Juarez, Manuel, DeFlores, Lauren, DeLapp, Dorothea, DeMarines, Julia, DesMarais, David, Dietrich, William, Dingler, Robert, Donny, Christophe, Downs, Bob, Drake, Darrell, Dromart, Gilles, Dupont, Audrey, Duston, Brian, Dworkin, Jason, Dyar, M Darby, Edgar, Lauren, Edgett, Kenneth, Edwards, Christopher, Edwards, Laurence, Ehlmann, Bethany, Ehresmann, Bent, Eigenbrode, Jen, Elliott, Beverley, Elliott, Harvey, Ewing, Ryan, Fabre, Cécile, Fairén, Alberto, Farley, Ken, Farmer, Jack, Fassett, Caleb, Favot, Laurent, Fay, Donald, Fedosov, Fedor, Feldman, Jason, Feldman, Sabrina, Fisk, Marty, Fitzgibbon, Mike, Floyd, Melissa, Flückiger, Lorenzo, Forni, Olivier, Fraeman, Abby, Francis, Raymond, François, Pascaline, Freissinet, Caroline, French, Katherine Louise, Frydenvang, Jens, Gaboriaud, Alain, Gailhanou, Marc, Garvin, James, Gasnault, Olivier, Geffroy, Claude, Gellert, Ralf, Genzer, Maria, Glavin, Daniel, Godber, Austin, Goesmann, Fred, Goetz, Walter, Golovin, Dmitry, Gómez Gómez, Felipe, Gómez-Elvira, Javier, Gondet, Brigitte, Gordon, Suzanne, Gorevan, Stephen, Grant, John, Griffes, Jennifer, Grinspoon, David, Grotzinger, John, Guillemot, Philippe, Guo, Jingnan, Gupta, Sanjeev, Guzewich, Scott, Haberle, Robert, Halleaux, Douglas, Hallet, Bernard, Hamilton, Vicky, Hardgrove, Craig, Harker, David, Harpold, Daniel, Harri, Ari-Matti, Harshman, Karl, Hassler, Donald, Haukka, Harri, Hayes, Alex, Herkenhoff, Ken, Herrera, Paul, Hettrich, Sebastian, Heydari, Ezat, Hipkin, Victoria, Hoehler, Tori, Hollingsworth, Jeff, Hudgins, Judy, Huntress, Wesley, Hurowitz, Joel, Hviid, Stubbe, Iagnemma, Karl, Indyk, Steve, Israël, Guy, Jackson, Ryan, Jacob, Samantha, Jakosky, Bruce, Jensen, Elsa, Jensen, Jaqueline Kløvgaard, Johnson, Jeffrey, Johnson, Micah, Johnstone, Steve, Jones, Andrea, Joseph, Jonathan, Jun, Insoo, Kah, Linda, Kahanpää, Henrik, Kahre, Melinda, Karpushkina, Natalya, Kasprzak, Wayne, Kauhanen, Janne, Keely, Leslie, Kemppinen, Osku, Keymeulen, Didier, Kim, Myung-Hee, Kinch, Kjartan, King, Penny, Kirkland, Laurel, Kocurek, Gary, Koefoed, Asmus, Köhler, Jan, Kortmann, Onno, Kozyrev, Alexander, Krezoski, Jill, Krysak, Daniel, Kuzmin, Ruslan, Lacour, Jean Luc, Lafaille, Vivian, Langevin, Yves, Lanza, Nina, Lasue, Jeremie, Le Mouélic, Stéphane, Lee, Ella Mae, Lee, Qiu-Mei, Lees, David, Lefavor, Matthew, Lemmon, Mark, Lepinette Malvitte, Alain, Léveillé, Richard, Lewin-Carpintier, Éric, Lewis, Kevin, Li, Shuai, Lipkaman, Leslie, Little, Cynthia, Litvak, Maxim, Lorigny, Eric, Lugmair, Guenter, Lundberg, Angela, Lyness, Eric, Madsen, Morten, Maki, Justin, Malakhov, Alexey, Malespin, Charles, Malin, Michael, Mangold, Nicolas, Manhes, Gérard, Manning, Heidi, Marchand, Geneviève, Marín Jiménez, Mercedes, Martín García, César, Martin, Dave, Martin, Mildred, Martínez-Frías, Jesús, Martín-Soler, Javier, Martín-Torres, F Javier, Mauchien, Patrick, Maurice, Sylvestre, McAdam, Amy, McCartney, Elaina, McConnochie, Timothy, McCullough, Emily, McEwan, Ian, McKay, Christopher, McLennan, Scott, McNair, Sean, Melikechi, Noureddine, Meslin, Pierre-Yves, Meyer, Michael, Mezzacappa, Alissa, Miller, Hayden, Miller, Kristen, Milliken, Ralph, Ming, Douglas, Minitti, Michelle, Mischna, Michael, Mitrofanov, Igor, Moersch, Jeff, Mokrousov, Maxim, Molina Jurado, Antonio, Moores, John, Mora-Sotomayor, Luis, Morookian, John Michael, Morris, Richard, Morrison, Shaunna, Mueller-Mellin, Reinhold, Muller, Jan-Peter, Muñoz Caro, Guillermo, Nachon, Marion, Navarro López, Sara, Navarro-González, Rafael, Nealson, Kenneth, Nefian, Ara, Nelson, Tony, Newcombe, Megan, Newman, Claire, Newsom, Horton, Nikiforov, Sergey, Nixon, Brian, Noe Dobrea, Eldar, Nolan, Thomas, Oehler, Dorothy, Ollila, Ann, Olson, Timothy, de Pablo Hernández, Miguel Ángel, Paillet, Alexis, Pallier, Etienne, Palucis, Marisa, Parker, Timothy, Parot, Yann, Patel, Kiran, Paton, Mark, Paulsen, Gale, Pavlov, Alex, Pavri, Betina, Peinado-González, Verónica, Peret, Laurent, Perez, Rene, Perrett, Glynis, Peterson, Joe, Pilorget, Cedric, Pinet, Patrick, Pla-García, Jorge, Plante, Ianik, Poitrasson, Franck, Polkko, Jouni, Popa, Radu, Posiolova, Liliya, Posner, Arik, Pradler, Irina, Prats, Benito, Prokhorov, Vasily, Purdy, Sharon Wilson, Raaen, Eric, Radziemski, Leon, Rafkin, Scot, Ramos, Miguel, Rampe, Elizabeth, Raulin, François, Ravine, Michael, Reitz, Günther, Rennó, Nilton, Rice, Melissa, Richardson, Mark, Robert, François, Robertson, Kevin, Rodriguez Manfredi, José Antonio, Romeral-Planelló, Julio J, Rowland, Scott, Rubin, David, Saccoccio, Muriel, Salamon, Andrew, Sandoval, Jennifer, Sanin, Anton, Sans Fuentes, Sara Alejandra, Saper, Lee, Sarrazin, Philippe, Sautter, Violaine, Savijärvi, Hannu, Schieber, Juergen, Schmidt, Mariek, Schmidt, Walter, Scholes, Daniel, Schoppers, Marcel, Schröder, Susanne, Schwenzer, Susanne, Sebastian Martinez, Eduardo, Sengstacken, Aaron, Shterts, Ruslan, Siebach, Kirsten, Siili, Tero, Simmonds, Jeff, Sirven, Jean-Baptiste, Slavney, Susie, Sletten, Ronald, Smith, Michael, Sobrón Sánchez, Pablo, Spanovich, Nicole, Spray, John, Squyres, Steven, Stack, Katie, Stalport, Fabien, Stein, Thomas, Stewart, Noel, Stipp, Susan Louise Svane, Stoiber, Kevin, Stolper, Ed, Sucharski, Bob, Sullivan, Rob, Summons, Roger, Sumner, Dawn, Sun, Vivian, Supulver, Kimberley, Sutter, Brad, Szopa, Cyril, Tan, Florence, Tate, Christopher, Teinturier, Samuel, ten Kate, Inge, Thomas, Peter, Thompson, Lucy, Tokar, Robert, Toplis, Mike, Torres Redondo, Josefina, Trainer, Melissa, Treiman, Allan, Tretyakov, Vladislav, Urqui-O'Callaghan, Roser, Van Beek, Jason, Van Beek, Tessa, VanBommel, Scott, Vaniman, David, Varenikov, Alexey, Vasavada, Ashwin, Vasconcelos, Paulo, Vicenzi, Edward, Vostrukhin, Andrey, Voytek, Mary, Wadhwa, Meenakshi, Ward, Jennifer, Weigle, Eddie, Wellington, Danika, Westall, Frances, Wiens, Roger Craig, Wilhelm, Mary Beth, Williams, Amy, Williams, Joshua, Williams, Rebecca, Williams, Richard B, Wilson, Mike, Wimmer-Schweingruber, Robert, Wolff, Mike, Wong, Mike, Wray, James, Wu, Megan, Yana, Charles, Yen, Albert, Yingst, Aileen, Zeitlin, Cary, Zimdar, Robert, and Zorzano Mier, María-Paz

Subjects
isotope ratios, MSL-Radiation, Mars
Published
2013

6. Research article - Comet 81P/Wild 2 under a microscope

Author

Brownlee, Don, Tsou, Peter, Aleon, Jerome, Alexander, Conel M. O'D., Araki, Tohru, Bajt, Sasa, Baratta, Giuseppe A., Bastien, Ron, Bland, Phil, Bleuet, Pierre, Borg, Janet, Bradley, John P., Brearley, Adrian, Brenker, F., Brennan, Sean, Bridges, John C., Browning, Nigel D., Brucato, John R., Bullock, E., Burchell, Mark J., Busemann, Henner, Butterworth, Anna, Chaussidon, Marc, Cheuvront, Allan, Chi, Miaofang, Cintala, Mark J., Clark, B. C., Clemett, Simon J., Cody, George, Colangeli, Luigi, Cooper, George, Cordier, Patrick, Daghlian, C., Dai, Zurong, D'Hendecourt, Louis, Djouadi, Zahia, Dominguez, Gerardo, Duxbury, Tom, Dworkin, Jason P., Ebel, Denton S., Economou, Thanasis E., Fakra, Sirine, Fairey, Sam A. J., Fallon, Stewart, Ferrini, Gianluca, Ferroir, T., Fleckenstein, Holger, Floss, Christine, Flynn, George, Franchi, Ian A., Fries, Marc, Gainsforth, Z., Gallien, J. -P., Genge, Matt, Gilles, Mary K., Gillet, Philipe, Gilmour, Jamie, Glavin, Daniel P., Gounelle, Matthieu, Grady, Monica M., Graham, Giles A., Grant, P. G., Green, Simon F., Grossemy, Faustine, Grossman, Lawrence, Grossman, Jeffrey N., Guan, Yunbin, Hagiya, Kenji, Harvey, Ralph, Heck, Philipp, Herzog, Gregory F., Hoppe, Peter, Hoerz, Friedrich, Huth, Joachim, Hutcheon, Ian D., Ignatyev, Konstantin, Ishii, Hope, Ito, Motoo, Jacob, Damien, Jacobsen, Chris, Jacobsen, Stein, Jones, Steven, Joswiak, David, Jurewicz, Amy, Kearsley, Anton T., Keller, Lindsay P., Khodja, H., Kilcoyne, A. L. David, Kissel, Jochen, Krot, Alexander, Langenhorst, Falko, Lanzirotti, Antonio, Le, Loan, Leshin, Laurie A., Leitner, J., Lemelle, L., Leroux, Hugues, Liu, Ming-Chang, Luening, K., Lyon, Ian, MacPherson, Glen, Marcus, Matthew A., Marhas, Kuljeet, Marty, Bernard, Matrajt, Graciela, McKeegan, Kevin, Meibom, Anders, Mennella, Vito, Messenger, Keiko, Messenger, Scott, Mikouchi, Takashi, Mostefaoui, Smail, Nakamura, Tomoki, Nakano, T., Newville, M., Nittler, Larry R., Ohnishi, Ichiro, Ohsumi, Kazumasa, Okudaira, Kyoko, Papanastassiou, Dimitri A., Palma, Russ, Palumbo, Maria E., Pepin, Robert O., Perkins, David, Perronnet, Murielle, Pianetta, P., Rao, William, Rietmeijer, Frans J. M., Robert, Francois, Rost, D., Rotundi, Alessandra, Ryan, Robert, Sandford, Scott A., Schwandt, Craig S., See, Thomas H., Schlutter, Dennis, Sheffield-Parker, J., Simionovici, Alexandre, Simon, Steven, Sitnitsky, I., Snead, Christopher J., Spencer, Maegan K., Stadermann, Frank J., Steele, Andrew, Stephan, Thomas, Stroud, Rhonda, Susini, Jean, Sutton, S. R., Suzuki, Y., Taheri, Mitra, Taylor, Susan, Teslich, Nick, Tomeoka, Kazu, Tomioka, Naotaka, Toppani, Alice, Trigo-Rodriguez, Josep M., Troadec, David, Tsuchiyama, Akira, Tuzzolino, Anthony J., Tyliszczak, Tolek, Uesugi, K., Velbel, Michael, Vellenga, Joe, Vicenzi, E., Vincze, L., Warren, Jack, Weber, Iris, Weisberg, Mike, Westphal, Andrew J., Wirick, Sue, Wooden, Diane, Wopenka, Brigitte, Wozniakiewicz, Penelope, Wright, Ian, Yabuta, Hikaru, Yano, Hajime, Young, Edward D., Zare, Richard N., Zega, Thomas, Ziegler, Karen, Zimmerman, Laurent, Zinner, Ernst, and Zolensky, Michael

Subjects
Grains, Origin, Solar Nebula, Physics::Space Physics, Crystalline Silicates, P/Wild 2, Astrophysics::Solar and Stellar Astrophysics, Kuiper Belt, Astrophysics::Earth and Planetary Astrophysics, Mineralogy, Refractory Inclusions, Nucleus
Abstract

The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.

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