Dr Guil Mallmann

Following completion of his PhD (2009) and subsequent postdoctoral research at ANU, Guil was awarded a FAPESP fellowship (2010) to pioneer a research program in experimental petrology at the University of São Paulo, Brazil. He returned to Australia in 2014 to lecture mineralogy and igneous-metamorphic petrology at the University of Queensland. Since 2016, Guil is an ARC DECRA Fellow at the Research School of Earth Sciences studying the ‘Redox Evolution of Basaltic Magmas’.


Ph.D. Experimental Petrology, ANU, 2009
M.Sc. Geochemistry, UFRGS, 2005
B.Sc. Geology, UFRGS, 2002

Research interests

Guil's research involves the use of experimental apparatuses to simulate the high temperature and pressure conditions of planetary interiors with the aim of understanding fundamental petrological and geochemical processes. He is also interested in novel applications of micro-analytical techniques and synchrotron light in the characterization of natural and synthetic materials. His current research projects are focused on trace element partitioning, element speciation in magmatic systems, oxidation state of planetary interiors, basalt petrogenesis, highly siderophile elements, and core-mantle-crust differentiation.

Areas of active research

  • Experimental petrology and geochemistry
  • Micro-analysis and micro-spectroscopy
  • Trace element speciation and partitioning in magmatic systems
  • Basalt petrogenesis
  • Oxidation state of planetary interiors
  • Core-mantle-crust differentiation

Major research grants

This project aims to quantify the changes in redox state (i.e. reduction and oxidation of chemicals) experienced by various types of basaltic magmas on their way to the surface, and assess the extent to which basaltic magmas can be used to infer redox conditions of their mantle sources. The redox state of the Earth’s mantle controls the valency of elements such as iron and the speciation of volatiles (e.g. hydrogen, carbon and sulphur) that degas from volcanoes and ultimately make up the atmosphere. The outcomes of this project may help us to better model the transport of metals in magmas and predict ore deposits, and assess the nature and relative contributions of volatiles that degas from volcanoes over the Earth’s geological history.
This project aims to investigate experimentally the geochemical behaviour of the highly siderophile elements (HSE), particularly concerning the effect of intensive variables such as temperature, pressure and oxygen fugacity on the partitioning of these elements between metal, minerals and silicate melt. Because of their strong affinity to metallic phases, HSEs provide unique insights into planetary accretion and differentiation. For instance, the absolute and relative abundances of siderophile elements can be used to identify the building blocks of terrestrial planets, trace core-mantle differentiation processes and the chemical interactions between these two reservoirs, as well as the late accretion histories of diverse planetary bodies like the Earth, Moon and Mars.

Student supervision

2017–            Mr Peteris Rozenbaks; Redox evolution of ocean island basaltic magmas (MSc, Australian National University, Supervisor)
2014 –2018    Ms Jacqui Wong; Trace element and oxygen isotope geochemistry of east Australian sapphires: Regional petrogenesis and tectonic implications (PhD, University of Queensland, Associate supervisor)
2014 –2018   Ms Tracey Crossingham; Temporal and petrogenetic constraints on age-progressive volcanism in eastern Australia (PhD, University of Queensland, Associate supervisor)
2016 – 2016  Mr Victor Cruz; Experimental study of the partitioning of phosphorus between olivine and basaltic magmas (Honors, University of Sao Paulo, Associate Supervisor)
2012 – 2013  Mr Adolfo Silva; The effect of oxygen fugacity on the partitioning of trace elements between rutile and magma: An experimental study (Honors, University of Sao Paulo, Principal supervisor)


PDF reprints can be accessed via ResearchGate

Publication metrics can be seen on Google Scholar

Journal papers

[25]   Crossingham T.J., Ubide T., Vasconcelos P.M., Knesel K.M., Mallmann G. (2018) Temporal constraints on magma generation and differentiation in a continental volcano: Buckland, eastern Australia. Lithos 302-303, 341-358.

[24]   Berry A.J., Stewart G.A., O’Neill H.St.C., Mallmann G., Mosselmans J.F.W. (2018) A re-assessment of the oxidation state of iron in MORB glasses. Earth and Planetary Science Letters 483, 114-123.

[23]   Leitzke F.P., Fonseca R.O.C., Sprung P., Mallmann G., Lagos M., Michely L.T., Münker C. (2017) Redox dependent behaviour of molybdenum during magmatic processes in the terrestrial and lunar mantle: Implications for the Mo/W of the bulk silicate Moon. Earth and Planetary Science Letters 474, 503-515.

[22]   McKibbin S.J., Ireland T.R., Holden P., O’Neill H.St.C., Mallmann G. (2016) Rapid cooling of planetesimal core-mantle reaction zones from Mn-Cr isotopes in pallasites. Geochemical Perspectives Letters 2, 68-77.

[21]   Fonseca R.O.C., Mallmann G., Sprung P., Sommer J.E., Heuser A., Speelmanns I., Blanchard H. (2014) Redox-controls on tungsten and uranium crystal/silicate melt partitioning and implications for the U/W and Th/W ratio of the lunar mantle. Earth and Planetary Science Letters 404, 1-13.

[20]   Mallmann G., Fonseca R.O.C., Silva A.B. (2014) An experimental study of the partitioning of trace elements between rutile and silicate melt as a function of oxygen fugacity. Anais da Academia Brasileira de Ciências (Annals of the Brazilian Academy of Sciences) 86(4), 1609-1629.

[19]   Ávila J.N., Ireland T.R., Gyngard, F., Zinner E., Mallmann G., Lugaro M., Holden P., Amari S. (2013). Ba isotopic compositions in stardust SiC grains from the Murchison meteorite: Insights into the stellar origins of large SiC grains. Geochimica et Cosmochimica Acta 120, 628-647.

[18]   McKibbin S.J., O’Neill H.St.C., Mallmann G., Halfpenny A. (2013). LA-ICP-MS mapping of olivine from the Brahin and Brenham meteorites: Complex elemental distributions in the pallasite olivine precursor. Geochimica et Cosmochimica Acta 119, 1-17.

[17]   Mallmann G., O’Neill H.St.C. (2013). Calibration of an empirical thermometer and oxybarometer based on the partitioning of Sc, Y and V between olivine and silicate melt. Journal of Petrology 54, 933-949.

[16]   Fonseca R.O.C., Laurenz V., Mallmann G., Luguet A., Hoehne N., Jochum K.P. (2012). New constraints on the genesis and long-term stability of Os-rich alloys in the Earth’s mantle. Geochimica et Cosmochimica Acta 87, 227-242.

[15]   Chemale Jr F., Mallmann G., Bitencourt M.F., Kawashita K. (2012). Time constraints on magmatism along the Major Gercino Shear Zone, southern Brazil: Implications for West Gondwana reconstruction. Gondwana Research 22, 184-199.

[14]   Fonseca R.O.C., Mallmann G., O’Neill H.St.C., Campbell I.H., Laurenz V. (2011). Solubility of Os and Ir in sulfide melt: Implications for Re/Os fractionation during mantle melting. Earth and Planetary Science Letters 311, 339-350.

[13]   Mallmann G., O’Neill H.St.C. (2009). The crystal/melt partitioning of V during mantle melting as a function of oxygen fugacity compared with some other elements (Al, P, Ca, Sc, Ti, Cr, Fe, Ga, Y, Zr and Nb). Journal of Petrology 50, 1765-1794.

[12]   Mallmann G., O’Neill H.St.C., Klemme S. (2009). Heterogeneous distribution of phosphorus in olivine from otherwise well-equilibrated spinel peridotite xenoliths and its implications for the mantle geochemistry of lithium. Contributions to Mineralogy and Petrology 158, 485-504.

[11]   Mallmann G., O’Neill H.St.C. (2007). The effect of oxygen fugacity on the partitioning of rhenium between crystals and silicate melt during mantle melting. Geochimica et Cosmochimica Acta 71, 2837-2857.

[10]   Fonseca R.O.C., Mallmann G., O’Neill H.St.C., Campbell I.H. (2007). How chalcophile is rhenium? An experimental study of the solubility of Re in sulphide mattes. Earth and Planetary Science Letters 260, 537-548.

[09]   Mallmann G., Chemale Jr. F., Ávila J.N., Kawashita K., Armstrong R.A. (2007). Isotope geochemistry and geochronology of the Nico Pérez Terrane, Rio de la Plata Craton, Uruguay. Gondwana Research 12, 489-508.

[08]   Ávila J.N., Chemale Jr. F., Mallmann G., Kawashita K., Armstrong R.A. (2006). Combined stratigraphic and isotopic studies of Triassic strata, Cuyo Basin, Argentine Precordillera. Geological Society of America Bulletin 118, 1088-1098.

[07]   Ávila J.N., Chemale Jr. F., Mallmann G., Borba, A.W., Luft, F.F. (2005). Thermal evolution of inverted basins: Constraints from apatite fission track thermochronology in the Cuyo Basin, Argentine Precordillera. Radiation Measurements 39, 603-611.

[06]   Conceição R.V., Mallmann G., Koester E., Schilling M., Bertotto G.W., Rodriguez-Vargas A. (2005). Andean subduction-related mantle xenoliths: Isotopic evidence of Sr-Nd decoupling during metasomatism. Lithos 82, 273-287.

[05]   Schilling M., Conceição R.V., Mallmann G., Koester E., Kawashita K., Hervé F., Morata D., Motoki A. (2005). Spinel-facies mantle xenoliths from Cerro Redondo, Argentine Patagonia: Petrographic, geochemical, and isotopic evidence of interaction between xenoliths and host basalt. Lithos 82, 485-502.

[04]   Rodriguez-Vargas A., Koester E., Mallmann G., Conceição R.V., Kawashita K., Weber M.B.I. (2005). Mantle diversity beneath the Colombian Andes, Northern Volcanic Zone: Constraints from Sr and Nd isotopes. Lithos 82, 471-484.

[03]   Mallmann G., Chemale Jr. F., Morales L.F.G. (2004). Evolução estrutural da porção sul do Terreno Nico Pérez, Uruguai: Registro da convergência entre as placas Rio de la Plata e Kalahari no final do Neoproterozóico. Revista Brasileira de Geociências 34, 201-212.

[02]   Philipp R.P., Mallmann G., Bitencourt M.F., Souza E.R., Souza M.M.A., Liz J.D., Wild F., Arendt S., Oliveira A.S., Duarte L., Rivera C.B., Prado M. (2004). Caracterização litológica e evolução metamórfica da porção leste do Complexo Metamórfico Brusque, Santa Catarina. Revista Brasileira de Geociências 34, 21-34.

[01]   Mallmann G., Cupertino J.A., Chemale Jr. F. (2002). Caracterização por microssonda eletrônica dos teores de cloro de apatitas e sua importância nos estudos de Traços de Fissão. Pesquisas em Geociências 29, 31-36.


No current commitment


2017 – 2017    Magmatism and Metamorphism, EMSC3024 (3rd year undergraduate), ANU 
2017 – 2018    Rocks and Minerals, EMSC2017 (2ndyear undergraduate), ANU
2014 – 2015    Mineralogy (2ndyear undergraduate), Univ. of Queensland
2014 – 2015    Igneous & Metamorphic Petrology (2ndyear undergraduate), Univ. of Queensland
2014 – 2015    Earth Materials and Processes for Engineers (1styear undergraduate), Univ. of Queensland