Subduction; Diffusion; Olivine; Metamorphism; Deep water cycle; Water measurements
Kempf Elias D., Hermann Jörg, Reusser Eric, Baumgartner Lukas P., Lanari Pierre (2020), The role of the antigorite + brucite to olivine reaction in subducted serpentinites (Zermatt, Switzerland), in Swiss Journal of Geosciences
, 113(1), 16-16.
Brovarone Alberto Vitale, Butch Christopher J., Ciappa Alessandra, Cleaves Henderson J., Elmaleh Agnès, Faccenda Manuele, Feineman Maureen, Hermann Jörg, Nestola Fabrizio, Cordone Angelina, Giovannelli Donato (2020), Let there be water: How hydration/dehydration reactions accompany key Earth and life processes#, in American Mineralogist
, 105(8), 1152-1160.
Malvoisin Benjamin, Austrheim Håkon, Hetényi György, Reynes Julien, Hermann Jörg, Baumgartner Lukas P., Podladchikov Yury Y. (2020), Sustainable densification of the deep crust, in Geology
, 48(7), 673-677.
Reynes Julien, Lanari Pierre, Hermann Jörg (2020), A mapping approach for the investigation of Ti–OH relationships in metamorphic garnet, in Contributions to Mineralogy and Petrology
, 175(5), 46.
Vho Alice, Lanari Pierre, Rubatto Daniela, Hermann Jörg (2020), Tracing fluid transfers in subduction zones: an integrated thermodynamic and <i>δ</i><sup>18</sup>O fractionation modelling approach, in Solid Earth
, 11(2), 307-328.
Piccoli F., Hermann J., Pettke T., Connolly J. A. D., Kempf E. D., Vieira Duarte J. F. (2019), Subducting serpentinites release reduced, not oxidized, aqueous fluids, in Scientific Reports
, 9(1), 19573-19573.
Jollands Michael C., Kempf Elias, Hermann Jörg, Müntener Othmar (2019), Coupled inter-site reaction and diffusion: Rapid dehydrogenation of silicon vacancies in natural olivine, in Geochimica et Cosmochimica Acta
, 262, 220-242.
Tollan Peter, Ellis Ben, Troch Juliana, Neukampf Julia (2019), Assessing magmatic volatile equilibria through FTIR spectroscopy of unexposed melt inclusions and their host quartz: a new technique and application to the Mesa Falls Tuff, Yellowstone, in Contributions to Mineralogy and Petrology
, 174(3), 24-24.
TollanPeter, HermannJörg (2019), Arc magmas oxidized by water dissociation and hydrogen incorporation in orthopyroxene, in Nature Geoscience
, 12, 667-671.
Tollan Peter M. E., O’Neill Hugh St. C., Hermann Jörg (2018), The role of trace elements in controlling H incorporation in San Carlos olivine, in Contributions to Mineralogy and Petrology
, 173(11), 89-89.
Reynes Julien, Jollands Michael, Hermann Jörg, Ireland Trevor (2018), Experimental constraints on hydrogen diffusion in garnet, in Contributions To Mineralogy and Petrology
, 173(9), 1-20.
Kempf Elias D., Hermann Jorg (2018), Hydrogen incorporation and retention in metamorphic olivine during subduction: Implications for the deep water cycle, in Geology
, 46(6), 571-574.
Padrón-Navarta J. A., Hermann J. (2017), A Subsolidus Olivine Water Solubility Equation for the Earth's Upper MantleWater Solubility Equation for Olivine, in Journal of Geophysical Research: Solid Earth
, 122(12), 9862-9880.
Tollan Peter M. E., Smith Rachel, O’Neill Hugh St.C., Hermann Jörg (2017), The responses of the four main substitution mechanisms of H in olivine to H2O activity at 1050 °C and 3 GPa, in Progress in Earth and Planetary Science
, 4(1), 14-14.
Water has a profound influence on how Earth operates. The addition of small amounts of water can decrease the melting point of rocks by several hundred degrees. Water in magmas has a dramatic influence on the way magmas flow, and water-rich lavas have the potential for catastrophic eruptions whereas volcanos with water-poor lavas represent a lesser natural hazard. Water also influences many physical properties of rocks. Tiny amounts of water affect the electric conductivity and weaken mantle minerals. As a consequence, it has been suggested that plate tectonics as it operates on Earth is only possible if small amounts of water are present in the Earth’s interior. In spite of the fundamental importance of water carried deep into the Earth in controlling the evolution of our planet, there are still many open questions.This project aims to investigate some key processes in the Earth’s deep water cycle. The release of water from the Earth’s interior occurs through magmatism at mid ocean ridges and volcanic arcs. This continuous loss of water must be compensated by water transported along subduction zones back into the mantle. However, it is not clear if the deep water cycle is at steady state and the amount of water transported to the deep mantle is poorly constrained. This study investigates how water is transferred in subduction zones from hydrous minerals, which are generally stable only to about 100 km depth, to nominally anhydrous minerals that are able to carry water to the deeper mantle. We will use a wide variety of mafic and ultramafic rocks from well-characterised areas in the Alps as a natural laboratory to study this process. We aim to investigate how and how much water is incorporated during progressive dehydration reactions into olivine, garnet, pyroxene and rutile as a function of pressure, temperature and composition. These results will be compared to water incorporation in lithospheric mantle sections that were undersaturated in water. Special emphasis will be placed on investigating whether the nominally anhydrous minerals lost or gained water by diffusion during their journey back to the surface by comparing natural samples with experimental results. If water diffusion is observed, we will evaluate the potential of such diffusion profiles to obtain information on the duration of metamorphic processes at moderate temperatures. To achieve the goals of this project, protocols for water measurements in geological materials must be established for the new infrared spectroscopy laboratory in Bern and the SwissSIMS in Lausanne. These developments will serve a wider Earth Science community in Switzerland and abroad in the fields of igneous and metamorphic petrology, volcanology, ore deposits and structural geology. Funding is requested for a Post Doctoral researcher who will focus on the development of water measurement protocols, and two PhD students working on water transfer in ultramafic and mafic systems, respectively.