Marine Geology and Geochemistry
The continual discovery of diverse hydrothermal vents on the seafloor and the recognition of a potentially immense microbial biosphere associated with the global oceanic ridge system has fundamentally changed our views on how planets and life have evolved.
Childpage navigation
The Marine Geology and Geochemistry group is involved in international, interdisciplinary studies of ancient and modern ridge systems to better understand seafloor hydrothermal systems, the conditions under which they form, and the life that they support. The group is led by Gretchen Bernasconi-Green, internationally known as Gretchen Früh-Green.
Contact
Gretchen Bernasconi-Green
Our research focuses on:
- the interaction between fluids and the oceanic lithosphere;
- the geological, geochemical and biological consequences of serpentinization processes in submarine environments;
- and the cycling of elements and mass transfer between geochemical reservoirs in ophiolites and in modern ocean basins.
Participation in sea-going field programs include submersible mapping and sampling, dredging and side scan bathymetry, and deep drilling through the Integrated Ocean Discovery Program (IODP). Shore-based studies involve petrological, geochemical, radiogenic (Sr, Nd) and light stable isotope (H, C, O, S, B) and organic geochemical analyses of rocks, sediments and fluids. Our field and laboratory geochemical studies are aimed at understanding the links between geological, geochemical and microbiological processes in submarine hydrothermal systems, the chemical and isotopic composition of hydrothermal fluids and the flux of volatiles from the mantle to the hydrosphere, and the geological and geochemical consequences of serpentinization processes in submarine environments.
Current Research
Atlantis Massif Seafloor Processes: Serpentization and Life - IODP 357 Expedition
This expedition addresses two exciting discoveries in mid-ocean ridge research: off-axis, serpentinite-hosted hydrothermal activity, exemplified by the Lost City Hydrothermal Field (LCHF) on the Atlantis Massif oceanic core complex, and the significance of tectono-magmatic processes in forming and exposing heterogeneous mafic and variably serpentinized ultramafic lithosphere that are key components of slow and ultraslow spreading ridges. The expedition objectives are 1) to explore the extent and activity of the subsurface biosphere in young ultramafic and mafic seafloor, 2) assess how abiotic and biotic processes change with aging of the lithosphere and with variations in rock type, 3) quantify the role of serpentinization in driving hydrothermal systems, in sustaining microbiological communities, and in the sequestration of carbon in ultramafic rocks, and 4) characterize tectono-magmatic processes that lead to lithospheric heterogeneities and the evolution of hydrothermal activity associated with detachment faulting.
Lectures
Autumn Semester 2015
Doctoral projects
Lotta Ternieten: Carbonation and carbon geochemistry of mantle peridotites
Monica Vogel (2016): Fluid-Rock interaction and fluid fluxes in mafic and ultramafic seafloor. Diss. ETH No. 22993.
Tamara Baumberger (2011): Volatiles in Marine Hydrothermal Systems. Diss. ETH No. 20061.
Esther Schwarzenbach (2011): Serpentinization, Fluids and Life: Comparing Carbon and Sulfur Cycles in Modern and Ancient Environments. Diss. ETH No. 19588.
Thomas Schmid (2011): Clumped Isotopes – A New Tool for Old Questions. Case Studies on Biogenic and Inorganic Carbonates. Diss. ETH No. 19607.
Adélie Delacour (2007): Linking Serpentinization, Fluid Fluxes, Mass Transfer and Microbial Activity at Lost City: Geochemical and Isotopic Constraints. Diss. ETH No. 17198.
Chiara Boschi (2006): Building Lost City: Serpentinisation, Mass Transfer and Fluid Flow in an Oceanic Core Complex. Diss. ETH Thesis No. 16720.
Stable Isotope Laboratory
Our studies rely heavily on collaboration with the Stable Isotope Laboratory (Geological Institute, ETH Zurich) led by Prof. Stefano Bernasconi. Researchers in the Stable Isotope Laboratory use oxygen, carbon, hydrogen, nitrogen and sulfur isotopes in carbonates, organic matter, silicate rocks, and water as tracers in environmental, geological, and biological research. In particular, we use stable isotopes as tracers to study the origins, fluxes, and fate of natural compounds in the environment; interactions between biological and geological processes; and for reconstructions of paleoclimate, productivity, and paleoenvironmental change. We also study stable isotope signatures in carbonate, organic matter, and clay minerals as stratigraphic tools, tracers of change in marine carbon partitioning, and as monitors of diagenetic and metamorphic processes.
Projects
Hydration and carbonation of mantle peridotite: Drilling the Atlantis Massif (MAR 30°N) and the Samail ophiolite (Oman)
SNF Project No. 200021-163187 (2016-2018)
Principle investigators: G.L. Früh-Green, S.M. Bernasconi
Doctoral student: Lotta Ternieten.
Deep Carbon Observator
G.L. Früh-Green as collaborating scientist and co-Pi in the Deep Energy Project “Deep Carbon in Earth: Origins and Distribution of Abiotic Hydrocarbons”
Principle investigators: D. Cole, I. Daniel
ESSAC Delegate for Switzerland
ESSAC is the Science Committee of ECORD, the European Consortium for Ocean Research Drilling.
Previous funded projects
Fluid-Rock interaction and Fluid Fluxes in Mafic and Ultramafic Seafloor: Peridotite-hosted Hydrothermal Systems Past and Present.
SNF Project Nos. 200021-134947 (2011-2013) and 200021-146886 (2013-2015)
Principle investigators: G.L. Früh-Green, S.M. Bernasconi
Doctoral student: Monica Vogel
Unraveling Abiotic and Biotic Sources and Sinks of Carbon in Marine Hydrothermal Systems
SNF No. 200021-14389 (2012-2014)
Principle investigators: G.L. Früh-Green, S.M. Bernasconi
Postdoc: Susan Lang
Life in Extreme Environments: Carbon, Nitrogen and Sulfur Organic Geochemistry of High Alkaline Systems
SNF Project Nos. 200020-121840 (2008-2010) and 200021-131922 (2010-2012)
Principle investigators: G.L. Früh-Green, S.M. Bernasconi
Postdoc: Susan Lang
H2DEEP: Ultra-slow Spreading and Hydrogen-based Deep Biosphere
SNF Project Nos. 200020-115916 (2007-2010) and 200021-132804 (2010-2011)
Principle investigators: G.L. Früh-Green
Postdoc: Andrea Jaeschke
Doctoral student: Tamara Baumberger
ESF Collaborative Research Project 06-EuroMARC-FP-011). CRP Leader: R. Pedersen. Individual Project 4: Linking Hydrothermal Alteration, Serpentinization and Fluid Fluxes to Biological Niches at the Knipovich Ridge.
Serpentinization, Fluids and Life: Comparing Carbon and Sulfur Cycles in Modern and Ancient Environments
SNF Project Nos. 200020-116226 (2007-2009) and 200021-124669 (2009-2011)
Principle investigators: G.L. Früh-Green, S.M. Bernasconi
Doctoral student: Esther Schwarzenbach
Understanding a Peridotite-hosted Hydrothermal System on the Seafloor: Insights from Lost City
SNF Project Nos. 200020-68055 (2003-2005) and 200021-107620 (2005-2007)
Principle investigators: G.L. Früh-Green, S.M. Bernasconi
Doctoral student: Adélie Delacour
Volatiles in Submarine Environments: Implications for Carbon Cycles and the Subsurface Biosphere
ETH Project No. 0-20890-01 (2001-2005)
Principle investigator: G.L. Früh-Green
Doctoral student: Chiara Boschi