Project

Back to overview

High Pressure natural fluids in the Earths upper mantle and lower crust

English title High Pressure natural fluids in the Earths upper mantle and lower crust
Applicant Thompson Alan
Number 117604
Funding scheme Project funding (Div. I-III)
Research institution Institut für Geochemie und Petrologie ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Geochemistry
Start/End 01.01.2008 - 30.09.2012
Approved amount 504'387.00
Show all

All Disciplines (3)

Discipline
Geochemistry
Mineralogy
Other disciplines of Earth Sciences

Keywords (10)

experimental petrology; lherzolite; peridotite; upper mantle; Metasomatic fluids; mineral solubility; water; fluid flow; rock melting; high pressure

Lay Summary (English)

Lead
Lay summary
Metasomatic fluids are involved in many natural processes within the Earths crust and mantle.
High pressure -temperature (PT) fluids usually are H2O-rich but contain increased amounts of dissolved minerals. Furthermore, water considerably lowers the melting point of silicate rocks because H2O is very soluble in high pressure rock melts (magma). At high P-T, aqueous fluids and hydrous silicate melts approach each other in their chemical and physical characteristics.
This study will determine the fluid and melt composition characteristics close to the melting reactions in crystalline continental crust (related to granite), and in subducted ocean crust (eclogite) and mantle (simplified peridotite). In addition, the degree of solubility of rocks and minerals in H2O will be examined in terms of solubility mechanisms related to silica polymerisation, species hydration and bulk physical fluid properties (density).
Our long term aim is to understand and eventually predict how natural fluids moving along likely gradients of PT in the different chemical compositional regimes of the crystalline Earths crust, will change their physical and chemical properties. These changes result in reactions that usually locally decrease rock volume and expel fluid, and elsewhere cause massive precipitation of minerals producing mineral deposits but which also choke up the fluid flow.
These quantifications will later be applied to the subduction zone multiflow systems related to earthquakes and arc volcanism, and the deep metasomatism beneath continents associated with deep mantle intrusions and diamond-bearing kimberlite events.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Density and viscosity of hydrous magmas and related fluids and their role in subduction zone processes
Hack Alistair C. (2011), Density and viscosity of hydrous magmas and related fluids and their role in subduction zone processes, in Journal of Petrology, 52(7&8), 1333-13362.
Experimental investigation of the solubility of albite and jadeite in H2O at 500 and 600°C, and 1 - 2.25 GPa
Wohlers Anke Manning Craig E. & Thompson Alan B. (2011), Experimental investigation of the solubility of albite and jadeite in H2O at 500 and 600°C, and 1 - 2.25 GPa, in Geochimica et Cosmochimia Acta, 75, 2924-2935.

Collaboration

Group / person Country
Types of collaboration
Universität Bern Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
UCLA (University of California Los Angeles) United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Associated projects

Number Title Start Funding scheme
143695 Phase relations, compositions and trace element partitioning of solid and mobile phases in the hydrous MORB system at 2 - 3.5 GPa 01.10.2012 Project funding (Div. I-III)
105356 Major and trace element composition and partitioning behaviour of hydrous fluids and melts in lithospheric rocks 01.10.2004 Project funding (Div. I-III)

-