Project

Back to overview

Magmatic processes in the continental crust: from source variations to emplacement mechanisms

English title Magmatic processes in the continental crust: from source variations to emplacement mechanisms
Applicant Müntener Othmar
Number 156421
Funding scheme Project funding (Div. I-III)
Research institution Institut de Minéralogie et Géochimie Université de Lausanne
Institution of higher education University of Lausanne - LA
Main discipline Other disciplines of Earth Sciences
Start/End 01.10.2014 - 31.03.2020
Approved amount 564'696.00
Show all

All Disciplines (4)

Discipline
Other disciplines of Earth Sciences
Geochemistry
Mineralogy
Geology

Keywords (6)

Igneous petrology; Rheology of mafic sills; Thermal evolution; Lower crust; Source composition, Hf, O isotopes; Intraplutonic contacts

Lay Summary (German)

Lead
Magmatic processes in the continental crust are studied within this SNF funded research project. We are interested to better understand and quantify how magmas that were formed in the Earth upper mantle will change their composition and physical properties, once they intrude the crust, and how and on what length scales these magmas interact with the continental crust. We are doing this by looking at outrcrop relations in the field, chemical analyses and physical modelling. Our goal is to better understand how the continental crust of the Earth was formed and modified over geological timescales.
Lay summary

Das übergeordnete Ziel unserer Untersuchungen ist es, die Erkenntnisse über die Wege von Magma in der Kruste und wie diese Schmelzen mit ihrer Umgebung interagieren zu vertiefen.  Wir werden mit Hilfe modernster analytischer Techniken Mineralien untersuchen, ob das Wachstum derselben das Vorhandensein chemisch verschiedener Schmelzen nachweisen kann. Solche Prozesse laufen bevorzugt in den heissen Teilen der tieferen Kruste ab. Sobald die Schmelzen die Quelle in der tiefen Kruste verlassen und in flachere Niveaus der Kruste aufsteigen, werden sie abgekühlt und beginnen zu kristallisieren. Je nach Mineralgehalt und chemischer Zusammensetzung bilden sich verschiedene Texturen, aus denen wir mehr über physikalische Parameter wie Viskosität während der Kristallisation ableiten können.

Unsere Arbeit wird neue Informationen über die Kontaminierungsprozesse in der tiefen Kruste liefern, wie Magmen aufsteigen und schlussendlich entweder in der Tiefe kristallisieren oder an die Erdoberfläche gelangen. 

Direct link to Lay Summary Last update: 03.10.2014

Responsible applicant and co-applicants

Employees

Publications

Publication
Multispecies diffusion of yttrium, rare earth elements and hafnium in garnet
Bloch E M, Jollands M C, Devoir A, Bouvier A-S, Ibañez-Mejia M, Baumgartner L P (2020), Multispecies diffusion of yttrium, rare earth elements and hafnium in garnet, in Journal of Petrology, 1-61.
New Ti-in-quartz diffusivities reconcile natural Ti zoning with time scales and temperatures of upper crustal magma reservoirs
Jollands Michael C., Bloch Elias, Müntener Othmar (2020), New Ti-in-quartz diffusivities reconcile natural Ti zoning with time scales and temperatures of upper crustal magma reservoirs, in Geology, 48(7), 654-657.
Coupled inter-site reaction and diffusion: Rapid dehydrogenation of silicon vacancies in natural olivine
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.
Testing Orthopyroxene Diffusion Chronometry on Rocks From the Lanzo Massif (Italian Alps)
Jollands Michael C., Müntener Othmar (2019), Testing Orthopyroxene Diffusion Chronometry on Rocks From the Lanzo Massif (Italian Alps), in Journal of Geophysical Research: Solid Earth, 124(8), 7822-7841.
Mineral growth in melt conduits as a mechanism for igneous layering in shallow arc plutons: mineral chemistry of Fisher Lake orbicules and comb layers (Sierra Nevada, USA)
McCarthy Anders, Müntener Othmar (2017), Mineral growth in melt conduits as a mechanism for igneous layering in shallow arc plutons: mineral chemistry of Fisher Lake orbicules and comb layers (Sierra Nevada, USA), in Contributions to Mineralogy and Petrology, 172, 55.
Melt Extraction Zones in Shallow Arc Plutons: Insights from Fisher Lake Orbicules (Sierra Nevada, Western USA)
McCarthy Anders, Müntener Othmar, Bouvier Anne-Sophie, Baumgartner Lukas (2016), Melt Extraction Zones in Shallow Arc Plutons: Insights from Fisher Lake Orbicules (Sierra Nevada, Western USA), in Journal of Petrology, 57(10), 2011-2052.
Comb layering monitors decompressing and fractionating hydrous mafic magmas in subvolcanic plumbing systems (Fisher Lake, Sierra Nevada, USA)
McCarthy Anders, Müntener Othmar (2016), Comb layering monitors decompressing and fractionating hydrous mafic magmas in subvolcanic plumbing systems (Fisher Lake, Sierra Nevada, USA), in Journal of Geophysical Research, 121, 8595-8621.

Collaboration

Group / person Country
Types of collaboration
Prof. Urs Schaltegger, Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Dr. Tom Sisson United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Dr Thomas Müller, Bochum Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Luca Caricchi Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
AGU Meeting 2019 Poster Tracking Magma Transfer and Country-rock Interactions through Garnet Microchemistry. 06.12.2019 San Francisco, United States of America Müntener Othmar; Devoir Arnaud;
Mineralogical Society of America Cenntenial Meeting Individual talk Lower crust formation and differentiation constrained by field studies and experimental petrology 20.06.2019 Washington DC, United States of America Müntener Othmar;
EGU Vienna 2019 Poster Magmatic residence times and T-t history from REE Y- Cr- P zonation in garnet xenocrysts in mid-crustal granite 06.04.2019 Vienna, Austria Müntener Othmar; Devoir Arnaud;
AGU Fall Meeting 2018 Individual talk Fast diffusive loss of H from Si vacancies in olivine 06.12.2018 Washington DC, United States of America Jollands Michael; Müntener Othmar;
GSA Annual Meeting 2018 Individual talk Granite formation controlled by phase equilibria in the crustal column: Experimental perspectives from equilibrium and fractional crystallization 04.11.2018 Indianapolis, United States of America Müntener Othmar;
AGU Meeting 2016 Poster Relative diffusivities of Cr, Al, Ti and Ca in natural orthopyroxene from the Lanzo massif (Italy) and their potential use in determining uplift rates. 12.12.2016 San Francisco, United States of America Jollands Michael; Müntener Othmar;
AGU 2015 Poster Melt extraction zones in shallow arc plutons: insights from Fisher Lake orbicules and comb layers, Northern Sierra Nevada 07.12.2015 San Francisco, United States of America Müntener Othmar; McCarthy Anders;


Awards

Title Year
Niggli Medal for promising young researchers in Switzerland 2020

Associated projects

Number Title Start Funding scheme
135511 Crustal growth processes: an integrated field and geochemical approach 01.06.2011 Project funding (Div. I-III)
163991 A FEG-Electronprobe Microanalyzer for analysis of Earth materials at the sub-micron scale 01.04.2016 R'EQUIP
177026 Re-equiping the noble gas laboratory to perform state of the art science, University of Geneva 01.03.2018 R'EQUIP

Abstract

This proposal requests funding to perform field and analytical studies on shallow and deep plutonic rocks to understand time scales of crystallization, melt extraction and reservoir evolution. The grant will support Othmar Müntener, and the field and analytical expenses of PhD, a postdoctoral researcher, and to complete an ongoing PhD thesis .I propose a combined field, detailed analytical and modelling study on the mechanisms of shallow plutonic melt segregation in amalgamated plutons and the evolution of magma sources to get constraints on segregation and rejuvenation of magma bodies and how these processes interact in space and time. Constraints on magma temperatures in shallow plutonic systems derived from thermal models of contact aureoles and from magma rheology experiments, and calculations indicate that emplacement temperatures in some shallow plutonic systems might be higher than previously thought. Since temperature and H2O content are the most important parameters to constrain density, fertility, crystal cargo and viscosity during magma emplacement, and since magma emplacement has been shown to be mostly incremental for many plutonic and volcanic systems, field geometries and analytical studies on shallow plutonic rocks are crucial to the understanding of accretion mechanics of dikes and sills and their post-emplacement modifications.In order to achieve these research goals, we will conduct detailed field work on shallow plutonic systems where the basic geology and petrology is well established. The approach of the project in the Torres del Paine area is to derive detailed Hf and oxygen isotopic studies on a series of well dated igneous rocks that document arc migration over the last 30 my . In addition field geometries will be explored to constrain physical parameters (crystal content, pressure, temperature, fH2O, fO2, mineral zoning, ascent velocities), combined with detailed AMS studies and structural geology to decipher the deformation mechanisms, yield strengths, differential stress and/or strains and viscosity of partially molten sill complexes. Ionprobe measurements on selective trace elements and/ or isotopes in plagioclase and/or K-feldspar will be used to determine time-scales of mineral growth in both the mafic sills and the diapriric felsic segregations. One of the largest layered complexes of mafic magmas (Ivrea zone, N-Italy) will be investigated to understand the mechanisms of magma mixing/assimilation in the deep crust. The time integrated geochemical evolution and the available age data indicate high temperature conditions prevailing for several 10’s of millions of years. If so, the interaction of intruding magmas with the surrounding lower crustal rocks will profoundly change the primary chemical signature of the crystallizing magmas. We propose a novel study (Project C) that takes advantage of in-situ analysis of d18O in lower crustal rocks, and in particular garnet, to monitor emplacement mechanisms of mafic rocks and their interaction with metapelitic country rocks. We will use samples from well-defined natural systems (Ivrea zone, Italy, Kohistan Pakistan), to monitor various sources and physico-chemical interactions of mafic and felsic magmas. These data provide first order constraints on the hypothesis that intermediate to silicic magmas rising to construct plutons in intermediate to upper crustal levels acquire most of their chemical signature in the lower crust, while the geometries are mostly acquired during emplacement. How they rise, via diapirs, dikes or a combination of both is debatable. An ongoing PhD study (Project D) looks in detail at such melt extraction zones (schlieren and comb-layering) along intra-plutonic contacts, in several spectacularly exposed areas in the Sierra Nevada (California). Phase petrology, size frequency distribution, and crystal size distributions will be used to identify the key parameters that generate such intraplutonic contacts.
-