Project

Back to overview

Magmas, ore deposits and geodynamic evolution at convergent margins

English title Magmas, ore deposits and geodynamic evolution at convergent margins
Applicant Chiaradia Massimo
Number 149147
Funding scheme Project funding
Research institution Département des sciences de la Terre Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Geochemistry
Start/End 01.02.2014 - 31.01.2016
Approved amount 150'000.00
Show all

Keywords (10)

radiogenic isotopes; amphibole partition coefficient for Cu; volcanic gases; arc magmatism; experimental petrology; high Sr/Y; geochronology; subduction; porphyry copper; arc magmas

Lay Summary (French)

Lead
Trois quarts du Cu mondial sont fournis par les gisements de type porphyre, associés avec les roches magmatiques d’arc. Tandis que les processus magmatiques et hydrothermaux à basse profondeur dans la croûte qui amènent à la précipitation des métaux dérivants du magma sont bien connu, les processus géodynamiques et magmatiques se passant à grande profondeur dans le manteau et la croûte terrestre, qui jouent un rôle essentiel dans la formation de ces gisements, sont peu connus.
Lay summary

Lead

Trois quarts du Cu mondial est fourni par les gisements de type porphyre (incluant, le porphyre de Cu, les skarns, et la suite des gisements épithermaux). Ces gisements sont associés avec les roches magmatiques d’arc, produites par la subduction de la croûte océanique dessous la croûte continentale ou océanique. Tandis que les processus magmatiques et hydrothermaux à basse profondeur dans la croûte qui amènent à la précipitation des métaux dérivants du magma sont relativement bien connu, les processus géodynamiques et magmatiques se passant à grande profondeur dans le manteau et la croûte terrestre et qui jouent un rôle essentiel dans la formation de ces gisements sont peu connus.

 

Contenu et objectifs du travail de recherché

Le but de ce projet est de mieux comprendre quelle est l’influence des processus profonds dans la formation des gisements de type porphyre. En particulier nous voulons mieux comprendre le lien entre la géodynamique des zones de subduction, la génération des magmas avec une géochimie particulière et la formation des gisements de type porphyre en étudiant des complexes magmatiques minéralisés et non-minéralisés et en les comparant entre eux.

 

Contexte scientifique et social du projet de recherche

Notre travail générera des résultats qui nous aiderons à mieux comprendre la genèse des gisements de type porphyre et donc à raffiner les modèle génétiques qui sont à la base des campagnes d’exploration des compagnies minière pour la recherche des nouvelles ressources. Ils nous aiderons aussi à mieux comprendre l’évolution de la croûte et les échanges des métaux entre croute et manteau de la Terre.

Direct link to Lay Summary Last update: 15.10.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Crustal thickness control on Sr/Y signatures of recent arc magmas: an Earth scale perspective.
Chiaradia Massimo (2015), Crustal thickness control on Sr/Y signatures of recent arc magmas: an Earth scale perspective., in Scientific reports, 5, 8115-8115.
High Sr/Y magmas and porphyry-type deposits: what is the role of timescales of magmatic processes?
Bellver-Baca M. T. Chiaradia M. (2015), High Sr/Y magmas and porphyry-type deposits: what is the role of timescales of magmatic processes?, in Mineral resources in a Sustainable World. 13th SGA Biennial Meeting 2015, Nancy, France.
The Yanaurcu volcano (Western Cordillera, Ecuador): A field, petrographic, geochemical, isotopic and geochronological study
Beguelin Paul, Chiaradia Massimo, Beate Bernardo, Spikings Richard (2015), The Yanaurcu volcano (Western Cordillera, Ecuador): A field, petrographic, geochemical, isotopic and geochronological study, in LITHOS, 218, 37-53.
Time sacles of Mineral Systems - Advances in Understanding Over the Past Decade
Chiaradia M. Schaltegger U. Spikings R. (2014), Time sacles of Mineral Systems - Advances in Understanding Over the Past Decade, in Kelley K. D. Golden H. C. (ed.), Society of Economic Geologists, Boulder, CO, 37-58.

Collaboration

Group / person Country
Types of collaboration
Prof. Peter Ulmer, ETH, Zürich, Switzerland Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Prof. François Bussy, University of Lausanne, Switzerland Switzerland (Europe)
- Research Infrastructure
Dr. Richard Spikings, University of Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Prof. Alessandro Aiuppa, University of Palermo, Italy Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Dr. Serge Stoll, University of Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Prof. Othmar Müntener, University of Lausanne, Switzerland Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Bernardo Beate, Escuela Politecnica Nacional, Quito, Ecuador Ecuador (South America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Swiss Geoscience Meeting Talk given at a conference RAFC processes and temporal factors favouring porphyry mineralization in high Sr/Y magmas 20.11.2015 Basel, Switzerland Bellver Baca María Teresa;
SEG 2014: Building Exploration Capability for the 21st Century Talk given at a conference Time Scales of Mineral Systems—Advances in Understanding Over the Past Decade 27.09.2015 Keystone, CO, USA, United States of America Chiaradia Massimo;
13th SGA Biennial Meeting Talk given at a conference High Sr/Y magmas and porphyry-type deposits: what is the role of timescales of magmatic processes? 24.08.2015 Nancy, France Bellver Baca María Teresa;
Journée Metallogénique Talk given at a conference High Sr/Y magmas and porphyry-type systems. The role of different timescales of magmatic processes 13.03.2015 ETH Zürich, Switzerland Bellver Baca María Teresa; Chiaradia Massimo;
Swiss Geoscience Meeting Poster Magmatic and time-scale factors which control the link between porphyry-type systems and high Sr/Y magmas 21.11.2014 Fribourg, Switzerland Bellver Baca María Teresa;


Awards

Title Year
Best student oral presentation conferred to Maria Teresa Bellver Baca at the 13th biennial SGA meeting, August 24-27, Nancy, France. Award based on the scientific merit and presentation quality. Presentation title: “High Sr/Y magmas and porphyry-type deposits: what is the role of timescales of magmatic processes?” 2015

Associated projects

Number Title Start Funding scheme
162415 Magmas, ore deposits and geodynamic evolution at convergent margins 01.02.2016 Project funding
137663 Magmas, ore deposits and geodynamic evolution at a convergent margin: the case of Ecuador 01.01.2012 Project funding
137663 Magmas, ore deposits and geodynamic evolution at a convergent margin: the case of Ecuador 01.01.2012 Project funding

Abstract

The present proposal is for a 2-year extension of the SNF project N. 200020_137663 “Magmas, ore deposits and geodynamic evolution at a convergent margin: the case of Ecuador”. Funds are asked for a 2-year PhD student salary, fieldwork and attendance to conferences by the PhD student and the applicant, as well as for analytical work. The PhD student will be engaged for this project from 1 January 2014.In the past years (SNF Projects N. 200021-109636, 200020-117616, 200020-126896, 200020_137663) we have investigated the time relationship between adakite-like rocks and mineralization (in Miocene porphyry-systems of Ecuador, in the giant porphyry-related Miocene system of Yanacocha and in the Oligocene skarn-porphyry mineralization of Coroccohuayco) and the petrogenetic significance of adakite-like rocks. We have also investigated the petrogenetic significance of the transition from normal calc-alkaline to adakite-like signatures that occurs during the Quaternary in several volcanic edifices of northern Ecuador. The main results of our previous investigations can be summarized as follows: (i) adakite-like rocks are formed by magmatic evolution at variably deep crustal levels and under hydrous conditions, favoring the stability of amphibole ± garnet but not that of plagioclase; (ii) porphyry-type deposits form in association with adakite-like rocks during a few Ma (~<1-3 Ma) towards the end of a several Ma long (=6 Ma) transition from normal to adakite-like magmatism.The results obtained in the previous years invite us to focus now on two specific questions (whose answers represent our objectives) about the association between adakite-like (high Sr/Y) magmas and porphyry systems: 1. Why porphyry systems occur in the final stages of a magmatic cycle characterized by a systematic increase in Sr/Y values through time? 2. Why magmatic cycles with increasing Sr/Y values associated with porphyry systems last several Ma as opposed to similar cycles in “barren” systems which last only 0.0X to 0.X Ma? A third point that we would like to address in synergy with the above ones is a more general: 3. Understanding of the magmatic behavior of Cu in active arc-related magmatic systems.Points 1 and 2 above will represent the focus of investigation of a PhD student (Subproject A: Magmatic and time-scale factors controlling the association of porphyry-type deposits with high Sr/Y magmas). They will be carried out in the giant porphyry-associated Au-Cu district of Yanacocha (northern Peru) and in the volcanic complex of Chachimbiro (northern Ecuador). Point 3 will be the research focus of the applicant in collaboration with Master students (Subproject B: Magmatic behavior of copper in arc-related systems) and will be carried out in the Aeolian islands of Vulcano, Stromboli and Lipari. At all sites we will monitor changes of some critical parameters such as metal (in particular Cu) and volatile (H2O, CO2, S, Cl, F) contents, oxidation state, depth of the reservoir during the temporal evolution of magmatic rocks of mineralized and non-mineralized systems from low to high Sr/Y values in order to better understand the role of high Sr/Y magmas in the formation of porphyry-type deposits. Investigation of the behavior of volatiles and metals like copper in “normal” barren systems (i.e., Aeolian islands) both in magmatic rocks and in volcanic gases will help us to better understand the factors which may lead to preferential association of porphyry-type deposits with high Sr/Y magmas.
-