Project

Back to overview

Genesis of Massive Sulphide Deposits in Oman

Applicant Diamond Larryn W.
Number 146211
Funding scheme Project funding (Div. I-III)
Research institution Institut für Geologie Universität Bern
Institution of higher education University of Berne - BE
Main discipline Geochemistry
Start/End 01.10.2013 - 30.09.2016
Approved amount 323'570.00
Show all

All Disciplines (2)

Discipline
Geochemistry
Geology

Keywords (4)

hydrothermal; ore deposit; process; massive-sulfide

Lay Summary (German)

Lead
Die chemische und physikalische Prozesse, die zur Entstehung von Kupfer- und Goldführende massiv-sulfidischer Lagerstätten am Meeresboden führen, sind gut bekannt nur wo sie direkt beobachtet werden können (z.B. beim Austritt heisser, metallreicher Fluid an "schwarzen Rauchern"). Dieses Projekt erforscht die Prozesse, die tief unterhalb des Meeresbodens ablaufen, anhand Gesteinen eines fossilen ozeanischen Krustenprofiles, das an Land aufgeschlossen ist.
Lay summary

Das fossile ozeanische Krustenstück befindet sich im Bergland vom Sultanat von Oman. Die Arbeiten im Gelände konzentrieren sich vor allem auf Gesteine, die mit dem hellgrünen Mineral Epidot angereichert sind, da diese Gesteine vermutlich den tiefen Ursprung (die "Wurzel") des erzbildenden Systems darstellen. Geologische Kartierungen, Probennahmen und diverse chemische und mineralogische Analysen werden durchgeführt. Die gewonnen Daten dienen anschliessend als Eingabe für Computersimulationen, die die erzbildenden Prozesse nachbilden sollen. Wir beabsichtigen die exakten chemischen Reaktionen zu bestimmen, die die Epidotanreicherung verursachen und wir werden den Einfluss dieser Reaktionen auf die Erzbildung am Meeresboden untersuchen. Zum Beispiel könnten unsere Forschungsergebnisse erklären warum einige kupferreiche Massivsulfide goldführend sind, andere aber nicht.

Wir erwarten, dass die Ergebnisse dieser Studie den Kenntnissstand über die fundamentalen Prozesse der Meerwasser - Gesteins Interaktion in der tiefen ozeanischen Kruste erweitern werden. Unsere Erkenntnisse könnten zudem Explorationsgeologen bei der weltweiten Suche nach massiv-sulfidischen Lagerstätten unterstützen.


Direct link to Lay Summary Last update: 01.08.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Sub-seafloor epidosite alteration: Timing, depth and stratigraphic distribution in the Semail ophiolite, Oman
Gilgen Samuel A., Diamond Larryn W., Mercolli I. (2016), Sub-seafloor epidosite alteration: Timing, depth and stratigraphic distribution in the Semail ophiolite, Oman, in Lithos, 260, 191-210.
Volcanostratigraphic Controls on the Occurrence of Massive Sulfide (VMS) Deposits in the Semail Ophiolite, Oman
Gilgen Samuel A., Diamond Larryn W., Mercolli Ivan, Al-Tobi Khalid, Maidment David W., Close Robert, Al-Towaya Ahmed (2014), Volcanostratigraphic Controls on the Occurrence of Massive Sulfide (VMS) Deposits in the Semail Ophiolite, Oman, in Economic Geology, 109, 1585-1610.

Collaboration

Group / person Country
Types of collaboration
Oman Mining Co. Oman (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Directorate General of Minerals, Oman Oman (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Mawarid Mining Company Oman (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Earth Secrets Ltd. Oman (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Gentor Resources Ltd. Oman (Asia)
- 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
Gordon Research Conference: Geochemistry of Mineral Deposits Poster Sub-seafloor hydrothermal alteration in the Semail Ophiolite, Sultanate of Oman: Remote sensing opportunities and links to VMS deposit genesis 19.06.2016 Les Diablerets, Switzerland Belgrano Thomas; Diamond Larryn W.;
Swiss Journée Métallogénique Poster Porosity of epidosites in the oceanic crust 18.03.2016 University of Bern, Switzerland Diamond Larryn W.;
Goldschmidt Conference Talk given at a conference Timing mismatch between VMS deposits and footwall epidosite alteration in the Semail Ophiolite 16.08.2015 Prague, Czech Republic Gilgen Samuel; Diamond Larryn W.;
Swiss Journée Métallogénique Talk given at a conference Footwall alteration as an exploration vector to VMS deposits? (2) Timing of epidosites relative to VMS deposits in the Oman ophiolite 13.03.2015 ETH-Zürich, Switzerland Gilgen Samuel; Diamond Larryn W.;
Swiss Journée Métallogénique Talk given at a conference Footwall alteration as an exploration vector to VMS deposits? (1) Regional distribution of epidosites in the Semail ophiolite, based on satellite infrared images and field mapping 13.03.2015 ETH-Zürich, Switzerland Diamond Larryn W.; Gilgen Samuel;
Society of Economic Geologists (SEG) Conference Poster Tracking the missing link between epidosites and volcanogenic massive sulphide (VMS) deposits in the Hatta area, Semail ophiolite, Oman 24.09.2014 Keystone, Colorado, United States of America Gilgen Samuel; Diamond Larryn W.;
Society of Economic Geologists (SEG) Conference Talk given at a conference Volcanostratigraphic controls on the occurrence of massive sulphide (VMS) deposits in the Semail Ophiolite, Oman 24.09.2014 Keystone, Colorado, United States of America Diamond Larryn W.; Gilgen Samuel;
Swiss Journée Métallogénique Poster Volcanostratigraphic Controls on the Occurrence of Massive Sulfide (VMS) Deposits in the Semail Ophiolite, Oman 14.03.2014 University of Geneva, Switzerland Diamond Larryn W.; Gilgen Samuel;


Associated projects

Number Title Start Funding scheme
169653 Genesis of massive sulphide deposits in Oman 01.10.2016 Project funding (Div. I-III)

Abstract

This project addresses aspects of water-rock interaction and mass redistribution in sub-seafloor hydrothermal systems within oceanic crust. Among the features of these systems are extensive zones of rock alteration and associated volcanogenic massive sulphide (VMS) deposits, which are important resources of Cu, Zn, Au, Ag and Pb. Our project aims to fill two gaps in knowledge regarding these features: (1) Published models of hydrothermal alteration suggest there should be a strict spatial relationship between VMS deposits on the seafloor and deep, high-temperature hydrothermal reaction zones (identified by epidote-rich rocks, "epidosites"). However, this relationship remains untested and its basis is incompletely explained. (2) VMS deposits in mafic host rocks and their oxidized, weathered equivalents (gossans) display a wide range of gold contents. However, the reasons for these variations are unclear. We will investigate both issues in the Semail Ophiolite in northern Oman, owing to its ideal field relations and extensive geological literature. Our previous work in Oman has defined specific field areas and suitable research approaches for this project. We intend to map and sample epidosites, fresh VMS deposits and gossan deposits, then analyse the samples with a variety of mineralogical, chemical and isotopic methods. We will interpret the data on epidosites in terms of geological setting, fluid fluxes and physicochemical conditions of water-rock interaction. We will simulate these processes numerically using a reactive-transport code, to define the controlling reactions and flow parameters. The new data on VMS deposits and gossans will be interpreted in terms of geochemical processes that can explain the observed distributions of gold. These span the magmatic origin of the host rocks and the evolution of fluid properties that control gold mobility, whether in the hydrothermal or subaerial environments. This should provide a comprehensive model to explain the genetic differences between gold-bearing and gold-poor deposits. The results will be applicable to the exploration industry.In 2010 we started research in Oman as a pilot study, using our own funds to employ a PhD student. In this proposal we solicit support from SNF to continue the project for a further 3 years: 1.5 years of funding for the existing PhD student and 3 years for a new student. In addition to salaries for the PhD students we request funding for fieldwork costs, laboratory analytical costs and participation in conferences, for the period April 2013 to March 2015. The Applicant is the academic supervisor of the doctoral theses. The products of this research will be a series of conference presentations and publications in international, peer-reviewed, scientific journals. In addition, we will have provided scientific training for two PhD candidates and several Master students.
-