Short course - Geochemistry of Hydrothermal Ore Deposits

This intensive 8-day course will explore the fundamentals of ore-forming fluids in hydrothermal systems, including practical aspects of ore element geochemistry, ore mineral assemblages, water-rock interactions, and the tools to recognize them. The course will provide an introduction to concepts that are critical to understanding hydrothermal mineralization and exploring for a variety of deposit types in both continental and submarine environments. We will examine mineral stabilities and controls on metal solubility in hydrothermal systems, P-T- pH-redox conditions and their importance in ore formation, controls on water-rock interaction and the integration of basic field and laboratory analyses to unravel processes of ore formation. Leading experts in the field will provide participants with a practical understanding of the links between geology, mineralogy and geochemistry of a variety of hydrothermal systems ... “from drill core to the laboratory and back”.

The course will be presented as four 2-day modules that will focus on the following topics:

  • A Practical Guide to the Ore Elements, Minerals and Fluids
  • Orogenic Gold Deposits and Porphyry-Related Systems
  • Epithermal Systems and Iron Oxide-Copper-Gold Deposits
  • Volcanogenic Massive Sulfides and Ores in Surficial Environments

The course is open to graduate students from any university as well as professionals in industry. Graduate students may be eligible for credit toward their degree programs. Industry participants may receive credit toward professional training requirements.

Course Timetable

Days 1 and 2: A Practical Guide to the Ore Elements, Minerals and Fluids ( Oct 21 & 22 )
Hydrothermal fluids can transport the full spectrum of ore elements from A to Z. Their sources, transport mechanisms and precipitation fundamentally determine where and when mineral deposits will form. But how are geochemically scare elements, with very low crustal abundances, concentrated into ore deposits? Most geologists have a general understanding of the important control of temperature − Cu-rich ores commonly form at high temperature and Zn-rich ores form at lower temperature. But why does this happen? To answer these questions, geologists require knowledge of the concentrations of ore elements in the environment, how they are carried in solution, and what causes them to precipitate. Most of the common ore minerals are sulfides, and so the formation of many ore deposits is controlled by sulfide mineral stabilities and their solubilities in different solutions. But why are some ore elements (e.g., Cu, Co, Bi, In, Sn, etc.) found in one deposit type while others (e.g., Zn, Ag, Pb, Sb, Tl, etc.) are found in another? These questions will be addressed using simple geochemical models of ore-forming fluids in a range of deposit types. The first day will explore the response of different ore elements to different forms of metal complexing in hydrothermal fluids (e.g., hard versus soft acids and bases) and factors that influence their distribution among the ore types (e.g., trace element substitution in different ore minerals). The second day will introduce the basic principles of ore mineral stabilities and how to interpret the mineralogy of hydrothermal ore deposits in terms of fundamental controls on ore formation (temperature, pH, redox state). We will examine why some deposits contain only pyrite and others mostly pyrrhotite or magnetite, and learn some simple rules to understand these kinds of mineralogical differences. Observations in drill core and in the field will be linked to experimental data to help understand processes ranging from ore mineral zoning to replacement reactions.

Days 3 and 4: Analyzing Rocks, Minerals and Fluids in Hydrothermal Systems ( Oct 23 & 24 )
Exploration companies routinely employ commercial laboratories that can analyze the entire periodic table of elements in rocks and minerals, but how can you use all of that data to improve the search for ore? What techniques should be applied to answer specific questions about fluid-rock interaction and ore formation? How can these different methods be used to trace the behaviour of hot aqueous fluids in the crust and the geochemical evolution of those fluids in ore-forming systems. The first day will examine analytical methods relevant to understanding water-rock interaction and the physical and chemical properties of different ore fluids. Key questions that will be addressed include what different methods should be used for different applications (atomic absorption, ICP-MS multielement techniques, XRF), sample handling and sample preparation techniques (e.g. different digestions, sequential leaching) and their relevance to different exploration approaches (WR geochemistry, mineral chemistry, hydrogeochemistry). The second day will examine how to use geochemical data on rocks, minerals and fluids to “fingerprint” different ore-forming processes. We will examine characteristics of different types of fluids responsible for hydrothermal ore deposits (surface water, connate water, metamorphic water, magmatic water) and their physical and chemical properties, with an emphasis on H2O-NaCl-CO2 systems. We will discuss what factors influence the performance of different fluids as ore-forming solutions, including acidity, pressure, temperature, and oxidation states, how different fluids are derived (e.g., through processes of phase separation, fluid mixing, and exsolution from magmas), and how these fluids act under different P-T conditions, with examples from active volcanoes on land and in submarine hydrothermal systems.

Days 5 and 6: Fluid-Rock Interaction and Processes of Hydrothermal Alteration ( Oct 25 & 26 )
Hydrothermal ore deposits are the end products of focusing fluids through porous and permeable media, which results in a wide range of fluid-rock interactions. The site of ore deposition may be proximal to the source of the fluids, as in magmatic-related deposits, or distal, as in the case of mesothermal gold or MVT deposits. Thus, fluids may react with rocks at very high temperatures or may have travelled at much lower temperatures through many tens of kilometers of rock (and potentially hundreds of cubic kilometers). This leads to a bewildering range of ore deposit types and alteration assemblages from SEDEX and uranium to VMS, porphyry and epithermal systems. This part of the course will explore how multidisciplinary approaches to the study of hydrothermal alteration are required to fully characterize the complex evolution of the ore-forming fluids in different settings, recognizing that the rocks are not just a source of ore elements but also determine the kinds of fluids that are produced and dictate the mineralizing processes. The first day will examine the reactions that take place between fluids and rocks, building on the understanding of ore fluid compositions, mineral stabilities, and how fluids behave in hydrothermal systems. This will include a review of alteration at a basic level, integrating field work and observations at the outcrop scale and in drill core with petrography, SEM-EDS applications, and isotopic studies to unravel processes of hydrothermal alteration. The emphasis will be on water-rock interaction and reaction pathways, in particular identifying the channelways for fluids and especially the direction in which they flowed (e.g., through mineral zoning and replacement), as a fundamental guide in mineral exploration. The second day will focus on examples of fluid evolution and alteration in volcanic and sedimentary ore systems as well as magmatic-hydrothermal systems and the relationship between different fluid types and magma evolution.

Days 7 and 8: Examples from Porphyry, Epithermal, VMS, and Orogenic Au Systems ( Oct 27 & 28 )
This final 2-day session will apply the principles of hydrothermal geochemistry and fluid evolution to the interpretation of a number of case studies of porphyry, epithermal, volcanic-hosted massive sulfide, and orogenic Au deposits. The lectures will address a fundamental question: if hydrothermal fluids are so common in the crust, why are the deposits so scarce? The emphasis will be on application of the mineral systems approach to address key questions about different oreforming systems: what were the sources of the metals, what drove hydrothermal fluids through the crust, where did the fluids become trapped, and what caused the deposition of the ore minerals? The first day will focus on ore deposits in subaerial volcanic arcs, drawing from examples of major porphyry and epithermal deposits to constrain the path of the most productive hydrothermal fluids and to understand the size and diversity of the deposits produced. The second day will focus on hydrothermal ore deposits associated with submarine volcanism and with complex regional tectonic and structural systems responsible for orogenic Au deposits. A focus will be on the role of synvolcanic intrusive systems as a trigger for large-scale hydrothermal activity and a probable source for some of the metal content of the deposits. The discussion will draw on lessons from the compositions of the ore fluids, their links to the lithogeochemistry of host rocks, alteration mineralogy and ore mineralogy, and the interpretation of these data to understand what caused the release of large volumes of metalliferous fluid from underlying magmas, from leached volcanic rocks, and from ore-related metamorphic assemblages.

Presenters
  • Mark Hannington is Professor of Economic Geology and Goldcorp Chair in the Department of Earth and Environmental Sciences at the University of Ottawa. He obtained his M.Sc. and Ph.D. at the University of Toronto (1989) and spent 15 years as a research scientist at the Geological Survey of Canada before moving to the University of Ottawa in 2005. His research combines the study of active volcanoes on the ocean floor and associated metal-depositing hot springs ("black smoker vents") with research on ancient volcanic environments that host VMS deposits. He has participated on 24 research cruises to active submarine volcanoes on the East Pacific Rise, Juan de Fuca Ridge, Mid-Atlantic Ridge, Mediterranean, Iceland, New Zealand, Antarctica, and Papua New Guinea. He has also conducted major research projects on VMS, including the giant Kidd Creek deposit, the gold-rich LaRonde deposit, and regional-scale hydrothermal alteration in the Noranda district. Dr. Hannington was editor of the journal Economic Geology from 2001 to 2008.
  • Matthew Leybourne is Associate Professor of Geochemistry in the Department of Earth Sciences at Laurentian University. He is a graduate of the University of Waikato in New Zealand and the Acadia University, and he received his PhD from the University of Ottawa. He started his career working on the hydrogeochemistry of surface waters in the VMS environment, in the Mineral Resources Division of the Geological Survey of Canada, before taking a position as Assistant Professor of Geochemistry at the University of Texas in Austin where he established a new ICP-ES/MS and IC geochemical facility. In 2006 he moved to New Zealand, where he was Senior Scientist at GNS responsible for fluid geochemistry of active submarine hydrothermal systems. He established a new IC-MS laboratory at GNS and was Object Leader in NZs offshore minerals program. In 2012 he moved back to Canada to become the Senior Geochemist at ALS Minerals in Vancouver, where he provided technical and scientific leadership in method development and applications. His diverse career has made him one of the leading experts in Canada on geochemistry applied to mineral exploration and the interpretation of hydrothermal ore deposits.
  • Daniel J. Kontak is Professor of Economic Geology and Chair of Earth Sciences at Laurentian University. He obtained a B.Sc. at St. Francis Xavier University in Nova Scotia and studied the metallogeny of uranium in the Central Mineral Belt of Labrador for his M.Sc. (1980) at the University of Alberta. He completed a Ph.D. at Queen's University in 1985 on the metallogeny of granite-related mineral deposits in the Andes. From 1986 to 2006, Prof. Kontak was the leading economic geologist with the Nova Scotia Department of Natural Resources, where he worked on a variety of mineral resource projects, including granite Sn‑W‑Ta‑base metals, pegmatite Ta‑Li, metamorphic and intrusion related Au, VHMS, porphyry Cu‑Mo‑Au, carbonate Zn‑Pb‑Ba, and industrial minerals (barite, zeolites). He joined the faculty of Laurentian University in 2006. His research interests span the geological setting of base and precious metal deposits with an emphasis on integrating field and laboratory studies to unravel the nature and origin of the mineralizing environment, from regional to local scales, including geochronology, petrology, stable and radiogenic tracers, whole rock and mineral chemistry and fluid chemistry. He serves in many roles in the geoscience community in Canada, including Past President of the Mineralogical Association of Canada.
  • Richard Goldfarb (Consultant)
  • Jeremy Richards (Laurentian)
  • David Burrows (Vale)
  • J. Bruce Gemmell (CODES)
  • Steve Piercey (Memorial University)
  • Robert Seal (USGS)
Costs and Registration

Prerequisites

Advanced undergraduate level (3rd or 4th-year) courses in geochemistry, petrology and ore deposits are strongly recommended. For students without prerequisites, permission from the course administrator is required.

Course Materials

A complete set of notes and related course material will be provided for each 2-day session of the course. These will form the basis for daily problem sets and practical exercises, and a final take-home exam.

Course Format and Evaluation

Students registered in the course will be evaluated on the basis of problem sets/exercises administered at the end of each day (60% of the final mark) and a final take-home exam based on lecture materials and reading related to the course (40% of the final mark). Time will be allocated at the end of each day to discuss materials presented in the class and assist with problem sets. The take-home exam will be due 1 week after the end of the course (November 4, 2017).

Professional Development

The course is applicable toward continuing education and professional development requirements for Professional Registration.

Costs

The student fee is $ 50 for a two-day session ($ 75 after August 21) and $ 200.00 for the full course ($ 300.00 after August 21). Fees for professional participants are $ 500 for a 2-day session.
 

End of pre-registration: August 21, 2017

Registration

Please contact Sarina Cotroneo to get the registration form.

Sarina Cotroneo,
Department of Earth Sciences,
University of Ottawa,
25 Templeton Street,
Ottawa, Ontario, K1N 6N5
Tel: +1 (613) 562-5292
Fax: +1 (613) 562-5192

Email

For payments by credit card, please use our online store

Graduate Student Credit and Registration

This course will correspond to University of Ottawa GEO 5306 and Laurentian University GEOL 5607 (3 credits). Students must attend the entire course for full credit. Students from any university are eligible to take the course. Students enrolled at ONTARIO universities wishing to transfer credit for this course to their home institution must complete an Ontario Visiting Graduate Student (OVGS) form. Contact your academic unit or your Graduate Studies office for the form. Students at NON-ONTARIO universities or those not registered in the OVGS program may receive credit from their home institutions, but you are responsible for obtaining the approval and credit from your own Department. Students at NON-ONTARIO universities (Canadian and non-Canadian) wishing to receive an official transcript from the University of Ottawa must be admitted to the University of Ottawa as Special Students and registered Part-Time. Please contact us by email for more information. All students will receive a letter from the course instructor indicating successful completion of the course and a course mark, where appropriate. However, only those students registered with the Ontario Visiting Graduate Student Program or as part-time students at the University of Ottawa will receive an official transcript. Other students are encouraged to discuss obtaining credit for this course with their home Departments.

Location and Services

Lectures will be held in the Faculty of Social Sciences Building on the University of Ottawa Campus. Surface and underground pay parking is available on the campus. The course has been scheduled during Reading Week, so some services may not be available. Information on local accommodations is available by email.

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