GEOL40190 Igneous Petrology and Ore Geology

Academic Year 2022/2023

The module examines the causes of magma generation, magma evolution and igneous rock formation in a variety of both modern plate tectonic settings and ancient, less well-understood, tectonic settings. It also deals with a number of major types of metallic mineral deposit though study of well-researched examples. The intention is to gain an understanding of current research in these areas and to be able to compare and evaluate competing hypotheses through critical reading and discussion of research publications and through petrographic examination of igneous rocks and mineralized rocks.

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Curricular information is subject to change

Learning Outcomes:

1. Critically evaluate, both orally in seminars and in written work, research articles on a variety of topics in igneous petrology and ore geology.
2. Plot, manipulate and carry out calculations on geochemical and isotope data and draw conclusions about the origin and evolution of magmas.
3. Make detailed petrographic descriptions of igneous rocks and from these descriptions draw conclusions on the origin, evolution and crystallization of these rocks.
4. Make detailed petrographic descriptions of mineralized rocks and from these descriptions draw conclusions on the mineralizing processes involved.

Indicative Module Content:

Igneous Petrology – 6 x 4 hour sessions including lectures, seminars and practical work

1 Komatiites (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on petrogenesis including the question of magma water content, tectonic setting and conditions of crystallization; practical on description and interpretation of komatiites in thin section from Munro Township, Ontario.

2 Anorthosite-mangerite-charnockite-granite (AMCG) magmatism (Assoc. Prof. J.F. Menuge)
Silicate composition of crust and mantle; The SiO4 tetrahedron, silicate polymerization and silicate classification, with examples of each class; Goldschmidt's rules, chemical substitution and solid solution; examples of silicate solid solutions; relationships between silicate properties and silicate classification.

3 Lunar igneous petrology (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on the sources of information on lunar igneous petrology, the origin of the Moon, its early differentiation and mechanisms generating lunar basalts; practical based on description and textural interpretation of NASA lunar thin sections.

4 Mid-ocean ridge basalts (Prof. P.F. McDermott)
Mantle melting at constructive plate margins. Mantle upwelling, melting columns sampling of heterogeneities. Influence of spreading rates, lithosphere thickness and regional temperature anomalies. Mechanisms of magma differentiation. Magmatic products and thermal/thickness evolution of oceanic crust. Insights from very slow spreading centres (SWIR and Gakkel). Workshop/debate on the petrological significance of global correlations in the major element composition of mid-ocean ridge basalts (Klein and Langmuir versus Niu and O’Hara).

5 Destructive plate margin (Prof. P.F. McDermott)
Subduction of oceanic crust and dehydration reactions. Fate of subducted slabs and sediments. Temperature profile through a subduction zone. Influence of volatiles on mantle solidus. Volatile transport into mantle wedge. Rates of wedge convection, replenishment and depletion. Magmatic products and their distinctive geochemistry. Data analysis practical using Excel to do basic calculations and plot data. Interpretation of trace element ratio vs. isotope ratio correlations.

6 Intra-plate magmatism (Prof. P.F. McDermott)
Oceanic intra-plate magmatism. Ocean island basalts, their petrology and geochemistry. Initiation and evolution of mantle plumes. Asthenospheric and lithospheric contributions to magmatism. The nature and causes of mantle heterogeneity. Geophysical and geochemical evidence for heterogeneity on a range of scales. Preservation of heterogeneities. Links between ocean island magmatism and flood basalt provinces. Student presentations on recent review papers on the geophysical and geochemical constraints on the nature of the Earth’s mantle. Models for mantle structure and convection.

Ore Petrology – 5 x 4 hour sessions, including lectures, seminars lab work, and a one-day field class.

1 The Navan Zn-Pb ore deposit, Co. Meath (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on the geological setting of the Navan deposit, the origin of fluid and dissolved materials, the role of faults, processes of ore precipitation and the timing of mineralization; practical introduces reflected light microscopy, followed by description and interpretation of Navan Zn-Pb ore in polished thin section.

2 Stratiform sediment-hosted base metal deposits (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on the role of redox reactions, timing of mineralization relative to deposition, diagenesis and faulting in both the Kupferschiefer and the Central African Copperbelt; practical on description and interpretation of Cu sulphide ore from Chibuluma, Zambian Copperbelt in polished thin section.

3 Porphyry ore deposits (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on the relationship of mineralization to host intrusions, chemical partitioning between magmas and hydrothermal fluids, the relationship between hydrothermal alteration and mineralization, and processes leading to ore deposition; practical on description and interpretation of Los Pelambres porphyry copper ore, Argentina in polished thin section.

4 Iron oxide apatite (IOA) and iron oxide-copper-gold (IOCG) ore deposits (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on arguments for hydrothermal vs magmatic Fe oxide ores, models for origin of fluids and dissolved constituents in IOCG deposits, age relationships relative to host igneous rocks and the tectonic settings of IOCG mineralization; practical on description and interpretation of Fe oxide-P-REE ores of Pea Ridge, southeast Missouri in ordinary and polished thin section.

5 Magmatic Ni-Cu-Co-PGE ores (Assoc. Prof. J.F. Menuge)
Lecture and seminar focusing on magmatic processes leading to sulphide mineralization in the Sudbury and Noril’sk District intrusions, including sulphide liquid PGE enrichment and sulphide enrichment processes; practical on description and interpretation of Ni-Cu ores of Sudbury, Ontario in polished thin section.

6 If possible under Covid-19 restrictions, field class to Boliden Tara Mines
This one-day class is led by Tara Mines geological and mineral processing staff, accompanied by Assoc. Prof. Julian Menuge, and consists of:
1. An introductory lecture on the discovery of the deposit, its geological setting and an overview of the mine.
2. A visit to several underground localities that illustrate types of ore and host rocks, as well as some of the mining practices.
3. A visit to the mill, to see the various crushing, grinding, flotation and other processes involved in producing zinc and lead concentrates for export.
4. Brief examination of drill core recently extracted during mineral exploration in and around the mine.

Or, if the Tara Mines field class is not possible, we will have a 4-hour session on the platinum group element ores of the Bushveld Complex, South Africa,.

Student Effort Hours: 
Student Effort Type Hours
Lectures

11

Seminar (or Webinar)

8

Practical

25

Field Trip/External Visits

7

Specified Learning Activities

22

Autonomous Student Learning

27

Total

100

Approaches to Teaching and Learning:
Students will learn through a range of methods designed to reinforce each other. These include a series of lectures, seminars and practical classes, the last examining rock hand specimens and thin sections as evidence of petrogenetic and metallogenetic processes. Lectures and research publications will form the basis for student-led seminars and for students' written summaries of research. As far as is allowed by Covid-19 regulations, classes will be given face to face, but some may have to be provided online. 
Requirements, Exclusions and Recommendations

Not applicable to this module.


Module Requisites and Incompatibles
Pre-requisite:
GEOL30240 - Igneous Petrology, GEOL30380 - Geomaterials and Geoenergy

Incompatibles:
GEOL40280 - Petrology & Ore Geology


 
Assessment Strategy  
Description Timing Open Book Exam Component Scale Must Pass Component % of Final Grade
Continuous Assessment: Continuous assessment of practical work. Throughout the Trimester n/a Standard conversion grade scale 40% No

25

Examination: Two-hour written exam. Week 12 No Standard conversion grade scale 40% No

50

Examination: Two-hour practical exam on igneous and ore geology. Week 11 No Standard conversion grade scale 40% No

25


Carry forward of passed components
Yes
 
Resit In Terminal Exam
Spring Yes - 2 Hour
Please see Student Jargon Buster for more information about remediation types and timing. 
Feedback Strategy/Strategies

• Feedback individually to students, on an activity or draft prior to summative assessment
• Feedback individually to students, post-assessment
• Group/class feedback, post-assessment

How will my Feedback be Delivered?

Students will receive individual written feedback on work that has been graded for continuous assessment, supplemented by oral feedback to the whole class, and this will also act as feedback prior to the end of trimester practical exam. Discussion with individual students and the whole class during seminars and practical classes will include feedback given prior to assessment.

Name Role
Professor Frank McDermott Lecturer / Co-Lecturer