Transcript LECTURE W1-L1 - Introduction

Igneous
Petrology
Jean-François
Moyen
Lecturer
• Jean-François (Jeff) Moyen
• Contact details:
– 021 808 3126
– [email protected]
– Room 2039 or somewhere else (8:30-17:30)
Class timetable
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Monday 10.00 – 11.00 am (L)
Tuesday 8.00 – 9.00 am (L)
Friday 11.00 – 12.00 am (L)
Wednesday 14.00 – 17.00 pm (P)
• Venues: … depend on the construction
work!
Course content
• Tools used to study igneous rocks
• Magmatic processes from melting to final
emplacement and cooling
• Some important types of igneous rocks
(e.g., mid-ocean ridge basalts, granites,
arc magmas, etc.)
And also…
• Scientific approach to geological problems
– Observe
– Interpret
– Conclude
• Writing of scientific texts (structured,
rigorous)
• Autonomy
– Seek different sources of information
– Work from general instructions and device
your own way to the solution
Textbook
Winter, J.D. An introduction to igneous
and metamorphic petrology. Prentice
Hall, 2002 (also used for Geol 354)
Lecture notes etc.
http://academic.sun.ac.za/geology/undergraduate
/modules/geol314_e.htm
Assessment
• Course mark 40%
– Pracs (12 x 5 %) = 60%
– Field report 20%
– Paper presentation 20%
• Exam mark 60%
– Open book exam
– Based on documents to comment
Practicals
• To be handed in at the latest on the next
Monday
• I will try to mark them for the following
session (Wednesday)
Field work
• One prac will be a field-based exercise
(Sea Point)
• Two days field trip
on the West Coast
(Cape Columbine)
during April break –
date to be defined
(please think about it)
Paper presentation
• Each student will read, understand and
summarize one research paper of
importance
• Presentation will consist of
– A 1-page handout for the class
– A 10 mn oral presentation (+ questions)
• Papers presentations are part of the
course – aspects dealt with during
presentations will not be repeated
A last word
(before we start the real things)
• Please make this course interactive!
• Questions are always welcome and never
stupid
• Some parts are more difficult than others
(and the first weeks are not the easiest…)
Igneous rocks
(magmatic rocks)
• Rocks formed from a magma
• Magma = melt+crystals+bubbles
• More or less obvious
Stromboli (Italy)
Etna (Italy)
Piton de la Fournaise (Réunion, Indian Ocean)
Ploumanac’h, France
Torres del Paine, S. Chile
Cantal extinct volcano, France
« Ignimbrites », Turkey
Bournac volcanic pipe, France
Montserrat, Lesser antilles (1997)
Partially
molten rocks
= migmatites
Solidus and Liquidus
Fractional crystallisation
Figure 4-21. Kangâmiut dike swarm in the Søndre Strømfjord region
of SE Greenland. From Escher et al. (1976), Geology of Greenland,
© The Geological Survey of Denmark and Greenland. 77-95.
Ploumanac’h, France
Torres del Paine, S. Chile
a
Structures
and Field
Relationships
Figure 4-32. Developmental sequence
of intrusions composing the Tuolumne
Intrusive Series (after Bateman and
Chappell, 1979), Geol. Soc. Amer. Bull.,
90, 465-482. a. Original intrusion and
solidification of marginal quartz diorite.
b. Surge of magma followed by
solidification of Half Dome Granodiorite.
c. Second surge of magma followed by
solidification of porphyritic facies of Half
Dome Granodiorite. d. Third surge of
magma followed by solidification of
Cathedral Peak Granodiorite and final
emplacement of Johnson Granite
Porphry.
b
N
Magma
Magma
Marginal quartz diorite
Half Dome granodiorite (non-porph)
Cathedral Peak granodiorite
Half Dome granodiorite (porphyritic)
Johnson granite porphry
10 kilometers
c
d
Magma
The Peninsula
Range Batholith
(California/Mexico)
Volcanoes feeder complexes
Sub-volcanic Ring Dyke
Piton des Neiges Volcano (extinct), Réunion Isl.
Stromboli (Italy)
From formation to emplacement
What do we have to study?
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Melting
Magma transfert
Magma evolution
Emplacement (plutons, or volcanoes)
Final cooling
… and plate tectonics context
Plate Tectonic - Igneous
Genesis
1. Mid-ocean Ridges
2. Intracontinental
Rifts
3. Island Arcs
4. Active Continental
Margins
5. Back-arc Basins
6. Ocean Island Basalts
7. Miscellaneous IntraContinental Activity

kimberlites, carbonatites,
anorthosites...
Course outline
1. Introduction, background
2. What is a rock made of? Major elements,
magmatic series, etc.
3. Melting
4. Magma differenciation and evolution
5. How to identify which process operated?
Some geochemistry.
6. Cooling and solidification of magmas
7. Emplacement of plutons
8. Volcanoes
9. Granites
10. Ophiolites and mid-oceanic ridges
magmatism
11. Layered igneous complexes
12. Arc magmas
13. Intraplate magmatism
14. Archaean magmatism