Prerequisite: GY201, GY229
Course status: Core
Credit Rating: 12 credits
Total hours spent: 120 hours [45 hours lectures, 30 hours Practicals, 15 hours Assignments, and 30 hours independent study]
Course Objective(s)
o To give students an understanding of igneous rocks’ texture, mineralogical compositions and their applications in igneous rocks petrogenesis and classifications.
o To give insights on magmatic processes operating in different tectonic settings using mineral associations and chemical compositions.
Learning Outcomes
By the end of this course, students should be able to:
o Identify and classify igneous rocks
o Describe magmatic processes in their tectonic setting using mineral association, composition of major and trace elements and isotopes, and simple phase diagrams.
Course Structure
Introduction to Petrology; Magmatic Petrology Processes; Igneous rocks and their classifications; Mineralogy of Igneous rocks; Generation and evolution of magmas; Harker and AFM plots; Partitioning of trace elements.
Course Content
Origin, cooling and crystallization of magmas: magmatic fraction processes; intrusive rocks, shape and size of igneous rock fabric and texture, phanaretic and aphanitic and glass rocks; essential and accessory minerals in igneous rocks, classification of igneous rocks, colour index. Cumulate and non-cumulate rocks. Mineralogical and textural characteristics of common igneous rock types including peridotite, gabbro, and granite and their extrusive equivalents. Igneous rock associations and plate tectonics; Generation and evolution of magmas: batch and fractional melting; magmatic series; tholeiitic, calc-alkaline, alkalic and peralkaline magmas; chemical variation diagrams. Harker and AFM plots; Fractionation indices. Construction of phase diagram: Lever rule; Phase diagrams for binary, ternary, and quaternary magmatic model systems. Eutectic and peritecti reactions; phase equilibria involving solid solution, congruent and incongruent melting; Liquidus projections and isothermal sections; Alkemade Theorem and Triangles. Partitioning of trace elements during equilibrium partial melting and magmatic crystallization; Partition coefficients (KD); Uses of trace elements in igneous petrogenesis.
Assessment
Coursework 40%, Final Examination 60%.
Reference Textbooks:
1. Best, M.G. (2013). Igneous and Metamorphic Petrology. J. Wiley and Sons.
2. Philpotts, A.R. and Ague, J. (2009). Principles of Igneous and metamorphic Petrology. Cambridge University Press.
3. Winter, J.D. (2013). Principles of Igneous Petrology. Pearson Education.
4. Frost, R.B. and Frost, C.D. (2014). Essentials of Igneous and Metamorphic Petrology. Cambridge University Press.
5. Philpotts, A.R. (2003). Petrography of Igneous and Metamorphic Rocks. Waveland Press.