On completion of this module, students should be able to:
1) Use a petrological microscope to describe and identify minerals, interpret textures and perform optical tests.
2) Demonstrate in writing a knowledge of mineralogy and mineral chemistry and how they can be used to determine how rocks formed.
3) Characterise and interpret the texture and composition of clastic sediment and sedimentary rocks.
4) Use sedimentary structures to reconstruct sediment transport processes and environments of deposition, and to identify environmental change.
5) Identify the main components in limestones and relate these to the original depositional setting.

WEEK 1 (13th - 17th SEPTEMBER 2021)
All classes and supporting materials in week 1 will be available online only, as follows:

Lecture 1: Minerals, crystals and polarised light.
Course outline; the nature of ordinary and plane polarized light; optical properties under the petrological microscope in plane polarized light and between crossed polars; crystalline structure, symmetry and the seven crystal systems. Use of the Michel - Levy chart.

Lecture 2: Silicate minerals.
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.

Practical preparation:
Mineral hand specimen description - an introduction to simple properties that can be used to describe and identify hand specimens of minerals: colour, transparency, cleavage and crystal habit (mp4 video)

Practical 1: Description of mineral hand specimens presented online as 3D rotatable images.

Exercise: the Periodic Table – elements, ions, bonding and chemical compounds.
Information and self-assessment related to the Periodic Table – elements, chemical symbols, atoms, ions, ionic charge and radius, co-ordination numbers, chemical bonds and chemical formulae.

WEEKS 2 - 12

LECTURES
Lectures will be held once per week at 11 am on Tuesdays in G01, Science West.

Week 2: during the lecture slot, there will be a short face to face practical class in room G01, continuing the hand specimen description from week 1.

Week 3: Mineral stability and phase diagrams.
Controls on mineral stability and its depiction on phase diagrams; crystal-liquid binary diagrams (anorthite-diopside and plagioclase); eutectic points; the Lever Rule in binary diagrams; polymorphism and the Al2SiO5 polymorphs; alkali feldspar solvus diagram and perthite textures.

Week 4: Igneous rocks.
Crystallization from magmas, volcanic and plutonic, and sequence of crystal growth, with implications for mineralogy and texture of igneous rocks. Controls on element partitioning, fractional crystallization, sequence of crystal growth and Bowen’s reaction series.

Week 5: Metamorphic rocks.
Solid state recrystallization in different temperature and confining pressure environments and implication for the mineralogy and textures of metamorphic rocks.

Week 6: NO LECTURE.

Week 7: Sediment and sedimentary rocks
Types of Sediment and sedimentary rock. Principle depositional processes and environments. Sedimentary Basins. Sediment grain size and texture. Classification of clastic sediments and rocks.

Week 8: Sandstone composition
Sandstone components. Heavy minerals. Composition and sandstone classification. QFL-diagrams. Main controls on sandstone composition. Provenance, source areas and palaeoclimate.

Week 9: Sediment transport and structures under unidirectional flow.
Movement of particles by natural unidirectional flow with low sediment concentrations (e.g., rivers, turbidity currents, pyroclastic flows). Bedforms and associated depositional structures: current ripples, dunes, upper-stage planar lamination, antidunes. Bedform stability fields.

Week 10: Sediment transport and structures under waves and tidal flow.
Movement of particles by oscillating and reversing flows in shallow water settings. Bedforms and associated depositional structures: wave ripples, hummocky and swaley cross stratification, herring bone cross stratification. Evidence for reversing flow and tidal signatures.

Week 11:Carbonate sedimentary rocks
Precipitation of carbonate from seawater. Carbonate factories – past and present. Reefs, mounds and carbonate sands and muds. Main limestone depositional environments. Post-depositional reactions – cements and dolomitisation.

Week 12: NO LECTURE.

ONLINE EXERCISES AND PRACTICAL PREPARATION

Various materials will be available on Brightspace at the start of each week. Some provide information as preparation for practicals, in the form of videos, presentations or text documents. Others consist of online exercises, with self-assessment quizzes, to deepen your understanding of topics recently introduced in lectures.
Week 1

2) The Motic petrological microscope: its parts and their functions. (mp4 video)
3) Mineral thin section description – an introduction to the purpose and methods of describing the optical properties of minerals in thin section (mp4 video).

Week 2


Week 3
Exercise: Silicate minerals – atomic structure and chemical composition.
Information and self-assessment on: silicate polymerization and atomic structures; classification of silicate minerals; the behaviour of aluminium in silicate minerals; element substitution, solid solution chemistry and its graphical representation.
Practical preparation:
How to use the virtual microscope (mp4 video).
How to measure plagioclase composition using the virtual microscope (mp4 video).

Week 4
Exercise: mineral stability and phase diagrams.
Information and self-assessment on: plotting, calculations and interpretations related to phase diagrams, including binary crystal-liquid (anorthite-diopside, plagioclase), solvus (alkali feldspar) and polymorphic pressure - temperature (SiO2, Al2SiO5) examples.

Week 5
Practical preparation: Construction of a mineral identification key for use in the mid-trimester class test.

Week 7
Exercise: Sedimentary rocks of Ireland
Exploration of the bedrock geology. Types and ages of ancient sediments and their depositional environments. Applied and commercial aspects of sediments and sedimentary rocks. The exercise will be self-assessed and will utilise the Geological Survey of Ireland’s online GIS application.

Week 8
Exercise: Sandstones in thin section
The common components of sandstones that can be seen under thin section. Consideration of sandstone physical and compositional texture. The exercise will be self-assessed and will utilise the Virtual Microscope website.

Week 9
Exercise: Basic fluid dynamics and sediment transport theory
Information and self-assessment on: fluid properties, flow rheology, describing fluid flow (steady vs. unsteady flow, uniform vs. nonuniform flow, subcritical vs. supercritical flow, laminar vs. turbulent flow), velocity profiles, particle transport mechanisms, hydraulic boundary layer, threshold of particle motion and suspension.

Week 10
Exercise: Aeolian deposits and bedforms
Sediment transport in aeolian environments, typical characteristic of aeolian deposits (deflation lags, desert varnishing, grain rounding and surficial cements), aeolian bedforms (impact ripples, dunes and draas), internal structure of dunes, dust deposits.

Week 11
Practical preparation: Information on limestone components and limestone classification. Self assessment on identifying and naming limestones using microscope images.

PRACTICAL CLASSES

Practical classes will be 3 hours long at 3.00 pm on Wednesdays in room G01, Science West.
You will be provided with a set of mineral and rock specimens, a practical notebook and various small items of equipment such as pencils, coloured pencils, a hand lens and a stick of glue to fix practical handouts in your notebook. You will also be provided with a microscope and a set of thin sections. Apart from the notebook, all of this is on loan to you and must not be removed from the lab. DO NOT share or exchange any of these items with any other student. In general, no materials should be exchanged with others in the class.

Weeks 2 – 5 (mineralogy)
At the end of each practical class, you should hand up your practical notebook so that you can be given feedback on your work. You should then take care to correct any weaknesses in your work pointed out to you in feedback. This is important because your practical notebook will assist you in the mid-trimester class test.

Week 1: Description of granite minerals in hand specimen and thin section.
Description of granite minerals (quartz, plagioclase, microcline, biotite, muscovite) in hand specimen; introduction to the petrological (polarizing) microscope; description of the properties of minerals in granite in thin section.

Week 2: Description of augite, hypersthene, epidote and hornblende in thin section and hand specimen; how to distinguish between them. Extinction angles of mafic minerals and mineral identification. The use of igneous minerals and textures in understanding the origin of magmas and crystallization of igneous rocks.

Week 3: Description of olivine, serpentine, magnetite and garnet in thin section and hand specimen. Introduction to the virtual microscope. Plagioclase composition determination using the virtual microscope.

Week 4: Description of andalusite, kyanite, sillimanite and chlorite in hand specimen and thin section. The use of metamorphic minerals and their textures in understanding metamorphic history.

Week 5: Description of calcite, aragonite and dolomite in hand specimen and of calcite and dolomite in carbonate sedimentary rock. Description of orthoclase in hand specimen and thin section. Description in thin section of coarse sand and comparison with the same minerals in granite.

Weeks 7 – 11 (sediments and sedimentary rocks)
Week 7: Quantification of grain size using simple statistics to describe modern and ancient sediments. Evaluation of grain size variations in rivers. Use of Excel to automate calculations and graphing.

Week 8: Description of sandstones in hand specimen and in thin section. Sorting and grain rounding and link to depositional processes. Porosity and compaction fabrics. Cement and style of distribution. QFL classification.

Week 9: Exploring sediment transport and bedform development using flume experiments. Open channel flow and turbidity current experiments. Bedload vs. suspended load. Bedforms formed by open channel flow.

Week 10: Deriving flow direction from sedimentary structures and plotting directional data. Azimuthal vs. lineation data. Rose diagrams. Circular statistics. Variation in flow direction in natural river systems.

Week 11: Limestone depositional environments and environmental change based on sedimentary structures, hand specimens and thin-sections.

Not applicable to this module.

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

The first half of the module is assessed by a mid-trimester class test, to be held in room G01, Science West. It consists of two parts: 1) short-answer questions on theory and 2) microscope-based exercises to test ability to describe and identify minerals. Mid-trimester test: 3.00 pm, Wednesday 20th October, for 90 minutes – 50% of module credit. You will be allowed to consult your laboratory notebook during the microscopy part of the mid-trimester test. The second half of the module will be assessed by an end-trimester class test, to be held in room G01, Science West, and will again comprise two parts: 1) short-answer questions on clastic and carbonate sedimentary rocks, and 2) a practical exercise in which you will describe and interpret a sedimentary succession. End-trimester test: 3.00 pm, Wednesday 1stDecember, for 90 minutes – 50% of module credit. This will be a closed book test.