The Field Description of Igneous Rocks, 2nd Edition

1 Introduction and Occurrence.

1.1 The Importance of Fieldwork.

1.2 The Global Picture – Igneous Rocks in Relation to Regional Tectonics.

1.3 Mode of Occurrence of Igneous Bodies.

1.4 Summary.

2 Field Skills and Outcrop Structures.

2.1 Equipment.

2.2 Preparing Maps and Basic Mapping.

2.3 Notebooks and Data Recording.

2.4 Primary Outcrop Structures.

2.5 Secondary or Late Stage Outcrop Structures.

2.6 Outcrop Contact Relationships.

2.7 Summary of Igneous Outcrop Descriptions.

3 Igneous Textures and Classification.

3.1 Describing Rock Types.

3.2 Colour and Composition.

3.3 Texture, Grain-Size/Shape and Fabric.

3.4 Mineral Identification.

3.5 Naming and Classification.

4 Volcanics 1 – Lava Flows.

4.1 Lava Flow Emplacement Mechanisms.

4.2 A Compositional Divide for Lava Flows.

4.3 Mafic/Basaltic Lava Flows.

4.4 Felsic/Silicic Flows.

4.5 Pillow Lavas and Hyaloclastites.

5 Volcanics 2 – Pyroclastic Rocks.

5.1 Structures, Textures and Classification.

5.2 Pyroclastic Flows and Ignimbrites.

5.3 Scoria Cones.

5.4 Water/Magma and Sediment/Magma Interactions.

5.5 Epiclastic Deposits.

6 Shallow-Level Intrusions.

6.1 Sill and Dykes.

6.2 Working Out Emplacement History.

6.3 Volcanic Plugs and Diatremes.

6.4 High-Level Subvolcanic Intrusions.

7 Granitic Complexes.

7.1 Introduction.

7.2 General Features and Occurrence.

7.3 Zoned Plutons.

7.4 Internal Structures and Textures.

7.5 Internal Contacts.

7.6 Emplacement Timing.

7.7 Distinctive Granitoid Textures.

7.8 Metamorphic Aureoles.

7.9 Summary of the Field Characteristics of Granitic Complexes.

8 Mafic Complexes.

8.1 General Features and Occurrence.

8.2 Continental Mafic-Ultramafic Intrusions.

8.3 Ophiolite Complexes.

8.4 Komatiites.

8.5 Summary of the Field Characteristics of Mafic-Ultramafic Intrusions.

9 Magma Mixing and Mingling.

9.1 Magma Rheology.

9.2 Magma Mixing.

9.3 Magma Mingling.

9.4 Synplutonic Dykes and Sills.

9.5 Magma Mingling in Subvolcanic and Volcanic Environments.

9.6 Xenoliths.

9.7 A Word of Warning.

9.8 Summary.

10 Mineralisation and Geotechnical Properties.

10.1 Mineralisation and Key Minerals.

10.2 Mineralisation in Layered Mafic Intrusions.

10.3 Geotechnical Properties of Igneous Rocks.

10.4 Rock Mass Classification.

10.5 Summary.

Appendix.

Further Reading.

Index.