Topic 9: The Caledonian Mountains

We’ll follow the stories of Laurentia, Avalonia, and the Iapetus Ocean with the history of the Caledonian mountains, an enormous mountain range which once stretched across Ireland and beyond, from what’s now the Appalachian Mountains of the USA in the west, as far as Norway in the east. We’ll cover how those mountains formed, and where they are now. We’ll also have a change from looking at rocks to examine some sediments from different environments.

Lecture

Lecture slides: L9 Caledonian

Reading

I suggest reading Chapters 11 and 16 of Lutgens and Tarbuck 2015 Essentials of Geology. Chapter 11 is the chapter on Crustal Deformation and Mountain Building, and it will help you to understand what was happening during the events described in the lecture. Chapter 11 is the chapter on Deserts and Wind, and it will help you to understand what Ireland was like during the Devonian Period.

I would also suggest reading Chapters 5-7 of Understanding Earth Processes Rocks and the Geology of Ireland by Sleeman et al. These are the chapters on Silurian rocks in Ireland, the Caledonian Orogeny, and Ireland in the Devonian Period, and so will more directly expand on what we cover in the lecture.

Additional

One of the impacts the Caledonian Orogeny is still having on society might be a bit unexpected: specifically, the impacts on health. Radon gas escaping from granites (though granites are not the only source) is a significant cause of lung cancer in Ireland and around the world. This paper by Appleton, J.D. 2007 Radon: Sources, Health Risks, and Hazard Mapping. Ambio 36, 85-89 provides a short introduction to the topic (which will be mentioned again).