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Lothian geology: an excursion guide
Edition 4, 2026
Development of this new guide is in progress.
Contents
Preface
The landscape of Edinburgh and Lothian is a remarkable record of Scotland’s past. From the rocky heights of Arthur’s Seat and the Pentland Hills to the broad agricultural plains, dramatic coastlines and islands of the Firth of Forth, the region contains an extraordinary variety of geology and scenery within a relatively small area. Look closely at the hills, cliffs, quarries and coast, and it becomes possible to read a story that stretches back hundreds of millions of years.
The rocks beneath our feet were not formed here in the landscape we see today. They were created in very different environments, over hundreds of millions of years. Some formed from volcanic eruptions, when ancient volcanoes dominated the landscape. Others accumulated as layers of mud, sand and gravel in rivers, lakes and shallow seas when the area was closer to the equator. The region has been shaped by movements of the Earth's crust, which folded and faulted the rocks, while later erosion formed the hills and valleys we recognise today.
Perhaps nowhere is this geological history more obvious than around Edinburgh itself. Arthur’s Seat, Salisbury Crags and the other hills are the remains of a volcanic past. The durable volcanic rocks survive erosion better than many of the softer rocks around them. Their distinctive forms have helped give Edinburgh its famous skyline. Yet these hills are only part of a much larger volcanic story that extends across Lothian and beyond, with the remains of numerous ancient volcanoes preserved in the landscape. The coastline provides another window into the past. In addition, high quality exposures in cliffs and platforms around the shores of the Firth of Forth allow us to see strata and structures that are hidden inland.
The landscape we see today, however, is not simply the result of the rocks themselves. Much of its present character was created during the most recent Ice Age. On several occasions over the last two million years, huge ice sheets spread across Scotland, covering Lothian and flowing through the Firth of Forth. Moving slowly across the land, the ice scraped and smoothed the underlying rocks, deepened valleys and transported enormous quantities of sediment. As the climate warmed and the ice melted away, it left behind deposits of clay, sand and gravel that continue to influence the landscape and soils today.
Geology has also had a profound influence on people. The availability of stone, coal, limestone and other natural resources helped shape the development of settlements and industries across Lothian. Edinburgh itself was built using stone from the surrounding region, and the character of the city’s buildings reflects the rocks on which it stands. Agriculture, too, has been influenced by the underlying geology, through its effects on soils, drainage and the shape of the land. Roads, railways, harbours and other infrastructure have all had to respond to the geological foundations of the region.
This book explores these connections between rocks, landscape and of course people. It is not necessary to be a geologist to appreciate the story. The aim is simply to encourage a different way of looking at familiar places: to see a hill not just as a hill, a cliff not just as a cliff, but as part of a much longer story. A walk through Lothian can become a journey through vanished volcanoes, ancient rivers and seas, shifting continents and advancing ice sheets. The geology of Edinburgh and Lothian is therefore much more than a collection of rocks. It is the foundation of the landscape, a record of environments that existed long before Scotland took its present form, and an important part of the region's human history. This guide provides ideas for half- or single-day excursions that will give the visitor a better understanding of the local geology, the history of the area and the landscape. It builds extensively on the three previous versions of the guidebook, and the present editor is grateful to the editors and authors of these books for their inspiration.