Building stone and Devon’s geology

Building stones of County Hall – A trail through geological time

Use the links below to access a guide which explains the interesting building stones which were used in the construction of County Hall, which is the headquarters of Devon County Council in Exeter.

In 1998, County Hall was listed Grade II* and in the listing notice it was highlighted that the building was constructed with quality materials. This guide, in the form of a trail, leads you to some of the best examples of the attractive buildings stones on site and explains the geology behind the materials.

Evidence of environments which are millions of years old can be seen in the stones which construct County Hall and using this guide you can find fossils and clues which indicate the setting which the rocks were formed in.

The guide to the building stones of County Hall comes in two formats:

  1. A leaflet version of this guide provides an introduction to the building stones with an explanation of any geological terms used.

Leaflet on the building stones of County Hall

2. A more expanded version of the guide has also been produced, which contains more technical detail for those with a particular interest in geology.

Technical guide to the building stones of County Hall

Access to County Hall and around the trail

The trail is only suitable for staff at County Hall and their visitors with planned visits.  The trail around County Hall is all on the first floor except at stage 9, at the Grand Stairs. To access this point there is a lift available, which can be found behind the large granite commemorative stone highlighted in stage 8 of the trail.

Exeter Cathedral’s geology

Exeter Cathedral is magnificent and some have claimed that it possesses the most varied geology of any British cathedral. Materials from over 20 different quarries, many of them local, were used in its construction. The outer and inner Cathedral walls are made of Salcombe Stone, a sandstone quarried from Salcombe Regis in East Devon. Between these walls is a loose filling of the same volcanic trap (lava) quarried two miles west of the river Exe, also used in the construction of the City walls. Chalk mines at Beer, also on the east coastof Devon, were worked to provide stone for use in some of the Cathedral’s sculptures, which can be seen on the impressive image screen at the front of the building.

More local geology can be seen inside the Cathedral. For example, the pillars supporting the Patteson Pulpit are made of a Devonian limestone that can take a polish. This rock has been deformed by the earth’s movements, such that some of the corals within it appear elongated. It can be found at a number of sites in south west Devon. Follow a geology trail around the cathedral in the information leaflet Geology of Exeter Cathedral.

Exeter Cathedral