Geology of Wenlock

Shropshire's Geology is very diverse. The county has over 300 geologically important sites containing a great variety of rocks and fossils dating back over 660 million years. Rocks representing most of the geological periods represented in the British Isles can be found here. This varied geology has provided a wealth of resources including lead, coal and iron.

The rocks of Shropshire originated in a variety of environments including deserts, volcanoes, coral reefs, tropical forests and glaciers. Geologists divide the vast history of the Earth into geological periods of time. These divisions are not random and do not represent equal portions of time. Instead they are points at which there have been major changes such as extinctions of life, changes in climate, continents colliding or oceans forming.

The term Silurian is used for the period from 444 to 416 million years ago. It was created by one of the most famous of Victorian geologists Sir Roderick Murchison, who first used the term in 1835.

In his book, the Silurian System, he described the then little-known rocks of the Welsh Borders including Shropshire, in which he found a wonderful variety of fossils. Murchison described the various rock sequences with their distinct fossils, many of which had not been seen before. Murchison subdivided his Silurian rocks into a number of small rock divisions and two of these, the Wenlock Series and Ludlow Series, were based on his studies of the rocks sequences around Much Wenlock and Ludlow in south Shropshire. These two terms are now internationally recognised subdivisions of the Silurian Period.

We now know that the Silurian rocks of Wenlock Edge were formed when this area lay about 5,000 miles south of its present position. Britain, along with parts of Europe and Asia continue to drift northwards at a rate of 2cm a year.


Seen from the air, Wenlock Edge stands out as the major feature of the South Shropshire landscape – a limestone ridge running some 18 miles from Ironbridge to Craven Arms. This ridge is a natural feature of considerable scientific importance.

Shropshire’s stunning scenery reflects its geological past. Rocks resistant to erosion have been folded and faulted to form the hills we see today. The less resistant rocks have been eroded away to form valleys. Shropshire is also a county well known for its rich variety of fossils and it has many internationally important sites including Wenlock Edge, Whitcliffe, Grinshill and Clee Hill.

Wenlock Edge is one of a series of linear hill ridges in South Shropshire running northeast to southwest. It is the geology of Wenlock Edge that has created this distinctive landscape, {which has contributed towards]which, for the past 50 years, has been recognised as being of national importance and designated an Area of Outstanding Natural Beauty (AONB).

The Edge is topped by woodland and its steep scarp face looks out across low lying agricultural land. The dip slope is covered by a patchwork of fields and small villages, occasionally broken by quarries.