Welcome to the Yeovilian!

Geologists often name rock formations, and the deep time intervals in which they were formed, from the regions where they were first studied.

The Jurassic, 201 to 145 million years ago, is named after the Jura mountains along the border between France and Switzerland. The Devonian, 419 to 359 million years ago, after the ancient red sandstones of Devon.

But did you know that our region has its very own geological time interval?

The Yeovilian, 180 to 175 million years ago, lies within the Early Jurassic. It was first defined by the palaeontologist and stratigrapher Sidney Savory Buckman (1860-1929) from his meticulous studies of fossil ammonites. He lived nearby in Bradford Abbas.

The relatively soft ochre sandstones of our region, the Yeovil Sands (also known as the Bridport Sand Formation) were laid down in the shallow, turbulent, tropical seas of the Yeovilian. They now form our characteristic landscape of steep sided hills and valleys, disected by holloways (sunken lanes).

Also, the impressive plateau of Ham Hill with its protective cap of limestone (Hamstone). Hamstone quarries have provided the distinctive, warm honey-coloured building stone of our towns and villages for millennia.

You can explore the geology of Ham Hill with our self-guided walk:

Ham Hill Geology Trail

Celebrating Earth Science Week October 12–18, 2025

Image credits:

Sidney Savory Buckman (1860-1929) © Wikimedia Commons 2021

Plesiosaur and Ammonite in Early Jurassic seas  © Aria Baskakova 2019

Ham Hill Deep Quarry © British Geological Survey UKRI