Brimham Rocks

The rocks of Brimham tell a vibrant story rooted in deep time. They stand like sentinels looking over the Nidderdale landscape but they are far from mute. They tell the story of continents colliding, of huge mountain ranges rising and falling and of immense rivers flowing over a landscape riven by earthquakes.

The time scales that cover the story of Brimham Rocks are immense and almost impossible to comprehend, even for geologists, who have split deep time into 22 periods, from the formation of the Earth 4.54 billion years ago to the present day.

Brimham’s story starts in the Cambrian Period, about 500 million years ago, with tectonic plate movements but key is the Carboniferous Period, 359 to 299 million years ago, when the rivers and deltas that were transporting vast amounts of material eroded from the mountains and depositing the sediments that formed the rocks were most active.

It was during this period 320 million years ago that an earthquake reshaped the river valley to create a braided river syste, a crucial event in Brimham’s history. The subsequent development of the Pennines during the next 250 million years and the effects of the Ice Ages from 2.6 million years ago have sculpted the rocks into the forms we see today.

The development of the science of geology has provided a framework for explaining the ages of the rocks at Brimham, the nature of the forces that created them and, in particular, how the remarkable features have been formed. In the 1830’s the Millstone Grit of the Pennines, and that of Brimham, was understood to have been formed by deposits of sediment carried by ancient rivers to the edge of shallow seas.

This concept of rivers carrying vast amounts of sediments worn away from a mountain range the size of the Himalaya, and the sediments being deposited in layers to form sandstone is now well established. More recent research has shown the vital role of earthquakes, fault zones and a dynamic braided river system in the formation of the complex rock strata in parts of the site. Other research has revealed the physics behind the erosion of sandstone that helps explain the remarkable shapes produced by the weathering effects of ice, wind and rain seen today.