On 7th June 2022 28 walkers from Loftus Walkers are Welcome set off from Loftus Town Hall on their annual Geology walk which this year was into the moonscape-like terrain of the former Hummersea Alum Quarries along the East Cleveland Coastline.

From this land, Alum was quarried, processed, and exported from 1640 until its closure in 1870. Aniline, a derivative from coal tar distillation was found to be most effective as a carrier for dyes in textile manufacture. It was from these cliffs at Hummersea and Boulby that a young Scientist, Lewis Hunton, son of the Alum Manager, William Hunton, made an important discovery that developed from the skills of the Alum workers and their knowledge that fossils could be used to inform on the strata most suitable for making Alum.

Through meticulous study and recording, Hunton helped to lay the foundation for major biostratigraphic advances through his insistence that only fossils collected in situ should be used in such work. He then went on to propose that the species of ammonites in this Yorkshire strata, had particularly limited and invariable relative positions within the lithological sequence. From these quarries were extracted a fossilised Ichthyosaur which fed on ammonites also a Plesiosaur. This and neighbouring quarries also provided the raw materials to produce Epsom salts and Roman cement (now called Hydraulic cement).

During our visit, walkers found many fossilised ammonites within the shales. The fossil record from strata over 130 million years is contributing to our understanding of climate change. The group had a number of rests during the steep climb up to the Cleveland Way but the view out to sea often reveals Dolphins as they navigate along the coastline.

The Lewis Hunton self-guided trail and other fascinating walks around Loftus can be downloaded from their website. 

Marshall Best