Perhaps the most impressive story about flint is that of the ancient mining complexes that were built in what is now England during Neolithic times. These excavations began about 4000 BC and continued until the widespread use of metals about 2,000 years later.

One flint mining complex of particular note was Grime’s Graves located near Brandon, England. Here ancient miners dug shafts down through 40 feet of Cretaceous chalk to a layer of high-quality flint below. Each shaft was several feet in diameter and required the removal of about 2,000 tonnes of chalk. Most of the digging was done without metal tools, using red deer antlers as picks. Each shaft required a team of workers and took several months to construct.

About 60 tons of flint could be removed from each of these pits and the short horizontal excavations that followed the high-quality flint layer at the base. Starting about 3000 BC until about 1900 BC, these miners built over 400 shafts over an area of about 100 acres and removed thousands of tons of flint.

Although these mining operations were amazing feats of engineering, just as impressive was the geological understanding of the workers. They knew that the flint was below the ground even though it did not outcrop anywhere in the immediate area. They also knew that the highest quality flint layer was below lower quality zones that were encountered during the early digging.