Flint is the dark grey to black nodular material commonly found in chalk. It is Cretaceous in age (146-65 million years old). Flint breaks with a pronounced conchoidal (curved) fracture creating sharp edges. This feature was exploited by early man to create edged tools.
It is made up of a mineral called Chalcedony, this is a silica mineral with no obvious crystals. It formed either by the deposition of silica on the sea floor from animals with silica based skeletons or by replacement of rocks by silica from percolating waters long after the mineral has been deposited.
Flint is only formed in areas south of the Tees Valley. It was brought to our beaches as ballast by ships from London coming to trade on the Tees. They would dump the ballast and carry iron and steel away from the area.
2 Comments
Flint is also found on the North York Moors, well away from the coast and industrial Teesside. Neolithic inhabitants transported flint from Cretaceous rocks, e.g. around Flamborough in order to make flint implements. The above specimen is a tool, probably for cutting flesh. There are many flint sites on the Moors, e.g. White Gill south of Esklets.
Would it be a good idea to give some idea of the size of this piece of flint?