The spoil heaps produced by the jet miners are clearly visible along the sides of Bilsdale and Raisdale. They are at about the 900 ft level in the Lower Jurassic shales which were laid down about 180m years ago when the area was located closer to the equator. The dominant species of tree was the Araucaria (Monkey puzzle tree). These were washed down the rivers into the Liassic Sea, gradually became waterlogged sank into the mud and, over time, became the small seams of jet within the shale. Bilsdale was well known for the quality of its jet deposits, particularly around Hasty bank and Garfitts. Jet mining started in the 1850s after the death of the Duke of Wellington but the jewellery became much more popular after Queen Victoria wore it as a sign of mourning for Prince Albert. In 1861 11 jet miners were recorded in Bilsdale. By 1871 there were 42 miners living in the dale but 10 years later there were only four. Many came from outside the dale and it is reported that more than 100 worked at Hasty Bank and Garfitt. It is probably that the extensive jet mining on Hasty Bank was partly responsible for the great landslip which swept the road away in 1872.
Published: 28 February 2022