The Danian limestone is near the surface along the sides of the trough. The southern flank is the longest, and it is at the eastern end of the fault here that Hjerm limestone quarry is located. The limestone has been dated to Late Danian, macrofossil zone D, chalk nannofossil zone 8. The chalk, flint and fossils are dealt with in more detail under sites G24 - Odby Klint and G49 - Bjørndal limestone quarry.
Chalk has been mined for agricultural purposes since 1770, but excavation and firing in kilns did not start seriously until the late 1800s. A large circular kiln was built in 1893, and mining took place underground so that the industry was also active in the winter months. Firing of limestone in kilns ceased in 1941, and the excavation of limestone for agricultural purposes ceased in 1957.