ABSTRACT
The St Laurent Einville mine is located in the Lorraine region in eastern France. Exploitation of salt in this mine has started at the end of the nineteenth century by the method of abandoned room and pillar with an average recovery rate of 75%. The first area, located east of the mine was operated before 1905 with slightly arched rooms 10 m wide and 4 to 4.5 m in height and square pillars 10 m aside. In the rest of the mine, mining was conducted with a different pattern defined by rooms 15 m wide and square pillars 15 m aside. The overburden has a thickness increasing from east to west in a range between 110 to 150 m. A small crown pillar of salt of 0.2 to 0.4 m thickness was abandoned in the roof to avoid discovering the laminated salt which includes marl beddings. However, at the footwall, pillars are directly based on the highly stratified marl.
