Mining Salt in France
November 16, 2017
Photographer: Ottone Scammacca
Summary Author: Ottone Scammacca
The photo above was taken in the only underground mine in metropolitan France; a salt mine located near Varangeville. The huge deposits here were discovered in 1819. The layers of rock salt (halite), composed essentially of sodium chloride (NaCl), are relatively superficial (about 525 ft or 160 m from the surface), having formed from the evaporation of old deposits of potassium around 250,000 years ago. These underground salt mines spread out below the surfaces of three communities, yet mining activity appears to have had little impact on the infrastructure of any of them. After a partial collapse in 1873, the structure of the mines now consists of large cells divided by sizeable pillars, their stability, and thus the miners' safety, has not since been compromised by wanton exploitation. This working environment doesn't seem that different from that of most major industrial plants. Photo taken on October 16, 2017.
Photo Details: Camera Model: Canon EOS 1300D; Lens: EF-S18-55mm f/3.5-5.6 III; Focal Length: 55mm; Aperture: ƒ/5.6; Exposure Time: 0.017 s (1/60); ISO equiv: 3200.