Salt, like honey, can be a remarkable preservative, keeping hair, flesh and bones in something close to a pristine state for thousands of years. 'Pristine', at least, compared to the rapid decomposition of corpses left exposed to air and bacteria.
From Press TV :
The sixth Iranian salt man was discovered in a salt mine in the central province of Zanjan, where five other similar discoveries was made.
It was discovered around the area of a mine where the second salt mummy belonging to the Achaemenid and Parthian dynastic eras was discovered.
Chehr-Abad is a historical salt mine of Zanjan where other salt men dating back to the Sassanid era (224 - 651 AD) were previously found.
Items found with the previous skeletons, which include leather shoes, a leather bag, a terra cotta lamp and two cow horns, which have probably been used for the transportation of oil, are mostly intact.