Remember the story of Lot's wife ~ it's an ancient tale also told in pictoglyphs in Northern Finland and nearby Russia.
It may be 7500 years old ~ which is 3 times as old as this item.
The Bible doesn't really explain why Lot's wife turned to (rock) salt, but the petroglyphs explain it clearly as a consequence of her failing to find husbands for her daughters.
Eventually we are going to be able to pin down the sources for the stories Moses thought suitible for inclusion in the Bible he put together.
http://www.biblegateway.com/passage/?book_id=1&chapter=19&version=31
Genesis 19
16 When he hesitated, the men grasped his hand and the hands of his wife and of his two daughters and led them safely out of the city, for the LORD was merciful to them. 17 As soon as they had brought them out, one of them said, “Flee for your lives! Don’t look back, and don’t stop anywhere in the plain! Flee to the mountains or you will be swept away!”
26 But Lot’s wife looked back, and she became a pillar of salt.
She wasn’t turned to a pillar of salt for failing to find husbands for her daughters. The daughters were betrothed but the husbands stayed in Sodom and Gomorrah.
She “looked back” and became a pillar of salt. This may mean she longed to return to the doomed cities. That’s how I’ve heard it explained.
Can't be since the worldwide flood of Noah's time was only 4760 years ago, nothing survived but one big ark and it's passengers. Therefore making the Biblical account the oldest and most reliable account. Lot's wife turned back to look, in doing so she disobeyed God, who in turn punished her. A lesson we today would do well to learn.
The Bible relates that they were told not to look back, no matter what, and she did. That was her punishment. She’s been a salt lick ever since.