New York City's saltshed

Friends of the Pleistocene tells a fascinating detective story about where New York City's road salt comes from--not from vast salt mines in upstate New York, but from much farther away.

This week New York City will become, as most cities will at some point this winter, coated with a temporary geologic layer. It isn’t a “new” layer, but an ancient one. Its presence results in an odd rearrangement of geologic time.  New York City, a combination of Anthropocene and Pleistocene shaped surfaces (dating from the present to 2.5 million years ago), is being encased this week by a thin stratum made, literally, of the stuff of 8-10 million years ago.