Field of Science

A geologist riddle #7

An "impossible" outcrop - the rocks where already recognized in 1867, but only a discovery in 1970 revealed an incredible environmental change - what is the significance of this site?


  1. Is that the Gubbio layer in Italy? (What I learned to call the K/T boundary, now K/P or something) It doesn't quite look right...

  2. I'd have to guess K/T boundary, but wouldn't venture where. Looks a lot like rocks on the Colorado Plateau, in general.

  3. It´s in Italy, and even it is a chronostratigraphic boundary, but much later than C/P - I added a photo with an important detail and would say that there is a connection to modern Death Valley...

  4. The important detail seems to be something like evaporite, isn't it ?
    So maybe the "incredible environmental change" discovered in 1970 (with Leg 13 of the DSDP)is the Messinian salinity crisis, at the end of Miocene.

  5. The environemntal change is the complete evaporation of the Mediterranean Sea due to the closure of the strait of Gibraltar. How you rock guys figured out it was a few million yerars ago is beyond me.


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