Younger Dryas deposits

Vertical

Dark layer, the “black mat,” comprises carbon-rich sediments at the bottom of Younger Dryas deposits. Below: A mammoth tooth from underneath the Younger Dryas layer in Arizona is stained on top by the black mat.

YDB Working Group

Horizontal

Dark layer, the “black mat,” comprises carbon-rich sediments at the bottom of Younger Dryas deposits. Below: A mammoth tooth from underneath the Younger Dryas layer in Arizona is stained on top by the black mat.

YDB Working Group

Thumb

Dark layer, the “black mat,” comprises carbon-rich sediments at the bottom of Younger Dryas deposits. Below: A mammoth tooth from underneath the Younger Dryas layer in Arizona is stained on top by the black mat.

YDB Working Group