Geologists Discover New Layer in Earth���s Mantle

"Earth���s main layers are the thin crust 4 ��� 50 miles (6.4 ��� 80.5 km) deep, a mantle extending 1,800 miles (2,900 km) deep and the iron core.
But there are subdivisions."

Source: http://www.sci-news.com/geology/science-new-layer-earths-mantle-02631.html

Fascinating stuff!
Maddy