The proposed Berryessa-Snow Mountain National Monument region provides unparalleled access to geologic features associated with an ancient tectonic system where one plate descended beneath another.

Jupiter's icy moon Europa is criss-crossed by extensional features. A tectonic reconstruction suggests that Europa's extension is balanced by subduction — if so, Earth may not be the only planetary ...

The 100 sites receive recognition because they are deemed to be of high scientific value and the world’s greatest demonstrations of geologic features and processes. Recognition on the list can lead to ...