#greenschist

Mineral under pressure

This is a photograph of mineral called pyroxene and was taken with a petrographic microscope, and it captures megascale forces of the tectonic processes on the microscale level. This mineral is about 1.5 mm and was found in a rock called greenschist.

This rock is heavily deformed, sheared, due to the force of the tectonic plates pushing against each other. Imagine one plate being a bread and other a knife, and the rock you are looking at is like a butter being smeared on the toast.

The pyroxene is harder than the rest of the minerals in this rock, and so, as the pressure is applied, the other minerals are deformed and squashed against the pyroxene while it remains largely undamaged.

Example from the Nubra Valley, Ladakh, Himalaya