Here's a breakdown of what that means:

* Volcanic: It originated from a volcanic eruption.

* Breccia: This type of rock is made up of angular fragments of other rocks that have been cemented together.

In the case of Shiprock, the angular fragments are pieces of volcanic rock, mostly volcanic ash and pumice, which were ejected from a volcanic vent millions of years ago. These fragments cooled and solidified, forming the distinctive, spire-like shape of Shiprock.