This image shows the Bandelier Formation in Pueblo Canyon east of Los Alamos, New Mexico, USA. The lowermost dark beds are 2.5 million year old basalt of the Cerros del Rio. Above this is a thick bed of Guaje Pumice, an air fall pumice erupted at the start of the Toledo event 1.62 million years ago. This is overlain by Otowi Member ignimbrite from later in the same eruption. Above is a poorly exposed bed of Pueblo Canyon Member, Toledo Formation, and then ignimbrite of the Tsherige Member of the Bandelier Formation, which was erupted 1.25 million years ago.
<a href="//commons.wikimedia.org/wiki/User:Kent_G._Budge" title="User:Kent G. Budge">Kent G. Budge</a>
<span class="int-own-work" lang="en">Own work</span>