a.k.a. Stratigraphic way up, or younging direction

This post is part of the How To… series

Stratigraphy is all about succession in the rock record – which events preceded other events; which is older, which younger. Nicolas Steno (1638-1686) surmised, and four centuries of geologists since have confirmed that in an uninterrupted succession of strata, the youngest layer is at the top.  However, tectonic hiccups and upheavals have frequently turned successions of strata sideways or on their head. In this case, knowing which way is ‘up’ will confirm which strata were overturned. Continue reading →