erosion

In fact, the turtlebacks are complex three-dimensional entities that formed over ~ 14 m.y.
of extensional overprinting on an older Mesozoic framework. We submit that many of the controversies regarding the Death Valley region in general, and the turtleback systems in particular, stem largely from the inability to communicate observations of these multiple dimensions. Even the coauthors of this paper are not in complete agreement on several details, but our approach here is to clarify our view of the four-dimensional history.