Day Two of my stratigraphy trip: Tygh Valley- White River Gorge section

Day two of our trip found us doing much of the same thing as yesterday: mapping fluvial and volcanoclastic deposits. This time we learned how to measure strike and dip of the observed bedding. Here’s an aerial view of our work area:


This out crop is where we spent most of our time taking measurements. What you’re seeing is some severely tilted beds of volcanoclastic material. The dip is nearly 60 degrees at the top and becomes less angled as the bed continues dipping.


A slightly closer shot of the same area:


Here’s a close-up of the clasts present in some of the bedding:


The source of the tilting is probably some plutonic intrusion. I’m inferring this based on the presence of a sill that sits just to the left of the first set of tilted bedding.

Here’s the view at the top of the basaltic rimmed plateau. Not sure if my camera got it, but you can see Mt. Hood in the background.