Driving back from the GSW fall field trip this past weekend, I took this photo out of my car window. Considering the vehicle was in motion, I'm pleased with the decent quality of the photo:


This house clearly shows graded bedding! There are many ways to get graded bedding showing a fining-upwards sequence of deposition, but my favorite is deposition by turbidity currents, dense sediment-water flows that drop the heaviest stuff (usually the biggest particles) first. Then as the water calms, progressively finer and finer particles settle out of the turbid water.

I was predisposed to look for graded bedding in buildings, because one of my students/ colleagues/ friends, Dr. John Weidner, took this photo earlier in the year and shared it with me:

This would be a case of inverted graded bedding, a coarsening-upwards sequence. Did this house prograde out into a basin like a delta? Or was it deposited by a turbidity current and then later tectonically overturned?

Labels: humor, primary structures, sediment