I had a venture on the east coast of Whidbey Island a bit south of Penn Cove. The geology strata changes rather substantially along the shore. The last time I had been to this shore reach the tide was not favorable but this time I could take in some of the nuances of the bluff geology.
The carbon-rich layer at the base of the bluff provides an age of about 35,000 years (Polenz, Slaughter and Thorse, 2005). These are non glacial sediments deposited during the period prior to the last incursion of glacial ice out of British Columbia into the Puget lowlands. These non glacial units have been termed Olympia deposits.
The fine silt/clay layering is horizontal but there is an overprint of oxidized iron staining that confuses the eye as the staining is a bit convoluted.
I first observed this offset a few years ago and had forgotten about it. I found several other offsets nearby.
There are a number of fault zones that trend across the Puget lowlands from the southeast to the northwest. These off sets may be associated with those fault zones, but they also could be glaciotectonic. That is the thick glacial ice sliding over the area and loading the land surface with a few thousand feet of ice could be the source of deformation of these pre glacial sediments.