Monday, April 24, 2023

Olympia Nonglacial sediments south of Penn Cove

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. 

It appears that a thin sandy layer had a bit more water flow leaving a darker banding of iron staining. 

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.
Thick layer of glacial till forming bluff cliffs just to the southeast of the Olympia non glacial sediment exposures and off sets. 


Sunday, April 16, 2023

Observing landscapes I have not been to

I had a long day of travel with a walk to the train station, the long train ride and then the long plane ride. I had a window seat on the flight. I did get a glimpse of northernmost Scotland and the north coast of Iceland. Then flew over landscapes I have never been to and that are not easy to get to.  

Ice cap area of Greenland

Islands and a frozen sound on the west coast of Greenland

Tracks across snow covered ice to and from Uummannaq, Greenland

Large landslide?

I have read tales of arctic ventures across the ice. Good ice on the left and not so good on the right

Glacial striated land with frozen lakes and forest
This time of year might be the best time to travel through this landscape

Gas and oil wells in northern Alberta

Cold Lake Canadian Air Base and the Beaver River

Vegreville, Alberta and snow melt pattern along roads
The Canadian Rockies

Dropping down out of the clouds over Seattle