Wednesday, January 23, 2013

Tube Worms in Bellingham Drift

I had a couple of drilling projects recently. I utilized a geoprobe. Basically a a hollow cylinder of hardened steel driven into the ground to extract soil samples.

Casey runs the geoprobe or push probe

Sumas ouwash sand and gravel on left and Bellingham Glacial Marine Drift on the right.

The sampling at one site was through a late stage glacial outwash unit called the Sumas outwash. These outwash deposits were from glacial meltwater flowing from glacial ice when the glacial ice margin was located in the vicinity of the US-Canadian border near Sumas, Washington. The ice was still present after glacial rebound had uplifted the local Bellingham area above sea level.

Prior to the Sumas outwash, the location where I was drilling was below sea level as the 6,000 feet of ice had pushed the local surface of the land well below sea level. For a time the area was below sea level with floating glacial ice on the sea surface or at least ice bergs. As the ice melted, silt and clay consisting of very finely ground rock rained out of the ice on to the sea floor.

In the picture above, the sampler captured the transition from glacial marine drift that was likely tidal to sand and gravel river outwash. There was a nice surprise in one of the clay samples.

Tube worms remains

I have encountered a few shells within the Bellingham Drift in test pits and at shoreline bluff exposures, but this was only the second time I encountered animal remains while drilling. A nice bonus on top of the good news we found doing our explorations.

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