Tuesday, January 14, 2014

Geology Trip Reference - Sterling Hill and Burlington Hill

I was out in the not so wild field and had a nice view up the Skagit Valley a bit enhanced but fog and clouds. I noted the fine lumps rising from the middle of the lower valley and would suggest if you want to know more about these lumps of rock check out Dave Tucker's field trip write up geology-field-trip-to-metamorphosed-marine-lava-and-sediment-at-burlington-hill-skagit-valley-washington/. The write up is also a good primer on the complex metamorphic assemblage that still perplexes.   

These two hills, Sterling on the left and Burlington on the right, along with the some of the mountain slopes have essentially no lower gentle slopes. The hills were former islands rising above a fjord like inlet that extended part way up the Skagit Valley. Glacial outwash from the continental ice margin that was hung up for a time to the north and the Skagit River with some contribution from the Samish River and some help from mud flows off of Glacier Peak has filled the fjord in and beyond creating a broad plain of rich flat farm land known locally as the Skagit Flats and Samish Flats.

The fields are a bit wet this time of year and deep ditches are excavated to speed drainage so that planting can start after the rain eases up and the temperature warms.  

1 comment:

Peter Roberts said...

That was really fascinating (the link too!). It's really cool to think about how an different our landscape used to be.