Sunday, August 16, 2015

Notes of Innis Creek Road and a View of the Twin Sisters Dunite

Innis Creek Road is a patched up bit of road that frequently is flooded by water backing up in the swampy ground the road crosses. With the dry warm weather, the road was not covered with water.

This stretch of road crosses a short-lived former path of the late ice age melt water channel that cut through the terrace between what is now the South Fork Nooksack River valley and the upper Samish River valley.

On clear days this area of the Samish/South Fork Nooksack provides a great view of the Twin Sisters Range.  
The Twin Sisters consists of a fault bound block of dunite. The dunite is mostly olivine that has weathered to a distinctive orange color. The ridge reaches about 7,000 feet. The combination of very heavy winter snow and poor growing conditions for plants on olivine rocks gives this mini range in the Northwest Cascades a distinctive look.    

1 comment:

Anonymous said...

Hi Dan

Thanks for the great Lidar image. The area where the Samish and the SF Nooksack headwaters are has always been mysterious to me as I drive along SR9.

Barb Hathaway