Saturday, July 20, 2013

Ledgewood






I was lucky to visit Ledgewood the afternoon of the big landslide back on March 27th, and then again briefly one week later.  But I hadn't been able to get back until very late on the afternoon of July 10th (this blog is relatively sequential, but rarely live).

Ledgewood:  27 March 2013

My visit was brief, as the tide was rising and I didn't want to get squeezed too tightly between the water and the drift logs hanging over the edge of the old beach - 15' above my head.

The toe of the slide has eroded rapidly this spring and much of the uplifted beach has now been redistributed by waves to the adjacent beaches (see Ian's blog below). Most of the eroding scarp consists of a thick sandy unit.  In the top foot or two there are some gravel layers that are consistent with the upper surface being a raised beach.  The toe of the scarp consists of the deformed dark gray clay that I assume marks the slide surface.  I can't wait to see a more through geologic analysis of this thing -- the thick sand is intriguing and I'd like to hear if folks understand the origin of the clay or its role in the slide.




The scarp has not yet reached the displaced pre-March drift log line.  Maybe some time next fall, the retreating bluff will reach the back of the uplifted beach and begin to work its way into the forest. As this promontory gradually succumbs to waves over the years to come it will probably leave a beach underlain by hummocky clay and covered with fallen trees.

Ian Miller with Sea Grant has been following the slide and has posted observations and time-lapse video on his blog:
http://coastnerd.blogspot.com/2013/07/coastal-sediment-distribution-from.html

If anyone is aware of more geologic information available online, feel free to mention it in a comment.

Google Maps:  AERIAL VIEW



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