Monday, December 30, 2013

Winter Beaches

Banded Jasper or...?
The beach below my house is primarily sand, esp. during the quiet months of summer, when the surf is at a minimum. But in winter, storming winds and tides throw rocks up onto the beaches, and right now there is a thick layer of pebbles at the tideline. This is perfect for sampling the extraordinary diversity of rocks that characterizes this ancient glacial landscape.

This good-sized cobble attracted my attention today. It was heavy and glass-smooth,  typically a sign of a hard rock like agate or jasper, but with some lovely green and brown banding.  I haven't seen anything like it here before - but that is almost always the case here : rocks deposited on my beach are likely remnants of boulders dropped by glaciers here 10, 000 years ago.

In any case, I popped it into the tumbler - and in a week or so, I'll be able to get a clear look at it. Then it will either go into polishing - or get tossed back onto the beach.

Alki Beach,  New Year's Eve Eve, 2013