By Capt. Paul (Eclogite) on Tuesday, May 22, 2007 - 08:23 pm:
The only dumb question is the one not asked!! :-)
In the most strictest sense, a sand dune is wind deposited sediment. A moraine is sediment (till)deposited directly from melting ice. There are many different types of moraines out there, which can have different characteristics. As I said earlier, McLain sits on top of a glacial moraine, but I didnt say it was composed of one. Lake level fluctuations, sand weathered from the Freda Sandstone, and changing climate at the end of the last ice age all played a role in the sand being deposited at McLain. And with time, the sand does move around; I have photos in our gallery from Grand Sable Dunes of the "ghost forest" where the shifting sands had killed an entire forest about 4,000 years ago.
By Danbury (Danbury) on Wednesday, May 23, 2007 - 03:50 am:
Thanks, Captain. I'd rather you did not leave it at that :) because the rest whas what I wanted to know.
By Toivo from Toivola (Toivo) on Wednesday, May 23, 2007 - 05:08 am:
Them are some pretty old photos, Capt. -- I know the Gallery has been on hold for quite a while, but I didn't know they even had cameras 4,000 years ago.