Clay in the soil?

Hi everybody.

Well, i've said often enough that there's no clay where i live. Tho, lately i was digging foundations for a little stick framing extension for a customer. And the ground was soo hard that i had to ask.

Here's a few pics. I think this kind of soil was either the bottom of a sea or of a glaciary lake.

Any idea if there might be some clay in this? And how do i test it?

Thanks a lot.

Max.

Max : I am not where I can check for you, the correct google search is ''Soil Settlement test '' or may be ''Soil Sediment Test'', if that doesn't work substitute the word clay for soil !

I have seen soil much like that at the old shore line of a now much smaller lake, while mine was all sharp sand and small gravel about as big as could still be used for brick laying
it was as hard as '' Rammed Earth ''! and because it was all foundation work, pick and shovel only ! Big Al

Thanks a lot Allen.

I'll do my homework.

Max,

Donkey gives a good explanation of testing for clay in his answer to this thread.

http://donkey32.proboards.com/thread/477/find-clay-perlite

Thanks to Joe Braxton for the link to an ideal and easy method to test soil for clay. I've been looking at my own soil recently hoping to find a clay layer. Past experiences with sculpting red clay and work with porcelain slips gives me a headstart on identification. But when it comes time to building my outdoor rocket-stove oven, I want the right mix. What I'm finding looks like crushed granite, kind of sandy... SHARP sand (as I noted in another thread that SHARP SAND is a must for Cob making.) We also had a couple inches of Mt.St.Helens ash deposited over all of northeast WA a few years back, so when the soil is dry, I believe that's the dust I see flying around.
Last week, I put several big shovels full of that granite/sand/ash/clay-looking layer in a wheelbarrow, added water to several inches over the top of the dirt. Shoveled it around to stir and let it sit. Two days later, when I poured off the clear water, I could see the silty clay-like layer on top. I'm hopeful about this being an ideal mix to which I only need add some cut straw bits. The area I'm digging out is my new Hugelkultur bed. I'd already pulled all the rich topsoil off the top. Just need to sweep the rest of the organic matter off that Hugel bed and begin scooping out some of my future granite/sand/clay cob mix.

So I followed one of the links in the proboard thread and pulled up the USGS soil report for my place. Sand. 100% sand, and just one variety. Chuckle. I would have bet money on it, and now the USGS tells me it's true. I think I'll do some of the tests Donkey described anyway, in hopes that maybe there's a bit of clay hiding in there someplace