[Cob] topsoil

[Janet Standeford]

How far down should you go to get beneath topsoil in a vegetation rich
environment? I went down 6-8 inches and found soil in a tiny valley that
had some miniature root stragglers and since it was already wet I
squeezed some together and  found it to be nearly pure clay. It is
sticky so I had to scrape it off the shovel and when pressed, it held
together  until it was down to about 1/8 of an inch then it started to
fall apart..

Thought I'd run this by you guys before I use it for my samples as I
have limited time to get these tested so can't spend a lot of time
playing with it.

By the way, does clay not freeze? The first 4-6 inches of dirt was
frozen then it became very easy to shovel out.

Hoping to make some initial sample blocks this weekend but need to know
where to find a small amount of hydrated lime and a small amount of
portland cement.

Any ideas? I am really grateful to have the support of such a great
group of people. Some of the individual emails make me feel like
extended family. Thank you.