On Tue, 11 Nov 2003 13:34:59 -0000, "Finance"
wrote:

Clay is good soil packed badly. I have heavy clay over yellow clay over blue
clay. After 20 years the heavy clay has been improved. The yellow clay has
not changed and I doubt if I will long enough to improve the blue clay.
Incidentally blue clay was used to puddle the bottom of ponds, so you have
an idea of it's use

Everything you wanted to know about the microstructure of clays and
were frightened to ask
http://www.tam.uiuc.edu/courses/TAM2...y_minerals.pdf
--
Martin