Our two deep wells (casings about 5", IIRC), which go down roughly 100' and 150', each produced enough material to seal a large kiddy pool, if it had all been suitable clay.
I was afraid of that. Thanks, Theo.
"Only after sorrow's hand has bowed your head will life become truly real to you; then you will acquire the noble spirituality which intensifies the reality of life. I go to an all-powerful God. Beyond that I have no knowledge--no fear--only faith."