>>119405East Texas clay. I've exposed the layer of clay in the hole and cleared away the sand and silt so that by the time I come back from my wisdom tooth surgery, it should sun-dry into a flat, concretelike surface for my floor. Also with the colored impurities, the material would probably also make for really beautiful pottery.
Next steps in construction will be building up mounds on the perimeter of the hole and laying the beams for the roof.
