Green and red marl, shale, and shaly limestone with some veins of gypsum.
Beds of gypsum have been discovered on the head waters of the Pere Marquette.
To every hundred pounds of this powder, about three pounds of gypsum is added.
The United States is the largest producer of gypsum in the world.
Production of gypsum in the United States comes from eighteen states.
In some of these domes are also found petroleum, gypsum, and sulphur (p. 110).
They remembered the gypsum hills over which they had ridden on the preceding day.
"There is an extensive underlying layer of gypsum, here," he said.
The polish is not lasting, however, because the skin of gypsum is very thin.
At Gypsum creek our latitude was 36 10being the utmost northing we had made.