Cornstone is a limestone containing a large quantity of arenaceous matter or sand.
"Geology"
James Geikie
But there are other reasons for the comparative paucity of fossils in arenaceous strata, as we shall see presently.
"Geology"
James Geikie
The arenaceous or argillaceous stuff in which they lie embedded is extremely hard, and strongly impregnated with iron, usually in the form of iron pyrites, which binds it together.
"Impressions of South Africa"
James Bryce