title: On the Presence of Fixed Ammonium in Rocks.
abstract: From one-fourth to one-half of the nitrogen in some granite rocks, and up to two-thirds of that in some paleozoic shales, occurred as ammonium ions held within the lattice structure of silicate minerals. The results provide greater insight into the origin of the earth's atmosphere.
authors.forename: F J
authors.initials: FJ
authors.lastname: Stevenson