Uranium‐lead Method on Zircons*

In this paper I report some data obtained by a study of zircons from a single block of granite approximately 1.5 cu. ft. in volume. The purpose of this investigation was to better our understanding of geological, mineralogical, and physical-chemical controls on the behavior of U-Pb equilibria in these systems. Along with such parameters as zircon grain size, zoning, and morphology, my associates and I hoped to couple the study with a fair understanding of the geologic history of this particular granitic mass; this understanding is based upon a five-year field-mapping and laboratory-investigation of the area in which the mass is found.