A study of the Ajo copper ore minerals

The following thesis describes part of a set of ore specimens collected by James Gilluly and the writer at Ajo, Arizona during the early summer of 1932. This field work was done for the United States Geological Survey, and while considerable geologic work was done, only passing mention will be made concerning the geology, as the conclusions reached properly belong to Mr. Gilluly and will be published by him at some future time. Mr Eldred Wilson of the Arizona Bureau of Mines has kindly put at my disposal a number of polished sections which he collected in 1923 from the semi-oxidized zone in the southwest part of the orebody. In all, about 50 polished sections were studied in detail and the conclusions reached concerning the paragenesis of the ore minerals are based entirely upon the evidence presented by these sections, as the field relations are not in my possession