Dan Arcadi

Identification of Bismuth and Tellurium Bearing Minerals within a Carlin-Type Gold Deposit: Nevada

(Dr. Brian Snee, Advisor)

arcadiMost of the gold mined in Nevada as well as the entire United States comes from a specific type of deposit known as a Carlin-type deposit.  Carlin-type gold deposits contain a small concentration of gold dispersed throughout a large volume of host rock.  In addition to gold, Carlin-type deposits also contain high yet uneconomical concentrations of other elements, including antimony, arsenic, barium, mercury, silver, and thallium.  This suite of elements is characteristic of only Carlin-type gold deposits and acts as a valuable exploration tool in searching for this type of gold deposit. In addition to the typical suite of elements associated with Carlin-type gold deposits, workers at the Cortez (Carlin-type) gold mine in north-central Nevada have also noted elevated concentrations of bismuth and tellurium within gold ore.  The relationship between the gold and the bismuth and tellurium is unknown, as are the mineral species that contain the bismuth and tellurium. The occurrence of bismuth and tellurium has not been documented in other Carlin-type deposits and the presence of these two elements within gold ore from Cortez may indicate a geochemical “signature” unique to the Cortez gold deposit. Through analysis of gold ore samples from the Cortez mine I hope to identify the minerals that contain the bismuth and tellurium.  With this information I can determine the association, if any, of the minerals to the gold in the Cortez deposit.