B. R. Doe J. D. Wells R. O. Rye 1974 <p>Isotope studies of sulfur, carbon, hydrogen, oxygen, and&nbsp;lead were carried out to clarify the age and origin of the Cortex gold&nbsp;deposit and the surrounding mineralized area. The hydrogen isotope&nbsp;data indicate that meteoric water was the dominant component of the&nbsp;ore-forming fluids at Cortez. The hydrogen isotope data support&nbsp;geologic evidence for a Tertiary age for the deposit. The oxidation of&nbsp;the ore probably occurred during the deposition of postore calcite and&nbsp;was caused by waters whose oxygen isotopic composition was distinctly&nbsp;different from that of the ore fluids. The carbon isotope data suggest&nbsp;that the only carbon present in the ore fluids was derived from solution&nbsp;of the host rock. The lead and sulfur data are consistent with a possible&nbsp;sedimentary derivation for the gold in the ore. Lead and sulfur isotope&nbsp;distributions indicate that much of the galena mineralization in the area&nbsp;occurred during the Jurassic.</p> application/pdf en U.S. Geological Survey Stable isotope and lead isotope study of the Cortez, Nevada, gold deposit and surrounding area article