The Pb isotope database for sulfide deposits and occurrences in the Western United States was funded by the Mineral Resources Program, U.S. Geological Survey (USGS). Reports on Pb isotope data from Alaska were published in Church and others (1987a) and Gaccetta and Church (1989). The primary objectives of the project were three-fold:
* To utilize Pb isotope signatures, in conjunction with the regional mapping, to assess the relative ages and to categorize the types of deposits studied,
* To relate the Pb isotope and trace-element geochemical signatures of specific deposits and occurrences to ore-forming processes, and
* To use the Pb isotope data to correlate lithotectonic terranes within the northern Cordillera.
The report by Church and others (1987b) shows how this fingerprinting methodology can be applied to trace the offset of lithostratigraphic terranes