Resolution Copper Mining Company (RCM), acting jointly with Rio Tinto (RT-OTX), asked Mark Logsdon (Geochimica, Inc, Aptos, CA) to prepare a plan to geochemically characterize the rock mass that may be subject to chemical weathering as a consequence of block-caving operations at The Resolution property near Superior, Arizona. Results from this study will be used by RCM and its contractors to develop a geochemical model of the block-cave zone as it affects operational and closure considerations.