Geology and Minerals

The documents listed below are Baseline Reports categorized topically as geology and minerals.

The purpose of this tech memo is to describe and present the results of a ADEQ Tier 1 geochemical characterization program of development rock for proposed Shaft No. 10 based detailed sampling and analysis of samples from a pilot drill hole along the entire vertical section of the proposed shaft.

At the request of Resolution Mining Company (RMC), this report presents the results of sitespecific probabilistic seismic hazard analyses (PSHA) and deterministic seismic hazard analyses (DSHA) of four sites for the RMC tailings storage facilities options in southern Arizona.

In 1995, the Magma Copper Company discovered a porphyry copper deposit beneath thick postmineral cover 2 km south of the historic Magma mine in Superior, Arizona. Since that time drilling has delineated a large, high-grade, hypogene copper-molybdenum deposit, now named the Resolution deposit, with an inferred resource of 1,624 million metric tons (Mt) at 1.47% Cu and 0.037% Mo.

An investigation of hydrogeologic conditions for the Superior Basin has been completed by Montgomery. The chief objective of the survey was to evaluate the cause of recent water level declines reported for some wells located within and adjacent to the Queen Creek corridor through the Superior Basin, as well as observed declines in discharge from Whitlow Ranch Dam.

This tech memo has been prepared to summarize results of the Phase II field investigations of the Near West site, conducted in support of RCM's ongoing prefeasibility studies for storage of RCM mine tailings. The purpose of Phase II investigations was to conduct electrical resistivity surveys to assess the potential occurrence of shallow groundwater at the Near West site.

This tech memo has been prepared to summarize results of the Phase I hydrogeologic assessment of the Near West site, conducted by Montgomery & Associates in support of RCM's ongoing prefeasibility studies for storage of RCM mine tailings. The purpose of the Phase I assessment was to conduct non-invasive field investigations to supplement information obtained previously from published data and to plan Phase III investigations involving subsurface exploration drilling and hydrologic testing.

Earth Systems was engaged to conduct kinetic geochemical testwork on tailings samples generated from pilot scale metallurgical testwork for the Resolution Copper Mine.

A probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA) were performed for Resolution Copper’s Mine site including the area above the deposit (Mine area) and the area covering the East Plant site (Shafts 9/10). The peak horizontal ground acceleration (PGA) value for a return period of 2475 years is 0.06 g. This return period is used in the International Building Code (IBC) for the design of typical buildings and other structures in the U.S.

Snapshots Updated

The Forest Service is considering five reasonable action alternatives for a Tailings Storage Facility. To view Snapshot summaries and accompanying maps, click here.

View Updated Snapshots

EIS Status

Thumbnail image of EIS Status file

EIS Status graphic updated March 2018

Forest Points of Contact

Media & General Info
John Scaggs
jscaggs@fs.fed.us

Project Manager
Resolution Copper
Mary Rasmussen
mcrasmussen@fs.fed.us

Apache Leap Special Management Area
Apache Leap SMA website