Assessment of Undiscovered Copper Resources Associated with the Permian Kupferschiefer, Southern Permian Basin, Europe

Abstract

This study synthesizes available information and estimates the location and quantity of undiscovered copper associated with a late Permian bituminous shale, the Kupferschiefer, of the Southern Permian Basin in Europe. The purpose of this study is to (1) delineate permissive areas (tracts) where undiscovered reduced-facies sediment-hosted stratabound copper deposits could occur within 2.5 kilometers of the surface, (2) provide a database of known reduced-facies-type sediment-hosted stratabound copper deposits and significant prospects, and (3) provide probabilistic estimates of amounts of undiscovered copper that could be present within each tract. This assessment is a contribution to a global assessment conducted by the U.S. Geological Survey (USGS).

Permissive tracts are delineated by mapping the extent of the Kupferschiefer that overlies reservoir-facies red beds of the lower Permian Rotliegend Group. More than 78 million metric tons (Mt) of copper have been produced or delineated as resources in the assessed tracts, with more than 90 percent of the known mineral endowment located in Poland. Mines in Poland are developing the deposit at depths ranging from about 500 to 1,400 meters.

Two approaches are used to estimate in-situ amounts of undiscovered copper. The three-part form of assessment was applied to the entire study area. In this approach, numbers of undiscovered deposits are estimated and combined with tonnage-grade models to probabilistically forecast the amount of undiscovered copper. For Poland, drill-hole data were available, and Gaussian geostatistical simulation techniques were used to probabilistically estimate the amount of undiscovered copper. The assessment was done in September 2010 using a three-part form of mineral resource assessment and in January 2012 using Gaussian geostatistical simulation.

Using the three-part form of assessment, a mean of 126 Mt of undiscovered copper is predicted in 4 assessed permissive tracts. Seventy-five percent of the mean amount of undiscovered copper (96 Mt) is associated with a tract in southwest Poland. For this same permissive tract in Poland, Gaussian geostatistical simulation techniques indicate a mean of 62 Mt of copper based on copper surface-density data from drill holes.

First posted January 16, 2015