The Giant Pebble Cu-Au-Mo Deposit and Surrounding Region, Southwest Alaska: Introduction

Autor: Robert G. Eppinger, Karen D. Kelley, James R. Lang
Rok vydání: 2013
Předmět:
Zdroj: Economic Geology. 108:397-404
ISSN: 1554-0774
0361-0128
Popis: The Pebble deposit is located about 320 km southwest of and 27 km northwest of the village of Iliamna in Alaska (Fig. 1A). It is one of the largest porphyry deposits in terms of contained Cu (Fig. 2A) and it has the largest Au endowment of any porphyry deposit in the world (Fig. 2B). The deposit comprises the Pebble West and Pebble East zones that represent two coeval hydrothermal centers within a single system (Lang et al., 2013). Together the measured and indicated resources total 5,942 million metric tons (Mt) at 0.42% Cu, 0.35 g/t Au, and 250 ppm Mo with an inferred resource of 4,835 Mt at 0.24% Cu, 0.26 g/t Au, and 215 ppm Mo. In addition, the deposit contains significant concentrations of Ag, Pd, and Re (Northern Dynasty Minerals, 2011). Fig. 1 A. Map of southwestern Alaska showing extensive cover by Tertiary and Quaternary deposits and locations of known mineral deposits with outline of the Pebble district. Distribution of Tertiary and Quaternary deposits is after Wilson et al. (2006). B. Map of the Pebble district showing locations of deposits (all deposits are named as zones, for example the 37 zone). Regional mineral deposit locations are from U.S. Geological Survey (2008); descriptions of district deposits are in Hawley (2004) and Lang et al. (2013). Boundaries for the Pebble West and Pebble East zones are based on >0.3% and >0.6% Cu equiv, respectively. Fig. 2 The 25 largest porphyry copper deposits, based on (A) the tonnage of contained copper metal and (B) the tonnage of contained gold (modified from Cooke et al., 2005). The classifications of deposits into Cu ± Mo, Cu-Au-Mo, and Cu-Au types are described in Cooke et al. (2005). Unlike most porphyry deposits in southwest Alaska, which are
Databáze: OpenAIRE
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