Exploration for Zn-rich mineralization in the semi-arid Cobar region of NSW, Australia

Abstract

ABSTRACT Soils from the vicinity of the Endeavor Mine, in the Cobar region of western NSW, have been sieved into the (a) 2–4 mm, (b) 1–2 mm, (c) 0.5–1 mm, (d) 250–500 μm, (e) 125–250 μm, (f) 63–125 μm and (g) Elevated Pb and As contents in the coarse or magnetic fraction of soils in the Endeavor Mine area reflect the underlying weathered Pb–Zn mineralization and may give rise to a larger anomaly than that defined by conventional magnetic lag sampling. Within this area of Pb and As anomalism, the fine fraction of the soils directly above the Northern Pods mineralization ( c . 400 m below) exhibit enriched Zn, S and soluble salt contents (the latter measured as electrical conductivity). The association of elevated Zn, S and EC (electrical conductivity) suggests sulphide-derivation and such anomalism appears more prospective than Zn-only anomalism in fine soil fractions from transported material to the SW of the mine. Unfortunately the preparation of the fine soil fraction is time consuming but, because the fine fraction of the Cobar region soils consistently represents 40–50% of the 2 mm soil fraction for determining Pb and As and the