Zn Pb Fe

Abstract

Cover. Polymictic sedimentary conglomerate overlying rhythmically laminated high-grade sphalerite and galena ore from the I 3/4 horizon in McArthur River (HYC) deposit, Australia. Inset shows scanning micro x-ray fluorescence (XRF) map of zinc (Zn), lead (Pb), and iron (Fe) concentrations. Deformation and partial truncation of fine, chemically graded laminae at contact with conglomeratic base of the overlying turbidite and intralaminar deformation together indicate deposition and modification through sea-floor processes, suggesting ore was deposited syndepositionally as a chemical sediment on the sea floor.