Timing of mineralization at the Navan Zn-Pb deposit: A post-Arundian age for Irish mineralization

Abstract

Navan is the largest of the Irish Zn-Pb deposits and contains some of the most important evidence for the inferred early timing of mineralization in Ireland (clasts of ore above a middle Carboniferous erosion surface). We have examined diagenetic fabrics within the main ore (pale beds) and the overlying erosion surface (Boulder Conglomerate) in order to determine the timing of mineralization. This diagenetic analysis (and particularly the presence of premineralization dolomite in the Boulder Conglomerate) has revealed that all of the mineralization postdates the erosion surface and therefore must be post-Arundian (345 Ma) in age. Furthermore, the Navan mineralization must be entirely epigene..