Hawkins Hill was 'the richest mine on earth' during the 1870's. The Hill End trough-fill sequence is currently favoured as the main source of mineralisation and this is consistent with mass balance calculations and sulphur isotope and fluid inclusion data. Thus local remobilisation is not the main source of metal in the quartz veins and we favour remobilisation and mixing of syngenetic sulphide and other background rock lead as the viable alternative. Variable mixing sources at slightly different times could acciount for the two isotope populations in the quartz veins. Veins consist of quartz, carbonates, muscovite and chlorite, accompanied by lesser pyrite, gold, pyrrhotite, chalcopyrite, sphalerite and galena.
Hostrock alteration is characterised by the development of chlorite and carbonate.
The differences in Pb isotopic composition for the vein systems suggest that they were derived from different sources, perhaps at slightly different times. Go back to the TOP Lead-lead isotope ratio plot of Hill End samples. Mid Devonian E-W folding and cleavage formation. Early Carboniferous deformation. Intrusion of Post-orogenic granitoids.