Lu-Hf ratios of crustal rocks and their bearing on zircon Hf isotope model ages: The effects of accessories

All other factors being equal, the calculation of zircon Hf two stage model ages (TDM Hf) depends on the particular Lu/Hf value assumed for the magmatic source, the effect being more pronounced as the age difference between zircon and magmatic source increases. It is generally considered that the Lu/Hf measured in the zircon-hosting rock does not represent the composition of the source because of potential garnet or zircon fractionation....