Strategies towards robust interpretations of in situ zircon Lu–Hf
isotope analyses
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Abstract
The combination of U–Pb and Lu–Hf compositions measured in zircon crystals is a remarkably powerful isotopic
couplet that provides measures on both the timing of mineral growth and the radiogenic enrichment of the source
from which the zircon grew. The U–Pb age documents the timing of zircon crystallization/recrystallization and Hf
isotopes inform on the degree to which the host melt was derived from a radiogenic reservoir (e.g. depleted
mantle) versus an unradiogenic reservoir (e.g. ancient continental crust), or some mixture of these sources. The
ease of generating large quantities of zircon U–Pb and Lu–Hf data has been in large part facilitated by instrument
advances. However, the dramatic increase in time constrained zircon Lu–Hf analyses in the Earth science community
has brought to the fore the importance of careful data collection and reduction workflows, onto which
robust geological interpretations may be based. In this work, we discuss the fundamentals of Lu–Hf isotopes in
zircon, which then allows us to provide a robust, accessible, methodology for the assessment of data quality.
Additionally, we discuss some novel techniques for: data visualization — that facilitates better transparency of
data interpretation; integration of geographic information—that may reveal spatial trends where temporal trends
were only apparent before; and some novel statistical evaluation tools — that may provide more rigorous interand
intra-sample comparisons.
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