A unified clumped isotope thermometer calibration (0.5-1100C) using
carbonate-based standardization
Abstract
The potential for carbonate clumped isotope thermometry to independently
constrain both the formation temperature (T∆47 ) of carbonate minerals
and fluid oxygen isotope composition allows insight into long-standing
questions in the Earth sciences, but remaining discrepancies between
calibration schemes hamper interpretation of T∆47 measurements. To
address discrepancies between calibrations, we designed and analyzed a
sample suite (41 total samples) with broad applicability across the
geosciences, with an exceptionally wide range of formation temperatures,
precipitation methods, and mineralogies. We see no statistically
significant offset between sample types, although comparison of calcite
and dolomite remains inconclusive. When data are reduced identically,
the regression defined by this study is nearly identical to that defined
by four previous calibration studies that used carbonate-based
standardization; we combine these data to present a composite
carbonate-standardized regression equation. Agreement across a wide
range of temperature and sample types demonstrates a unified, broadly
applicable clumped isotope thermometer calibration.