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.

Pedogenic carbonate is widespread at mid latitudes where combined warm and dry conditions favor soil carbonate growth from spring to fall. The mechanisms and tempo of pedogenic carbonate formation are more ambiguous in the tropics, where longer periods of soil water saturation and higher soil respiration enhance calcite dissolution. This paper provides bulk and clumped isotope values from Quaternary and Miocene pedogenic carbonates in the tropical monsoonal domain of Myanmar where annual rainfall reaches up to 1700 mm. We show that carbonate growth in Myanmar is delayed to the coldest months of the year by sustained rainfall from mid spring to late fall. We propose that high soil moisture year-round in the tropical domain makes carbonate growth more episodic than in temperate ecosystems, and particularly sensitive to the seasonal distribution of rainfall. This sensitivity is also enhanced by high winter temperatures, allowing carbonate growth to occur outside the warmest months of the year. This high sensitivity is expected to be more prominent in the geological record during times with higher temperatures and greater expansion of the tropical realm. The winter bias in TD47 values found in Burmese soils, unique for pedogenic carbonates, constitute a potential signature for past tropical monsoonal (warm summer-wet) climates in paleosols, and are also found in our Miocene samples.