Carbonate clumped isotope abundance is an important paleothermometer, but measurement is difficult, slow, and subject to cardinal mass () interferences using isotope ratio mass spectrometry (IRMS). Here, we describe an optical spectroscopic measurement of carbonate clumped isotopes. We have adapted a tunable infrared laser differential absorption spectrometer (TILDAS) system to measure the abundances of four CO isotopologues used for clumped isotope thermometry. TILDAS achieves the same precision (0.01‰ SE) as IRMS measurements rapidly (∼50 min per carbonate analysis) and using small samples (<2 mg of calcite), without making assumptions about O abundance in the sample. A temperature calibration based on 406 analyses of CO produced by digestion of 51 synthetic carbonates equilibrated at 6° to 1100°C is consistent with results for natural carbonates and previous calibrations. Our system results were indistinguishable from IRMS systems after replicating the InterCarb interlaboratory calibration. Measurement by TILDAS could change the landscape for clumped isotope analysis.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1126/sciadv.abq0611 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Midinfrared Cavity-Enhanced Two-Photon Absorption Spectroscopy for Selective Detection of Trace Gases.
Anal Chem
January 2025
Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China.
Detection of trace gases, such as radioactive carbon dioxide, clumped isotopes, and reactive radicals, is of great interest and poses significant challenges in various fields. Achieving both high selectivity and high sensitivity is essential in this context. We present a highly selective molecular spectroscopy method based on comb-locked, mid-infrared, cavity-enhanced, two-photon absorption.
View Article and Find Full Text PDFA hybrid model for refining gross primary productivity estimation by integrating multiple environmental factors.
MethodsX
June 2025
State Key Laboratory of Remote Sensing Science, Beijing Normal University, Beijing 100875, China.
Article Synopsis
- Environmental factors contribute to uncertainty in estimating gross primary productivity (GPP) in current light use efficiency (LUE) models because basic formulas can't capture complex environmental impacts.
- A new hybrid model called TL-CRF combines the random forest (RF) technique with a two-leaf LUE model to account for various ecological stressors and seasonal variations in canopy structure.
- This integration enhances the accuracy of GPP estimates by merging strengths from both process-based and data-driven approaches.
Avalanching behavior of magnetic granular mixtures.
Phys Rev E
October 2024
University of Maryland, College Park, Maryland 20742, USA.
We conducted avalanching experiments with an external magnetic field and granular samples of different grain sizes (3.18 mm, 6.35 mm, and 8.
View Article and Find Full Text PDFImproving global gross primary productivity estimation using two-leaf light use efficiency model by considering various environmental factors via machine learning.
Sci Total Environ
December 2024
Key Laboratory of West China's Environment Systems (Ministry of Education), College of Earth and Environmental Sciences, Observation and Research Station on Eco-Environment of Frozen Ground in the Qilian Mountains, Lanzhou University, Lanzhou 730000, China.
Distinguishing gross primary productivity (GPP) into sunlit (GPP) and shaded (GPP) components is critical for understanding the carbon exchange between the atmosphere and terrestrial ecosystems under climate change. Recently, the two-leaf light use efficiency (TL-LUE) model has proven effective for simulating global GPP and GPP. However, no known physical method has focused on integrating the overall constraint of intricate environmental factors on photosynthetic capability, and seasonal differences in the foliage clumping index (CI), which most likely influences GPP estimation in LUE models.
View Article and Find Full Text PDFReconstruction of Phanerozoic climate using carbonate clumped isotopes and implications for the oxygen isotopic composition of seawater.
Proc Natl Acad Sci U S A
September 2024
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125.
The oxygen isotope ratio O/O (expressed as a δO value) in marine sedimentary rocks has increased by ~8‰ from the early Paleozoic to modern times. Interpretation of this trend is hindered by ambiguities in the temperature of formation of the carbonate, the δO, and the effects of postdepositional diagenesis. Carbonate clumped isotope measurements, a temperature proxy, offer constraints on this problem.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!