Frontiers of Carbonate Clumped Isotope Thermometry

Abstract

Carbonate minerals contain stable isotopes of carbon and oxygen with different masses whose abundances and bond arrangement are governed by thermodynamics. The clumped isotopic value Δi is a measure of the temperature-dependent preference of heavy C and O isotopes to clump, or bond with or near each other, rather than with light isotopes in the carbonate phase. Carbonate clumped isotope thermometry uses Δi values measured by mass spectrometry (Δ47, Δ48) or laser spectroscopy (Δ638) to reconstruct mineral growth temperature in surface and subsurface environments independent of parent water isotopic composition. Two decades of analytical and theoretical development have produced a mature temperature proxy that can estimate carbonate formation temperatures from 0.5 to 1,100°C, with up to 1–2°C external precision (2 standard error of the mean). Alteration of primary environmental temperatures by fluid-mediated and solid-state reactions and/or Δi values that reflect nonequilibrium isotopic fractionations reveal diagenetic history and/or mineralization processes. Carbonate clumped isotope thermometry has contributed significantly to geological and biological sciences, and it is poised to advance understanding of Earth's climate system, crustal processes, and growth environments of carbonate minerals. ▪ Clumped heavy isotopes in carbonate minerals record robust temperatures and fluid compositions of ancient Earth surface and subsurface environments. ▪ Mature analytical methods enable carbonate clumped Δ47, Δ48, and Δ638 measurements to address diverse questions in geological and biological sciences. ▪ These methods are poised to advance marine and terrestrial paleoenvironment and paleoclimate, tectonics, deformation, hydrothermal, and mineralization studies. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 51 is May 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Writ in water—Unwritten histories obtained from carbonate deposits in ancient water systems

“…This has been applied in a bath complex in Djebel Oust, Tunisia, but is usually difficult because the water composition cannot be accurately known and because of the nonequilibrium deposition of carbonate (Curie et al, 2018). Clumped isotope thermometry can be used to determine the temperature of carbonate deposition independent of water composition (Eiler, 2011; Huntington & Petersen, 2023) and is promising for application on aqueduct carbonates but has so far only been applied to natural deposits (e.g., Kele et al, 2015; Kluge et al, 2018).…”

Joint application of fluid inclusion and clumped isotope (∆47) thermometry unravels the complexity of thermal and fluid‐flow history reconstruction in sedimentary basins—Upper Triassic Chaunoy Formation reservoirs (Paris Basin)

“…Conversely, water presence, composition and pressure exert only modest influence on ∆ 47 reordering rates. Therefore, it is possible to make meaningful predictions about carbonate ∆ 47 reordering if a well‐constrained thermal history is available, even when fluid composition and pressure are unknown (Brenner et al, 2018; Huntington & Petersen, 2023).…”

“…This process occurs in samples exposed to significant heating for an extended period and primarily depends on the temperature–time path followed by the samples and on the mineralogy of the carbonate phase considered (e.g. Brenner et al, 2018; Hemingway & Henkes, 2021; Huntington & Petersen, 2023; Lawson et al, 2018; Lloyd et al, 2018; Mangenot et al, 2019; Passey & Henkes, 2012; Stolper & Eiler, 2015).…”

Robust land surface temperature record for north China over the past 21,000 years

“…In addition, the δ 18 O values of land snail shells (δ 18 O shell ) are used to reconstruct past EASM climate, although the δ 18 O shell actually relates to both temperature and precipitation (47,48). The ∆ 47 yields the absolute temperature at which the carbonate was formed, independent of the δ 18 O composition of the source water (49). However, available studies so far indicate that snail shells can generate ∆ 47 -based temperatures that are higher than MAAT, as well as the mean air temperature during the snail's active season (50)(51)(52).…”