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Clumped isotopes

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Clumped isotopes are heavy isotopes that are bonded to other heavy isotopes. The relative abundance of clumped isotopes (and multiply-substituted isotopologues) in molecules such as methane, nitrous oxide, and carbonate is an area of active investigation. The carbonate clumped-isotope thermometer, or "C–O order/disorder carbonate thermometer", is a new approach for paleoclimate reconstruction, based on the temperature dependence of the clumping of C and O into bonds within the carbonate mineral lattice. This approach has the advantage that the O ratio in water is not necessary (different from the δO approach), but for precise paleotemperature estimation, it also needs very large and uncontaminated samples, long analytical runs, and extensive replication. Commonly used sample sources for paleoclimatological work include corals, otoliths, gastropods, tufa, bivalves, and foraminifera. Results are usually expressed as Δ47 (said as "cap 47"), which is the deviation of the ratio of isotopologues of CO2 with a molecular weight of 47 to those with a weight of 44 from the ratio expected if they were randomly distributed.

Background

Terminology

Molecules made up of elements with multiple isotopes can vary in their isotopic composition; these variant molecules are called isotopologues. For example, consider the isotopologues of carbon dioxide. oxygen has three stable isotopes (O, O and O) and carbon has two (C, C).A CO2 molecule (composed only with most abundant isotopes of constituent elements) is called a monoisotopic species. When only one atom is replaced with heavy isotope of any constituent element (ie, CO2), it is called a singly-substituted species. Likewise, when two atoms are simultaneously replaced with heavier isotopes (eg., COO), the it is called a doubly substituted or also a multiply substituted isotopologue. The multiply-substituted isotopologue COO contains a bond between two of these heavier isotopes (C and O), which is a "clumped" isotope bond.

The abundance of masses for a given molecule (e.g. CO2) can be predicted using the relative abundance of isotopes of its constituent atoms (C/C, O/O and O/O). The relative abundance of each isotopologue (e.g. mass-47 CO2) is proportional to the relative abundance of each isotopic species.

R/R = (2×+2×+)/()

This predicted abundance assumes a non-biased stochastic distribution of isotopes, natural materials tend to deviate from these stochastic values, the study of which forms the basis of clumped isotope geochemistry.

When a heavier isotope substitutes for a lighter one (e.g., O for O), the chemical bond's vibration will be slower, lowering its zero-point energy. In other words, thermodynamic stability is related to the isotopic composition of the molecule.

CO3 (≈98.2%), CO3 (≈1.1%), COO2 (≈0.6%) and COO2 (≈0.11%) are the most abundant isotopologues (≈99%) of carbonate ion, controlling the bulk δC, δO and δO values in natural carbonate minerals. Each of these isopotologes has different thermodynamic stability. For a carbonate crystal at thermodynamic equilibrium, the relative abundances of the carbonate ion isotopologues is controlled by reactions such as:

CO3 + COO2 ⇌ CO3 + COO2 (Reaction 1)

The equilibrium constants for these reactions are temperature-dependent, with a tendency for heavy isotopes to "clump" with each other (increasing the proportions of multiply substituted isotopologues) as temperature decreases. Reaction 1 will be driven to the right with decreasing temperature, to the left with increasing temperature. Therefore, the equilibrium constant for this reaction can be used as an paleotemperature indicator, as long as the temperature dependence of this reaction and the relative abundances of the carbonate ion isotopologues are known.

Differences from the conventional δO analysis

In conventional δO analysis, both the δO values in carbonates and water are needed to estimate paleoclimate. However, for many times and places, the δO in water can only be inferred, and also the O/O ratio between carbonate and water may vary with the change in temperature. Therefore, the accuracy of the thermometer may be compromised.

Whereas for the carbonate clumped-isotope thermometer, the equilibrium is independent of the isotope compositions of waters from which carbonates grew. Therefore, the only information needed is the abundance of bonds between rare, heavy isotopes within the carbonate mineral.

Methods

  1. Extract CO2 from carbonates by reaction with anhydrous phosphoric acid. (there is no direct way to measure the abundance of CO3s in with high enough precision). The phosphoric acid temperature is often held between 25° and 90 °C and can be as high as 110 °C.
  2. Purify the CO2 that has been extracted. This step removes contaminant gases like hydrocarbons and halocarbons which can be removed by gas chromatography.
  3. Mass spectrometric analyses of purified CO2, to obtain δC, δO, and Δ47 (abundance of mass-47 CO2) values. (Precision needs to be as high as ≈10, for the isotope signals of interest are often less than ≈10)

Applications

Paleoenvironment

Clumped isotopes analyses have traditionally been used in lieu of conventional δO analyses when the δO of seawater or source water is poorly constrained. While conventional δO analysis solves for temperature as a function of both carbonate and water δO, clumped isotope analyses can provide temperature estimates that are independent of the source water δO. Δ47-derived temperature can then be used in conjunction with carbonate δO to reconstruct δO of the source water, thus providing information on the water with which the carbonate was equilibrated.

Clumped isotope analyses thus allow for estimates of two key environmental variables: temperature and water δO. These variables are especially useful for reconstructing past climates, as they can provide information on a wide range of environmental properties. For example, temperature variability can imply changes in solar irradiance, greenhouse gas concentration, or albedo, while changes in water δO can be used to estimate changes in ice volume, sea level, or rainfall intensity and location.

Studies have used temperatures derived from clumped isotopes for varied and numerous paleoclimate applications — to constrain δO of past seawater, pinpoint the timing of icehouse-hothouse transitions, track changes in ice volume through an ice age, and to reconstruct temperature changes in ancient lake basins.

Paleoaltimetry

Clumped isotope analyses have recently been used to constrain the paleoaltitude or uplift history of a region. Air temperature decreases systematically with altitude throughout the troposphere (see lapse rate). Due to the close coupling between lake water temperature and air temperature, there is a similar decrease in lake water temperature as altitude increases. Thus, variation in water temperature implied by Δ47 could indicate changes in lake altitude, driven by tectonic uplift or subsidence. Two recent studies derive the timing of the uplift of the Andes Mountains and the Altiplano Plateau, citing sharp decreases in Δ47-derived temperatures as evidence of rapid tectonic uplift.

Atmospheric science

Measurements of Δ47 can be used to constrain natural and synthetic sources of atmospheric CO2, (e.g. respiration and combustion), as each of these processes are associated with different average Δ47 temperatures of formation.

Paleobiology

Measurements of Δ47 can be used to better understand the physiology of extinct organisms, and to place constraints on the early development of endothermy, the process by which organisms regulate their body temperature. Prior to the development of clumped isotope analysis, there was no straightforward way to estimate either the body temperature or body water δO of extinct animals. Eagle et al., 2010 measure Δ47 in bioapatite from a modern Indian elephant, white rhinoceros, Nile crocodile and American alligator. These animals were chosen as they span a wide range in internal body temperatures, allowing for the creation of a mathematical framework relating Δ47 of bioapatite and internal body temperature. This relationship has been applied to analyses of fossil teeth, in order to predict the body temperatures of a woolly mammoth and a sauropod dinosaur. The latest Δ47 temperature calibration for (bio)apatite of Löffler et al. 2019 covers a wide temperature range of 1-80°C and was applied to a fossil megalodon shark tooth for calculating seawater temperatures and δO values.

Petrology and metamorphic alteration

A key premise of most clumped isotope analyses is that samples have retained their primary isotopic signatures. However, isotopic resetting or alteration, resulting from elevated temperature, can provide a different type of information about past climates. For example, when carbonate is isotopically reset by high temperatures, measurements of Δ47 can provide information about the duration and extent of metamorphic alteration. In one such study, Δ47 from late Neoproterozoic Doushantou cap carbonate is used to assess the temperature evolution of the lower crust in southern China.

Cosmochemistry

Primitive meteorites have been studied using measurements of Δ47. These analyses also assume that the primary isotopic signature of the sample has been lost. In this case, measurements of Δ47 instead provide information on the high-temperature event that isotopically reset the sample. Existing Δ47 analyses on primitive meteorites have been used to infer the duration and temperature of aqueous alteration events, as well as to estimate the isotopic composition of the alteration fluid.

Ore deposits

An emerging body of work highlights the application potential for clumped isotopes to reconstruct temperature and fluid properties in hydrothermal ore deposits. In mineral exploration, delineation of the heat footprint around an ore body provides critical insight into the processes that drive transport and deposition of metals. During proof of concept studies, clumped isotopes were used to provide accurate temperature reconstructions in epithermal, sediment hosted, and Mississippi Valley Type (MVT) deposits. These case studies are supported by measurement of carbonates in active geothermal settings.

Limitations

The temperature dependent relationship is subtle (−0.0005%/°C).

COO2 is a rare isotopologue (≈60 ppm ).

Therefore, to obtain adequate precision, this approach requires long analyses (≈2–3 hours) and very large and uncontaminated samples.

Clumped isotope analyses assume that measured Δ47 is composed of COO2, the most common isotopologue of mass 47. Corrections to account for less common isotopologues of mass 47 (e.g. COO O) are not completely standardized between labs.

See also

References

  1. ^ Eiler, J.M. (2007). ""Clumped-isotope" geochemistry—The study of naturally-occurring, multiply-substituted isotopologues". Earth and Planetary Science Letters. 262 (3–4): 309–327. Bibcode:2007E&PSL.262..309E. doi:10.1016/j.epsl.2007.08.020.
  2. Lea, D.W. (2014). "8.14 - Elemental and Isotopic Proxies of Past Ocean Temperatures". In Holland, H.D.; Turekian, K.K. (eds.). Treatise on Geochemistry, Second Edition. Vol. 8. Oxford: Elsevier. pp. 373–397. doi:10.1016/B978-0-08-095975-7.00614-8. ISBN 9780080983004.
  3. Ghosh, P.; Adkins, J.; Affek, H.; et al. (2006). "C-O bonds in carbonate minerals: A new kind of paleothermometer". Geochimica et Cosmochimica Acta. 70 (6): 1439–1456. Bibcode:2006GeCoA..70.1439G. doi:10.1016/j.gca.2005.11.014.
  4. Ghosh, P.; Eiler, J.; Campana, S.E.; Feeney, R.F. (2007). "Calibration of the carbonate 'clumped isotope' paleothermometer for otoliths". Geochimica et Cosmochimica Acta. 71 (11): 2736–2744. Bibcode:2007GeCoA..71.2736G. doi:10.1016/j.gca.2007.03.015.
  5. Tripati, A.K.; Eagle, R.A.; Thiagarajan, N.; et al. (2010). "C-O isotope signatures and 'clumped isotope' thermometry in foraminifera and coccoliths". Geochimica et Cosmochimica Acta. 74 (20): 5697–5717. Bibcode:2010GeCoA..74.5697T. doi:10.1016/j.gca.2010.07.006.
  6. Affek, Hagit (2012). "Clumped isotope paleothermometry: Principles, applications, and challenges". Reconstructing Earth's Deep-Time Climate—The State of the Art in 2012, Paleontological Society Short Course, November 3, 2012. 8: 101–114.
  7. Urey, H.C. (1947). "The thermodynamic properties of isotopic substances". J. Chem. Soc. London: 562–581. doi:10.1039/JR9470000562. PMID 20249764.
  8. Bigeleisen, J.; Mayer, M.G. (1947). "Calculation of equilibrium constants for isotopic exchange reactions". J. Chem. Phys. 15 (5): 261–267. Bibcode:1947JChPh..15..261B. doi:10.1063/1.1746492. hdl:2027/mdp.39015074123996.
  9. Wang, Z., Schauble, E.A., Eiler, J.M., 2004. Equilibrium thermodynamics of multiply substituted isotopologues of molecular gases. Geochim. Cosmochim. Acta 68, 4779–4797.
  10. Chappell, J., Shackleton, N.J., 1986. Oxygen isotopes and sea level. Nature 324, 137–140.
  11. C. Waelbroeck, L. Labeyrie, E. Michel, et al., (2002) Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. Quaternary Science Reviews. 21: 295-305
  12. McCrea, J.M., 1950. On the isotopic chemistry of carbonates and a paleotemperature scale. J. Chem. Phys. 18, 849–857.
  13. Swart, P.K., Burns, S.J., Leder, J.J., 1991. Fractionation of the stable isotopes of oxygen and carbon in carbon dioxide during the reaction of calcite with phosphoric acid as a function of temperature and technique. Chem. Geol. (Isot. Geosci. Sec.) 86, 89–96.
  14. ^ Eiler, John M. (2011-12-01). "Paleoclimate reconstruction using carbonate clumped isotope thermometry". Quaternary Science Reviews. 30 (25–26): 3575–3588. Bibcode:2011QSRv...30.3575E. doi:10.1016/j.quascirev.2011.09.001. ISSN 0277-3791.
  15. Wacker, Ulrike; Rutz, Tanja; Löffler, Niklas; Conrad, Anika C.; Tütken, Thomas; Böttcher, Michael E.; Fiebig, Jens (December 2016). "Clumped isotope thermometry of carbonate-bearing apatite: Revised sample pre-treatment, acid digestion, and temperature calibration". Chemical Geology. 443: 97–110. Bibcode:2016ChGeo.443...97W. doi:10.1016/j.chemgeo.2016.09.009.
  16. ^ Löffler, N.; Fiebig, J.; Mulch, A.; Tütken, T.; Schmidt, B.C.; Bajnai, D.; Conrad, A.C.; Wacker, U.; Böttcher, M.E. (May 2019). "Refining the temperature dependence of the oxygen and clumped isotopic compositions of structurally bound carbonate in apatite". Geochimica et Cosmochimica Acta. 253: 19–38. Bibcode:2019GeCoA.253...19L. doi:10.1016/j.gca.2019.03.002. S2CID 107992832.
  17. Eiler, J.M.; Schauble, E. (2004). "OCO in earth's atmosphere" (PDF). Geochim. Cosmochim. Acta. 68 (23): 4767–4777. Bibcode:2004GeCoA..68.4767E. doi:10.1016/j.gca.2004.05.035.
  18. ^ Huntington, K. W.; Budd, D. A.; Wernicke, B. P.; Eiler, J. M. (2011-09-01). "Use of Clumped-Isotope Thermometry To Constrain the Crystallization Temperature of Diagenetic Calcite". Journal of Sedimentary Research. 81 (9): 656–669. Bibcode:2011JSedR..81..656H. doi:10.2110/jsr.2011.51. ISSN 1527-1404.
  19. Came, Rosemarie E.; Eiler, John M.; Veizer, Ján; Azmy, Karem; Brand, Uwe; Weidman, Christopher R. (September 2007). "Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era" (PDF). Nature. 449 (7159): 198–201. Bibcode:2007Natur.449..198C. doi:10.1038/nature06085. ISSN 1476-4687. PMID 17851520. S2CID 4388925.
  20. Finnegan, S.; Bergmann, K. D.; Eiler, J.; Jones, D. S.; Fike, D. A.; Eisenman, I. L.; Hughes, N.; Tripati, A. K.; Fischer, W. W. (2010-12-01). "Constraints on the duration and magnitude of Late Ordovician-Early Silurian glaciation and its relationship to the Late Ordovician mass extinction from carbonate clumped isotope paleothermometry". AGU Fall Meeting Abstracts. 54: B54B–04. Bibcode:2010AGUFM.B54B..04F.
  21. Santi, L. M.; Arnold, A. J.; Ibarra, D. E.; Whicker, C. A.; Mering, J. A.; Lomarda, R. B.; Lora, J. M.; Tripati, A. (2020-11-01). "Clumped isotope constraints on changes in latest Pleistocene hydroclimate in the northwestern Great Basin: Lake Surprise, California". GSA Bulletin. 132 (11–12): 2669–2683. Bibcode:2020GSAB..132.2669S. doi:10.1130/B35484.1. ISSN 0016-7606.
  22. Mering, John Arthur (2015). New constraints on water temperature at Lake Bonneville from carbonate clumped isotopes (Master of Science in Geochemistry thesis). University of California, Los Angeles. ProQuest 1707901550.
  23. ^ Ghosh, Prosenjit; Garzione, Carmala N.; Eiler, John M. (2006-01-27). "Rapid Uplift of the Altiplano Revealed Through 13C-18O Bonds in Paleosol Carbonates". Science. 311 (5760): 511–515. Bibcode:2006Sci...311..511G. doi:10.1126/science.1119365. ISSN 0036-8075. PMID 16439658. S2CID 129743191.
  24. ^ Huntington, K. W.; Wernicke, B. P.; Eiler, J. M. (2010-06-01). "Influence of climate change and uplift on Colorado Plateau paleotemperatures from carbonate clumped isotope thermometry" (PDF). Tectonics. 29 (3): TC3005. Bibcode:2010Tecto..29.3005H. doi:10.1029/2009TC002449. ISSN 1944-9194.
  25. Quade, Jay; Breecker, Daniel O.; Daëron, Mathieu; Eiler, John (2011-02-01). "The paleoaltimetry of Tibet: An isotopic perspective". American Journal of Science. 311 (2): 77–115. Bibcode:2011AmJS..311...77Q. doi:10.2475/02.2011.01. ISSN 0002-9599. S2CID 129751114.
  26. Hren, Michael T.; Sheldon, Nathan D. (2012-07-01). "Temporal variations in lake water temperature: Paleoenvironmental implications of lake carbonate δ18O and temperature records". Earth and Planetary Science Letters. 337–338: 77–84. Bibcode:2012E&PSL.337...77H. doi:10.1016/j.epsl.2012.05.019. ISSN 0012-821X.
  27. Garzione, Carmala N.; Hoke, Gregory D.; Libarkin, Julie C.; Withers, Saunia; MacFadden, Bruce; Eiler, John; Ghosh, Prosenjit; Mulch, Andreas (2008-06-06). "Rise of the Andes". Science. 320 (5881): 1304–1307. Bibcode:2008Sci...320.1304G. doi:10.1126/science.1148615. ISSN 0036-8075. PMID 18535236. S2CID 21288149.
  28. Eiler, John M.; Schauble, Edwin (2004-12-01). "18O13C16O in Earth's atmosphere". Geochimica et Cosmochimica Acta. 68 (23): 4767–4777. Bibcode:2004GeCoA..68.4767E. doi:10.1016/j.gca.2004.05.035. ISSN 0016-7037.
  29. Laskar, Amzad H.; Mahata, Sasadhar; Liang, Mao-Chang (2016). "Identification of Anthropogenic CO2 Using Triple Oxygen and Clumped Isotopes". Environmental Science & Technology. 50 (21): 11806–11814. Bibcode:2016EnST...5011806L. doi:10.1021/acs.est.6b02989. PMID 27690222.
  30. ^ Eagle, Robert A.; Schauble, Edwin A.; Tripati, Aradhna K.; Tütken, Thomas; Hulbert, Richard C.; Eiler, John M. (2010-06-08). "Body temperatures of modern and extinct vertebrates from 13C-18O bond abundances in bioapatite". Proceedings of the National Academy of Sciences. 107 (23): 10377–10382. Bibcode:2010PNAS..10710377E. doi:10.1073/pnas.0911115107. ISSN 0027-8424. PMC 2890843. PMID 20498092.
  31. Eagle, Robert A.; Tütken, Thomas; Martin, Taylor S.; Tripati, Aradhna K.; Fricke, Henry C.; Connely, Melissa; Cifelli, Richard L.; Eiler, John M. (2011-07-22). "Dinosaur Body Temperatures Determined from Isotopic (13C-18O) Ordering in Fossil Biominerals". Science. 333 (6041): 443–445. Bibcode:2011Sci...333..443E. doi:10.1126/science.1206196. ISSN 0036-8075. PMID 21700837. S2CID 206534244.
  32. Passey, Benjamin H.; Henkes, Gregory A. (2012-10-15). "Carbonate clumped isotope bond reordering and geospeedometry". Earth and Planetary Science Letters. 351–352: 223–236. Bibcode:2012E&PSL.351..223P. doi:10.1016/j.epsl.2012.07.021. ISSN 0012-821X.
  33. Guo, Weifu; Eiler, John M. (2007-11-15). "Temperatures of aqueous alteration and evidence for methane generation on the parent bodies of the CM chondrites". Geochimica et Cosmochimica Acta. 71 (22): 5565–5575. Bibcode:2007GeCoA..71.5565G. CiteSeerX 10.1.1.425.1442. doi:10.1016/j.gca.2007.07.029. ISSN 0016-7037.
  34. Halevy, Itay; Fischer, Woodward W.; Eiler, John M. (2011-10-11). "Carbonates in the Martian meteorite Allan Hills 84001 formed at 18 ± 4 °C in a near-surface aqueous environment". Proceedings of the National Academy of Sciences. 108 (41): 16895–16899. Bibcode:2011PNAS..10816895H. doi:10.1073/pnas.1109444108. ISSN 0027-8424. PMC 3193235. PMID 21969543.
  35. ^ Mering, John; Barker, Shaun; Huntington, Katherine; Simmons, Stuart; Dipple, Gregory; Andrew, Benjamin; Schauer, Andrew (2018-12-01). "Taking the Temperature of Hydrothermal Ore Deposits Using Clumped Isotope Thermometry". Economic Geology. 113 (8): 1671–1678. Bibcode:2018EcGeo.113.1671M. doi:10.5382/econgeo.2018.4608. ISSN 0361-0128. S2CID 135261236.
  36. Kirk, Ruth; Marca, Alina; Myhill, Daniel J.; Dennis, Paul F. (2018-01-01). "Clumped isotope evidence for episodic, rapid flow of fluids in a mineralized fault system in the Peak District, UK". Journal of the Geological Society. 176 (3): jgs2016–117. doi:10.1144/jgs2016-117. ISSN 0016-7649. S2CID 133785532.
  37. Kluge, Tobias; John, Cédric M.; Boch, Ronny; Kele, Sándor (2018). "Assessment of Factors Controlling Clumped Isotopes and δ18O Values of Hydrothermal Vent Calcites". Geochemistry, Geophysics, Geosystems. 19 (6): 1844–1858. Bibcode:2018GGG....19.1844K. doi:10.1029/2017GC006969. hdl:10044/1/63564. ISSN 1525-2027. S2CID 135107115.
  38. Kele, Sándor; Breitenbach, Sebastian F.M.; Capezzuoli, Enrico; Meckler, A. Nele; Ziegler, Martin; Millan, Isabel M.; Kluge, Tobias; Deák, József; Hanselmann, Kurt; John, Cédric M.; Yan, Hao; Liu, Zaihua; Bernasconi, Stefano M. (2015). "Temperature dependence of oxygen- and clumped isotope fractionation in carbonates: A study of travertines and tufas in the 6–95°C temperature range" (PDF). Geochimica et Cosmochimica Acta. 168: 172–192. Bibcode:2015GeCoA.168..172K. doi:10.1016/j.gca.2015.06.032.
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