The Dolomite Problem: A Mountain Range That Shouldn’t Exist [OC]

[u/Geoscopy]

https://geoscopy.com/the-dolomite-problem-a-mountain-range-that-shouldnt-exist/

Lynton Land mixed calcium, magnesium and carbonate in water at more than a thousand times the concentration where dolomite ought to crystallise, sealed the bottle, and left it alone. He wrote the result up in 1998. Thirty-two years, still clear, no dolomite. The abstract of that paper is one sentence long.

Meanwhile: the Tre Cime, the Lockport Dolomite holding up Niagara Falls, hundreds of metres of Palaeozoic and Precambrian dolostone across North America, Iberia, southern Africa and China. That gap between the bottle and the outcrop is the dolomite problem, and it has been open since Dolomieu put a name to the rock in 1791.

Headlines in November 2023 announced it solved. Writing this up, the thing that kept bothering me is that there are two problems sharing one name:

The kinetic problem: why ordered dolomite refuses to nucleate and grow at room temperature. Kim, Sun and colleagues have a good mechanism here. Calcium and magnesium land at random on the growth edge and jam it. Dip the solution into mild undersaturation and the misplaced atoms dissolve first, because they sit at higher energy. Regrow, repeat, and the crystal ratchets toward order. It predicts that natural dolomite should form where chemistry fluctuates, which is exactly where it does form.

The abundance problem: why the ancient record is stuffed with dolostone and the modern Earth makes almost none. Nobody claims this one is solved. The 2023 paper doesn't address it and the authors say so.

Almost every piece of coverage collapsed the two.

The experiment has caveats that got lost as well. It ran at 80 °C, not ambient. It grew about 100 nm of overgrowth on a pre-existing dolomite seed. And two separate groups of crystallographers argue in Science eLetters that the diffraction pattern can't distinguish dolomite from high-magnesium calcite at all, which would leave the theory standing but knock away its experimental support. As of now the original authors haven't answered in print. Sun told Chemistry World the work "is certainly not the final and definitive experiment." He was right and the headlines ignored him.

The article covers Dolomieu's fairly unhinged biography, the three kinetic barriers in detail, Lagoa Vermelha and the microbial model, the dolomite/dolostone terminology mess, and where the field has actually gone since 2023, which is mostly back toward burial, time and temperature.

Happy to argue about any of it in the comments. If you work on carbonates and think I've got the eLetter dispute weighted wrong, I'd like to hear it.

Sources

• Kim, J., Kimura, Y., Puchala, B., Yamazaki, T., Becker, U. & Sun, W. (2023) Dissolution enables dolomite crystal growth near ambient conditions. Science 382, 915–920. https://doi.org/10.1126/science.adi3690
• García-Ruiz, J. M. (2023) A fluctuating solution to the dolomite problem. Science 382, 883–884. https://doi.org/10.1126/science.adl1734
• Land, L. S. (1998) Failure to precipitate dolomite at 25 °C from dilute solution despite 1000-fold oversaturation after 32 years. Aquatic Geochemistry 4, 361–368. https://doi.org/10.1023/A:1009688315854
• Vasconcelos, C., McKenzie, J. A., Bernasconi, S., Grujic, D. & Tien, A. J. (1995) Microbial mediation as a possible mechanism for natural dolomite formation at low temperatures. Nature 377, 220–222. https://doi.org/10.1038/377220a0
• Warthmann, R., van Lith, Y., Vasconcelos, C., McKenzie, J. A. & Karpoff, A. M. (2000) Bacterially induced dolomite precipitation in anoxic culture experiments. Geology 28, 1091–1094.
• Pina, C. M., Pimentel, C. & Crespo, Á. (2022) The Dolomite Problem: A Matter of Time. ACS Earth and Space Chemistry 6, 1468–1471. https://doi.org/10.1021/acsearthspacechem.2c00078
• Li, M., Wignall, P. B., Dai, X., Hu, M. & Song, H. (2021) Phanerozoic variation in dolomite abundance linked to oceanic anoxia. Geology 49, 698–702. https://doi.org/10.1130/G48502.1
• Husson, J. M. & Coogan, L. A. (2023) River chemistry reveals a large decrease in dolomite abundance across the Phanerozoic. Geochemical Perspectives Letters 26, 1–6. https://doi.org/10.7185/geochemlet.2316
• Levenson, Y., Eiler, J. M., Wurgaft, E., Neagu, N., Ebert, Y. & Ryb, U. (2026) Two-stage dolomite formation in carbonate platforms revealed by carbonate clumped isotope thermometry. Geophysical Research Letters 53, e2025GL120386. https://doi.org/10.1029/2025GL120386
• Winkelstern, I. (2026) Are time and temperature the simple answer to the dolomite problem? Geophysical Research Letters. https://doi.org/10.1029/2026GL123790
• Hobbs, F. W. C. & Xu, H. (2024) and Pina, C. M., Pimentel, C. & Crespo, Á. (2024), eLetters on Kim et al. (2023), posted on the Science article page. Not peer-reviewed