Skip to main content Accessibility help

Unusual morphologies and the occurrence of pseudomorphs after ikaite (CaCO3·6H2O) in fast growing, hyperalkaline speleothems

  • L. P. Field (a1), A. E. Milodowski (a1), R. P. Shaw (a1), L. A. Stevens (a2), M. R. Hall (a1) (a2), A. Kilpatrick (a1), J. Gunn (a3), S. J. Kemp (a1) and M. A. Ellis (a1)...


Unusual speleothems, associated with hyperalkaline (pH > 12) groundwaters have formed within a shallow, abandoned railway tunnel at Peak Dale, Derbyshire, UK. The hyperalkaline groundwaters are produced by the leaching of a thin layer (<2 m) of old lime-kiln waste on the soil-bedrock surface above the tunnel by rainwater. This results in a different reaction and chemical process to that more commonly associated with the formation of calcium carbonate speleothems from Ca-HCO3-type groundwaters and degassing of CO2. Stalagmites within the Peak Daletunnel have grown rapidly (averaging 33 mm y–1), following the closure of the tunnel 70 years ago. They have an unusual morphology comprising a central sub-horizontally-laminated column of micro- to nano-crystalline calcium carbonate encompassed by an outer sub-vertical assymetricripple-laminated layer. The stalagmites are composed largely of secondary calcite forming pseudomorphs (<1 mm) that we believe to be predominantly after the 'cold climate' calcium carbonate polymorph, ikaite (calcium carbonate hexahydrate: CaCO3·6H2O), withminor volumes of small (<5 μm) pseudomorphs after vaterite. The tunnel has a near constant temperature of 8–9°C, which is slightly above the previously published crystallization temperatures for ikaite (<6°C). Analysis of a stalagmite actively growing at the time ofsampling, and preserved immediately within a dry nitrogen cryogenic vessel, indicates that following crystallization of ikaite, decomposition to calcite occurs rapidly, if not instantaneously. We believe this is the first occurrence of this calcium carbonate polymorph observed within speleothems.


Corresponding author



Hide All
Allison, V.C. (1923) The growth of stalagmites and stalactites. Journal of Geology, 31, 106125.
Baker, A., Genty, D., Dreybrodt, W., Barnes, W.L., Mockler, N.J. and Grapes, J. (1998) Testing theoretically predicted stalagmite growth rate with recent annually laminated samples: implications for past stalagmite deposition. Geochimica et Cosmochimica Acta, 62, 393404.
Baker, A., Proctor, C.J. and Barnes, W.L. (1999) Variations in stalagmite luminescence laminae structure at Poole's Cavern, England, AD 1910 ±1996: calibration of a palaeoprecipitation proxy. The Holocene, 9, 683688.
Baker, A., Smith, C.L., Jex, C., Fairchild, I.J., Genty, D. and Fuller, L. (2008) Annually laminated speleothems: a review. International Journal of Speleology, 37, 193206.
Banks, VI, Gunn, J. and Lowe, D.J. (2009) Stratigraphical influences on the limestone hydrogeol-ogy of the Wye catchment, Derbyshire. Quarterly Journal of Engineering Geology and Hydrogeology, 42, 211225.
Barnes, I., Presser, T.S., Saines, M., Dickson, P. and Van Groos, A.F.K. (1982) Geochemistry of highly basic calcium hydroxide groundwater in Jordan. Chemical Geology, 35, 147154.
Bischoff, J.L., Fitzpatrick, J.A. and Rosenbauer, R.J. (1993) The solubility and stabilization of ikaite (CaCCy6H2O) from 0° to 25°C: Environmental and paleoclimatic implications for thinolite tufa. Journal of Geology, 101, 2133.
Boch, R., Dietzel, M., Reichl, P., Leis, A., Baldermann, A., Mittermayer, F. and Pölt, P. (2015) Rapid ikaite (CaCO3'6H2O) crystallisation in a man-made river bed: Hydrogeochemical monitoring of a rarely documented mineral formation. Applied Geochemistry, 63, 366379.
Brunauer, S., Emmett, P.H. and Teller, E. (1938) Adsorption of gases in multimolecular layers. Journal of the American Chemical Society, 60, 309319.
Buchardt, B., Seaman,P., Stockmann, G., Vous, M., Wilken, U., Düwel, L., Kristiansen, A., Jenner, C., Whiticar, M. J., Kristensen, R.M. et al. (1997) Submarine columns of ikaite tufa. Nature, 390, 129130.
Dahl, K. and Buchardt, B. (2006) Monohydrocalcite in the arctic Ikka Fjord, SW Greenland: First reported marine occurrence. Journal of Sedimentary Research, 76, 460–71.
De Lurio, J.L. and Frakes, L.A. (1999) Glendonites as a paleoenvironmental tool: implications for early Cretaceous high latitude climates in Australia. Geochimica et Cosmochimica Acta, 63, 10391048.
Fairchild, I.J. and Baker, A. (2012) Speleothem Science: From Process to Past Environments. Wiley-Blackwell, Chichester, UK.
Frisia, S., Borsato, A., Fairchild, I.J., McDermott, F. and Selmo, E.M. (2002) Aragonite-calcite relationships in speleothems (Grotte de Clamouse, France): Enironment, fabrics and carbonate geochemistry. Journal of Sedimentary Research, 72, 687699.
Gagen, P.J. (1988) The evolution of quarried limestone rock slopes in the English Peak District. Unpublished PhD Thesis, CNAA at Manchester Polytechnic, UK.
Gagen, P.J. and Gunn, J. (1988) A geomorphological approach to limestone quarry restoration. Pp. 121142 in: Geomorphology in Environmental Planning (J.M. Hooke, editor). John Wiley and Sons, Chichester, UK.
Gaines, R.V., Skinner, C.W., Foord, E.E., Mason, B. and Rosenzweig, A. (1997) Dana's New Mineralogy: The System of Mineralogy of James Dwight and Edward Salisbury, 8th ed. Wiley, New York, 1872 pp.
Hansen, M.O., Buchardt, B., Kühl, M. and Elberling, B. (2011) The fate of the submarine Ikaite Tufa columns in Southwest Greenland under changing climate conditions. Journal of Sedimentary Research, 81, 553561.
Hartland, A., Domínguez-Villar, D., Baker, A., Gunn, J., Baalousha, M. and Yon, J.-N. (2010) The dripwaters and speleothems of Poole's Cavern: a review of recent and ongoing research. Cave and Karst Science, 36, 3746.
Hesse, K.F. and Kuppers, H. (1983) Refinement of the structure of Ikaite, CaCCy6H2O. Zeitschrift fUr Kristallographie, 163, 227231.
House, W.A. (1987) Inhibition of calcite crystal growth by inorganic phosphate. Journal of Colloid and Interface Science, 119, 505511.
Hu, Y.-B., Wolf-Gladrow, D.A., Dieckmann, G.S. Völker, C. and Nehrke, G. (2014) A laboratory study of ikaite (CaCO3-6H2O) precipitation as a function of pH, salinity, temperature and phosphate concentration. Marine Chemistry, 162, 1018.
Ito, T (1998) Factors controlling the transformation of natural ikaite from Shiowakka, Japan. Geochemical Journal, 32, 267273.
Liu, Z. and He, D. (1998) Special speleothems in cement-grouting tunnels and their implications of the atmospheric CO2 sink. Environmental Geology, 35, 258262.
Macleod, G., Fallick, A.E. and Hall, A.J. (1991) The mechanism of carbonate growth on concrete struc-tures, as elucidated by carbon and oxygen isotope analyses. Chemical Geology: Isotope Geoscience Section, 86, 335343.
Marland, G. (1975) The stability of CaCCy6H2O (ikaite). Geochimica et Cosmochimica Acta, 39, 8391.
McDermott, F. (2004) Palaeo-climate reconstruction from stable isotope variations in speleothems: a review. Quarternary Science Reviews, 23, 901918.
McMillan, E.A., Fairchild, I.J., Frisia, S., Borsato, A. and McDermott, F. (2005) Annual trace element cycles in calcite-aragonite speleothems: evidence of drought in the western Mediterranean 1200-1100 yr BP. Journal of Quaternary Science, 20, 423433.
Milodowski, A.E., Shaw, R.P and Stewart, D.I. (2013) The Harpur Hill Site: its geology, evolutionary history and a catalogue of materials present. British Geological Survey Report, CR/13/104. Available from:
Milodowski, A., Rushton, J., Purser, G., Rochelle, C., Kemp, S., Shaw, R. and Ellis, M. (2014) The formation of ikaite (CaCO3'6H2O) in hyperalkaline springs associated with the leaching of lime kiln waste. Goldschmidt Abstracts, p. 1697.[available at]. ISSN: 1042-7287.
Newton, K.E., Fairchild, I.J. and Gunn, J. (2015) Rates of calcite precipitation from hyperalkaline waters, Poole's Cavern, Derbyshire, UK. Cave and Karst Science, 42, 116124.
Omelon, C.R., Pollard, W.H. and Marion, G.M. (2000) Seasonal formation of ikaite (CaCO3-6H2O) in saline spring discharge at Expedition Fiord, Canadian High Arctic: Assessing conditional constraints for natural crystal growth. Geochimica et Cosmochimica Acta, 65, 14291437.
Ordnance Survey (2013) Ordnance Survey data Crown Copyright and database rights, 2013. Ordnance Survey Licence No. 100021290.
Parkhurst, D.L. and Appelo, C.A.J. (2013) Description of input and examples for PHREEQC Version 3 — A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. U.S. Geological Survey Techniques and Methods, 6. USGS.
Pauly, H. (1963) “Ikaite”, a new mineral from Greenland. Arctic, 16, 263264.
Pinsent, B.R.W., Pearson, L. and Roughton, F.J.W. (1956) The kinetics of combination of carbon dioxide with hydroxide ions. Transactions of the Faraday Society, 52, 15121520.
Railsback, L.B., Brook, G.A., Chen, J., Kalin, R. and Fleisher, C.J. (1994) Environmental controls on the petrology of a late Holocene speleothem from Botswana with annual layers of aragonite and calcite. Journal of Sedimentary Research A, 64, 147155.
Rodriguez-Blanco, J.D., Shaw, S. and Benning, L.G. (2011) The kinetics and mechanisms of amorphous calcium carbonate (ACC) crystallization to calcite, via vaterite. Nanoscale, 3, 265271.
Rodriguez-Blanco, J.D., Shaw, S., Bots, P., Roncal-Herrero, T and Benning, L.G. (2014) The role of Mg in the crystallisation of monohydrocalcite. Geochimica et Cosmochimica Acta, 127, 204220,
Roedder, E. (1968) The noncolloidal origin of “collo-form” textures in sphalerite ores. Economic Geology, 63, 451471.
Sánchez-Pastor, N., Oehlerich, M., Astilleros, J.M., Kaliwoda, M., Mayr, C.C., Fernández-Díaz, L. and Schmahl, W.W. (2016) Crystallization of ikaite and its pseudomorphic transformation into calcite: Ramen spectroscopy evidence. Geochimica et Cosmochimica Acta, 175, 271281.
Self, C.A. and Hill, C.A. (2003) How speleothems grow: an introduction to the ontogeny of cave minerals. Journal of Cave and Karst Studies, 65, 130151.
Shaikh, A.M. and Shearman, D J. (1987) On ikaite and the morphology of its pseudomorphs. in: Geochemistry of the Earth Surface and Processes of Mineral Formation (Rodriguez-Clemente, R., Tardy, Y., editors). Consejo Superior de Investigaciones Científicas Granada, Spain.
Shearman, D.J. and Smith, A.J. (1985) Ikaite, the parent mineral of jarrowite-type pseudomorphs. Proceedings of the Geologists’ Association, 96, 305314.
Shearman, D.J., McGugan, A., Stein, C. and Smith, A.J. (1989) Ikaite, CaCO3-6H2O, precursor of the thino-lites in the Quaternary tufas and tufa mounds of the Lahontan and Mono Lake Basins, western United States. Geological Society of America Bulletin, 101, 913917.
Spielhagen, R.F. and Tripati, A. (2009) Evidence from Svalbard for near-freezing temperatures and climate oscillations in the Arctic during the Paleocene and Eocene. Palaeogeography Palaeoclimatology, Palaeoecology, 278, 4856.
Sundqvist, H.S., Baker, A. and Holmgren, K. (2005) Luminescence variations in fast-growing stalagmites from Uppsala, Sweden. Geografiska Annaler: Series A, Physical Geography, 87, 539548.
Tucker, M. (2001) Sedimentary Petrology: An Introduction to the Origin of Sedimentary Rocks, 3rd ed. Blackwell, Oxford, UK.
UK Meteorological Office (2014) MIDAS Land Surface Stations data (1853-current), [Internet]. NCAS British Atmospheric Data Centre. Available from:
Waters, C.N., Waters, R.A., Barclay, W.J. and Davies, J. (2009) . lithostratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore) RR/09/01. British Geological Survey, Keyworth, Nottingham.



Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed