One of the most useful attributes of speleothems (and the one that sets them apart from most other palaeoclimate archives) is their amenability to precise and accurate radiometric dating. This is achieved through measurement of the radioactive decay of minute (often parts per million or less) quantities of natural Uranium in the calcite crystal lattice using sensitive mass spectrometers.
By far the most widely used method in this context measures intermediate daughter products in the U-series decay chain, primarily 230Th and 234U. This is the so-called U-Th or U-series dating method.
In ideal circumstances the U-Th method produces ages with a precision of 1% or less for samples up to around 600, 000 years in age, after which point the system has regained isotopic equilibrium and dating of older material is usually not possible. Here are a couple of useful papers on the method on a review and the other documenting the 'state of the art':
Richards, D.A., Dorale, J.A. (2003) Uranium-series chronology and environmental applications of speleothems. Reviews in Mineralogy and Geochemistry 51, 407-460.
Cheng et al. (2013) Improvements in 230Th dating, 230Th and 234U half-life values, and U-Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. Earth and Planetary Science Letters 371, 82-91.
In recent years there has been a major push to develop methods for dating older speleothems - those beyond the range of U-Th methods. For this we use the much longer lived decay of Uranium to Lead (U-Pb). This is an area in which the University of Melbourne team has invested significant time and resources to the extent that the methodology is not routine and processing hundreds of samples per year. Here are some useful papers for further reading:
Sniderman, K., Woodhead, J., Hellstrom, J., Jordan, G.J., Drysdale, J.J., Porch, N (2016) The Pliocene as a reversal of late Neogene acidification. P.N.A.S. 113, 1999-2004.
Woodhead et al. (2006) U-Pb geochronology of speleothems by MC-ICPMS. Quaternary Geochronology 1, 208-221.
Woodhead et al. (2012) U and Pb variability in older speleothems and strategies for their chronology. Quaternary Geochronology 14, 105-113.