U-Th Dating Methodology

U-Th purification: Uranium and thorium are separated from the matrix elements by means of extraction chromatography using Eichrom UTEVA cation exchange resin following the method of Pourmand et al. (2007).

Measurement: U-Th isotope measurements are performed with a Neptune Plus multi-collection inductively coupled plasma mass spectrometer (MC-ICP-MS) along with a comprehensive data reduction and uncertainty propagation algorithm following the methodology in Pourmand et al., 2013.

For more information on the methods, refer to the following sources: 

Pourmand A., Marcantonio F., Bianchi T.S., Canuel E.A.and Waterson E.J. (2007) A 28-ka history of sea surface temperature, primary productivity and planktonic community variability in the western Arabian Sea. Paleoceanography, 22, PA4208.

Pourmand, A.; Tissot, F.L.H.; Arienzo, M. and Sharifi, A., 2013: Introducing a Comprehensive Data Reduction and Uncertainty Propagation Algorithm for U-Th Geochronometry with Extraction Chromatography and Isotope Dilution MC-ICP-MS. Geostandards and Geoanalytical Research, DOI: 10.1111/j.1751-908X.2013.00266.x.

Sevag Mehterian; Ali Pourmand; Arash Sharifi; Hamid A.K. Lahijani; Majid Naderi; Peter K. Swart, 2017: Speleothem Records of Glacial/Interglacial Climate from Iran Forewarn of Future Water Availability in the Interior of the Middle East. Quaternary Science Reviews, 164: 187-198. DOI: 10.1016/j.quascirev.2017.03.028.

Monica M.Arienzo, Peter K.Swart, Ali Pourmand, Kenny Broad, Amy C. Clement, Lisa N Murphy, Hubert B. Vonhof, Brian Kakuk, 2015: Bahamian speleothem reveals temperature decrease associated with Heinrich stadials. Earth and Planetary Science Letters, 430:377–386. DOI: 10.1016/j.epsl.2015.08.035

Monica M.Arienzo, Peter K.Swart, Kenny Broad, Amy C. Clement, Ali Pourmand, Brian Kakuk, 2017: Multi-proxy evidence of millennial climate ariability from multiple Bahamian speleothems. Quaternary Science Reviews, 161:18-29. DOI: 10.1016/j.quascirev.2017.02.004