Strontium isotope measurements in Greenland ice from the last glacial maximum to the early Holocene

Strontium isotopic composition and concentration have been measured by thermal ionisation mass spectrometry on a suite of samples from the GRIP ice core drilled at Summit, Greenland. The sample ages range from ~24 to ~7.3 ky BP extending from the last glacial maximum into the early Holocene. Less than 10 g of sample was used for each analysis. No attempt was made to separate soluble/insoluble species in the samples. Sr concentrations are between ~950 and ~1,550 pg.g$^{-1}$ over the period ~24 ky to ~14 ky BP but fall dramatically to generally less than 150 pg.g$^{-1}$ between ~14 to ~7.3 ky BP. The $^{87}$Sr/$^{86}$Sr ratio shows a general rising trend from ~0.712 to ~0.715 over the entire period however there are a number of significant deviations from this trend which are most likely due to changing source regions for aerosol dust input to Greenland. Sr isotopic composition shows a strong correlation with $\delta^{80}$O suggesting that climate plays a strong role in determining regions for dust release