Siliceous sinter deposits deriving from hydrothermal activity during the Quaternary are found at various elevations on dormant volcanic centres in the northern Kenya Rift Valley, East Africa. These sinters have been dated by U-series methods, giving ages from 7ka to over 500ka BP (Sturchio et al, 1993). Given various assumptions, the δ18O-SiO2 compositions of the sinters can be converted back to δ18O-H2O values to compare with lakewater compositions inferred from stromatolites. The data suggest that sinters can assist in constraining palaeo-hydrological reconstructions for the late Quaternary in the East African Rift Valley region, particularly during the cooler episodes. Whether sinters can be used in this way further back in the geological record is still under debate.
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