High-precision ages on altered basalts

In addition, analytical techniques involving acid clean-up have been developed to analyse extremely difficult samples from the sea floor (Pringle et al. 1991). 

Another growing field of work has been dating detrital minerals in sediments as a provenance tool, but also in order to study the sedimentary systems supplying basins and uplift or thermal history of the source. Clauer (1981) and Adams and Kelley (1998) have shown that while biotite is often quickly altered in the sedimentary environment, white micas survive and retain ages even in second cycle sediments (those which were originally deposited and then re-excavated during later basin inversions e.g., Sherlock 

K-feldspar also retains pre-erosion cooling ages (e.g., Copeland et al. 1990) but the lower closure temperatures mean that it has more commonly been used for thermal analysis of sedimentary basins (e.g., Harrison and Be 1983). 

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