tivity on the carmel faul

contribution of 232 Th carried by detrital matter in Denya Cave samples. The carbonate
fraction of the samples most probably carries hydrogenous 232 Th. It is possible that this
hydrogenous 232 Th does not overly contribute to the abundance of 230 Th because it is not
as old as 232 Th carried in clays, and therefore does not affect the age of the sample. Under
this assumption an attempt to find a correction factor for each of the detrital samples was
made, in order to correct their ages to that of the samples, which do not contain a detrital
component. As can be seen in Table 4b, two of the samples yielded the same ages as their
detrital free counterparts when a correction factor of ~0.4 was applied (DN-4 pre top and
DN-14a pre). Sample [DN-4 pre II] did not need a correction factor at all. Sample [DN-
37a post] is much older than its detrital free counterpart and a significant correction was
needed in order for them to be of the same age, yet once a correction factor lower than 0.6
was applied the calculated ages were negative. This might mean that theoretically the
factor should be ~0.4 yet there is no way to validate this assumption. These results
indicate that an age correction is not always necessary, even when 230 Th/ 232 Th ratios in
samples are low. However, a correction cannot be arbitrarily neglected and therefore the
single sample method of dating is not appropriate for speleo-seismites from Denya Cave.
Another approach to establishing the real ages of Denya Cave seismite samples was
the Osmond isochron method modified by Ludwig and Titterington (1994; see below).
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