tivity on the carmel faul

generally considered to be associated with a detrital component that becomes cemented, or
occluded within the speleothem. This component may be composed of clays, alumino-silicates
or Fe-oxyhydroxides with strongly absorbed Th 4+ . Th incorporated in speleothems may also
have been transported in colloidal phases, attached to organic molecules or as carbonate
complexes in solution (Richards and Dorale, 2003 and references therein).
The extent of initial Th contamination can be monitored by measurement of 232 Th, which
is the most abundant, extremely long lived isotope of Th with a half life of 1.401x10 10 y. Where
232 Th content is high, initial 230 Th concentration is also expected to be significant. To a first
approximation, correction can be made for the detrital component of 230 Th by using the 232 Th
concentration as an index of contamination and assuming an appropriate value of 230 Th/ 232 Th
for the sedimentary context. By assuming that 232 Th was incorporated at the time of
contamination, and that the excess 230 Th associated with this 232 Th decayed over time since
then, in situ ingrowth within the authigenic carbonate phase can be calculated. The
concentrations of 234 U and 238 U in the authigenic carbonate are assumed to equal their
concentrations in the lechate that includes the portion of detritus that has entered solution
(Richards and Dorale, 2003).
Two methods of age corrections for initial 230 Th have been attempted in this study; (1)
Finding a correction value for the Denya Cave depositional environment. This was initially
attempted by using the isochron method suggested by Kaufman et al. (1998) as was done for
Soreq Cave. Later on a direct approach to finding this correction value was applied. (2) Using
the isochron method based on Osmond type isochrons as suggested by Ludwig and Titterington
(1994), applied using Isoplot3.7 (Ludwig, 2008). Both methods and their consequent results
are further discussed below (ch’s. 3, 4- Methodology and Results).
1.4 Geological setting of Carmel region
Studies based on geophysical evidence suggest the continental margin west of the DST
is divided into two major provinces, the boundary between which is the CF system and its
postulated continuation offshore (Hofstetter et al. 1991; Ben-Avaham and Ginzburg, 1990;
Garfunkel and Almagor, 1985).
The northern CF is part of a fault system that begins at the Beth-Shean area of the DST
and extends into the continental shelf of the eastern Mediterranean (Fig. 2; Schattner et al.,
2006; Ben-Avraham and Hall, 1977). This system is a secondary branching of the DST
(Freund, 1965). Freund et al. (1970) found a connection between the DST and young faulting
trends in Eastern Galilee and in Lebanon, and concluded that this intense faulting trend is
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