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We present Pb-isotope composition of parent granite and 25 samples of low-temperature mineral assemblages filling open fractures in a granite from southern part of the Melechov Massif of the Moldanubian Batholith, sampled over the 100 m deep borehole PDM-1. The fillings have usually higher U/Pb and 206Pb/207Pb ratios compared to the host granite, which mostly enables dating by one-stage model (i.e., determination of time when their isotopic composition was within the range of the host rock). The most abundant group (12 samples) yielded maximum model ages between 150 and 225 Ma, while their minimum model ages range from 0 to 145 Ma. Variscan ages of up to 300 Ma are probable in the case of 4 samples. Three samples with the highest U/Pb ratios yielded Tertiary model ages (maximum 30-60 Ma); two of them are chemically very contrasting (mainly rich in Mn oxides). It follows that joints could experience several events of uranium and/or lead redistribution throughout their late-Variscan and post-Variscan evolution, with little importance of Quaternary processes. [ABSTRACT FROM AUTHOR]