Preliminary report on radiocarbon dating of cryptoendolithic microorganisms.

The existence of microbial communities living inside desert rocks has been reported by FRIEDMANN et al. (1967, 1976), first in rocks collected from the hot and dry Negev desert and later in rocks in the frigid Ross Desert of Southern Victoria Land, Antarctica. The extremely inhospitable climatic conditions in both places has led to the suggestion that these organisms have very low rates of metabolism and may, in addition, be very old (FRIEDMANN 1982). Our preliminary measurements showed a 14C deficiency indicating a carbon age in the order of magnitude of 10(3) years.