Although a reliable relative chronology, based chiefly on the sequence of pottery types, is rapidly being built up for the Andean area, no method has so far been devised for turning the relative dates into absolute ones. As far as we know at present, no permanent method of dating, comparable to the Maya Long Count or even to the Mexican fifty-two-year cycle, was in use in any part of South America, and no one has yet investigated the possibility of building up a tree-ring sequence, even in the drier regions of Peru. Furthermore, the distances that separate the Andean area from the Maya area have so far prevented any correlation of the early pottery types of the two areas, so that we cannot even estimate the age of Peruvian remains in terms of the insecurely correlated Maya calendar.