An Encyclopaedia of Indian Archaeology v1.c14.s8.t1.1

v1.c14.s8.t1.1

The boundary separating the Pleistocene from the preceding Pliocene is a much debated subject both in India and elsewhere. Recent work on sea sediments has thrown welcome light on this problem and there appears to be a considerable agreement in placing the Plio-Pleistocene boundary at about two million years ago. Ericson and Wollin, 1966, have shown that the boundary is marked by the following: (i) extinction of discosters which had abounded for the preceding 75 million years; (ii) first appearance of *Globoratalia truncatulinoides*; (iii) extinction of *Globigerinoides sacculiferon fistulosa* above the boundary; and (iv) appearance of a uniform lineage of *G. menardii*. Significantly enough, this boundary is also marked by a geomagnetic event, the Olduvai Normal, during the Matuyama Reversed Epoch (Leakey, 1965). Zeuner, 1959, suggested that the appearance of Villefranchian fauna (*Equus*, *Bos* and *Elephas*) and the appearance of the first major glaciation (Alpine Günz) marked the Plio-Pleistocene boundary on land.