The proposal of using the Calabrian Stage to indicate the Lower Pleistocene has been accepted by international community of Quaternary scientists: the base of this stage is coincident with the GSSP in the Vrica section in Calabria, almost coincident with the top of Olduvai paleomagnetic event at 1.81 M.y. B.P. The top of the Calabrian Stage is conventionally located at the Matuyama-Brunhes magnetic reversal, whose age is 0.78 M.y. B.P.
The stratigraphic interval of the Calabrian is almost fully exposed in several stratigrahic sections outcropping in Southern Italy: in particular Calabria and Sicily land sections show the lowest portion of the stage, including the GSSP; the youngest part of the Calabrian succession is well represented in two stratigraphic sections in Crotone area and in the Southern Apennine Foredeep (Lucania Basin).
The same stratigraphic interval has been drilled in several ODP Sites in Southern Thyrrenian and Jonian seas.