1.. The final age in the Pliocene Epoch, preceded by the Zanclian (Tabianian), followed by the Calabrian (Quaternary), and dated at 3.4–1.64 Ma ( Harland et al., 1989).
2.. The name of the corresponding European stage which was originally described as a subdivision of the (then recognized) Astian Stage. It is roughly contemporaneous with the upper Delmontian, Repettian, and Venturan (N. America), Waipipian, Mangapanian, and lowermost Nukumaruan (New Zealand), and upper Kalimnan and Yatalan (Australia). The type area is around Castell' Arquato, Italy.
"Piacenzian." A Dictionary of Earth Sciences. . Encyclopedia.com. (September 21, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/piacenzian
"Piacenzian." A Dictionary of Earth Sciences. . Retrieved September 21, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/piacenzian