Piacenzian

Formerly part ofTertiaryPeriod/SystemEtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionBase of Gauss/Gilbert (C2An/C2Ar) magnetic reversalLower boundary GSSPPunta Piccola Section, Porto Empedocle, Sicily, Italy
37°17′20″N13°29′36″E / 37.2889°N 13.4933°E / 37.2889; 13.4933Lower GSSP ratifiedJanuary 1997Upper boundary definition

• Base of magnetic polarity chronozone C2r (Matuyama)
• Extinction of the HaptophytesDiscoaster pentaradiatus and Discoaster surculus

Upper boundary GSSPMonte San Nicola Section, Gela, Sicily, Italy
37°08′49″N14°12′13″E / 37.1469°N 14.2035°E / 37.1469; 14.2035Upper GSSP ratified1996 (as base of Gelasian)

The Piacenzian is in the international geologic time scale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.58 Ma (million years ago). The Piacenzian is after the Zanclean and is followed by the Gelasian (part of the Pleistocene).

The Piacenzian is roughly coeval with the European land mammal age MN 16, overlaps the late Chapadmalalan and early UquianSouth American land mammal age and falls inside the more extensive BlancanNorth American land mammal age. It also correlates with the Astian, Redonian, Reuverian and Romanian regional stages of Europe, and the Waipipian and Mangapanian stages of New Zealand. Some authorities describe the British Red Crag Formation and Waltonian Stage as late Piacenzian, while others regard them as early Pleistocene.

Carbon dioxide levels during the Piacenzian were similar to those of today, making this age, with global mean temperature 2–3 °C (3.6–5.4 °F) higher and sea levels about 20 metres (66 feet) higher than today, an important analogue for predictions of the future of our world.