Tournaisian

Tournaisian
358.9 ± 0.4 – 346.7 ± 0.4 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Paleogeography of the Tournaisian (350 Ma)
Chronology
−360 — – −355 — – −350 — – −345 — – −340 — – −335 — – −330 — – −325 — – −320 — – −315 — – −310 — – −305 — – −300 — – Paleozoic D Carboniferous P Mississippian Pennsylvanian LD Early Middle Late Early Mid Late CS Famennian Tournaisian Viséan Serpukhovian Bashkirian Moscovian Kasimovian Gzhelian Asselian     ← Carboniferous Rainforest Collapse ← Mazon Creek Fossils ← End of Romer's Gap ← Start of Romer's Gap Subdivision of the Carboniferous according to the ICS, as of 2023.[1] Vertical axis scale: Millions of years ago
Etymology
Name formality	Formal
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Age
Stratigraphic unit	Stage
Time span formality	Formal
Lower boundary definition	FAD of the conodont Siphonodella sulcata (discovered to have biostratigraphic issues as of 2006).[2]
Lower boundary GSSP	La Serre, Montagne Noire, France 43°33′20″N 3°21′26″E / 43.5555°N 3.3573°E / 43.5555; 3.3573
Lower GSSP ratified	1990[3]
Upper boundary definition	FAD of the benthic foraminifer Eoparastaffella simplex
Upper boundary GSSP	Pengchong Section, Guangxi, China 24°26′00″N 109°27′00″E / 24.4333°N 109.4500°E / 24.4333; 109.4500
Upper GSSP ratified	2008

The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 358.9 Ma to 346.7 Ma.^[4] It is preceded by the Famennian (the uppermost stage of the Devonian) and is followed by the Viséan. In global stratigraphy, the Tournaisian contains two substages: the Hastarian (lower Tournaisian) and Ivorian (upper Tournaisian). These two substages were originally designated as European regional stages.