Mississippian - Subdivisions

Subdivisions

In the official geologic timescale, the Mississippian is subdivided into three stages:

• Serpukhovian (330.9 ± 0.2 to 323.2 ± 0.4 mya)
• Visean (346.7 ± 0.4 to 330.9 ± 0.2 mya)
• Tournaisian (358.9 ± 0.4 to 346.7 ± 0.4 mya)

The first two come from European stratigraphy, the last is from Russian stratigraphy. Besides Europe and Russia, there are many local subdivisions that are used as alternatives for the international timescale. In the North American system, the Mississippian is subdivided into four stages:

• Kinderhookian (the lower two-thirds of the Tournaisian)
• Osagean (top of the Tournaisian and bottom of the Visean)
• Meramecian (middle Visean)
• Chesterian (top of the Visean plus the Serpukhovian)