Lutetian

The Lutetian is a stage of the middle Eocene epoch in the international geologic timescale. It is part of the standard framework used to subdivide the Eocene and is named after Lutetia, the Roman name for Paris, in reference to the extensive Lutetian-age deposits found in the Paris Basin. The interval spans roughly 47.8 to 41.2 million years ago, though exact boundary definitions can vary slightly among different stratigraphic schemes. The Lutetian follows the Ypresian stage and is followed by the Bartonian.

In stratigraphic practice, the lower boundary of the Lutetian is defined by a Global Boundary Stratotype Section and Point (GSSP) at a designated section, with the upper boundary likewise marked by a GSSP. These boundaries provide a precise reference for correlating Lutetian rocks worldwide.

Lutetian rocks are widespread in Europe, with particularly well-studied sequences in the Paris Basin. They commonly comprise marine limestones, marls, and associated sediments deposited during warm, shallow seas, along with distal continental facies in some regions. Fossil assemblages include marine invertebrates and vertebrates, as well as plant remains, which aid biostratigraphic correlations across Europe and beyond.

Paleoclimatically, the Lutetian was characterized by relatively warm conditions and high global sea levels, supporting extensive shallow-marine environments. The stage records important facies changes and faunal diversification that accompanied mid-Eocene climatic patterns, contributing to regional sedimentation trends that continued into the Bartonian. The Lutetian thus represents a key interval for studying European stratigraphy and middle Eocene paleoenvironments.