Loreto Formation

Loreto Formation (Formación Loreto) is a sedimentary formation of Late Eocene age in the southernmost Magallanes Basin. It overlies the Leña Dura Formation and the contact with an overlying formation is not observed. From 2013 to 2020 its coals were mined in Invierno mine, Riesco Island.

Description
The formation contains fossil wood, leaf imprints and palynomorphs. Also fossil fish of Striatolamia macrota and Ischyodus dolloi and indeterminate Spheniscidae fossils have been found in the formation.

The formation crops out in Brunswick Peninsula and Sierra Baguales among other places.