Type Stratigraphic group Country Chile Named for Lebu, Chile Underlies Ranquil Formation | Other Coal Region Bío Bío Region Overlies Quiriquina Formation | |
Sub-units Millongue Formation
Trihueco Formation
Boca Lebu Formation
Curanilahue Formation Primary Slate, Sandstone, Siltstone, Mudstone | ||
Lebu Group is stratigraphic unit of Arauco Basin in south-central Chile. The group consists of a sequence of four formations, of both marine and nonmarine origin, deposited between the Early Paleocene and Middle Eocene.
The group is made up of four formations, from youngers to oldest these are: Millongue Formation, Trihueco Formation, Boca Lebu Formation and Curanilahue Formation.
Eocene Millongue Formation is made up of shale and siltstone of both marine and continental deposition. Its topis made up of an unconformity, the so-called “main unconformity” of Arauco Basin, which is thought to have formed by erosion during a period of tectonic inversion.
References
Lebu Group Wikipedia(Text) CC BY-SA