Continental sedimentation of the Las Flores Formation (Early Palaeogene) in Golfo San Jorge basin (Patagonia, Argentina).

RAIGEMBORN, M. S.; KRAUSE, J. M.; MATHEOS S. D.

Alghero (ITALIA)

Congreso; 27th Regional Meeting of the IAS; 2009

IAS

The Late Palaeocene–Lower Eocene sedimentation at north of the Golfo San Jorge basin, Central Patagonia, Argentina, is recorded by the Las Flores Formation. It is a fluvial-lacustrine unit, which spans a time deposition contemporary with part of the Paleogene global warming. Their type section is defined as essentially composed by mudstones. However, the well-exposed outcrop in the southeast of the Chubut province reveals significant sedimentary differences in the unit. Two main areas, eastern and western ones, were defined. The former is composed by 33–52 m thick, white and pink sandstones (lithic feldsarenites), conglomerates and silstones. The western area is 24–44 m thick and mainly consists of grayish siltstones and minor epiclastic and volcaniclastic sandstones. In both areas, kaolinite dominates the clay mineral assemblage.