It is among the very few Paleogene fossil deposits from Southeast Asia that preserves a freshwater ecosystem, and contains many of the earliest records of freshwater fish taxa that now predominate the region.

More recently, unpublished palynological data suggests that the overlying Sawahlunto Formation is of middle-late Eocene in age, which would most likely place the Sangkarewang Formation in the early-mid Eocene.

The Sangkarewang Formation was deposited within a freshwater rift lake that formed in this basin early on, with anoxic bottom waters allowing for the fossilization of the fish skeletons.

During the Oligocene, this gave way to a river delta (the Sawahtambang Formation), and was later flooded by the sea by the Miocene (the Ombilin Formation), before a tectonic uplift raised it above the sea.

[5][6] Sanders (1934) published a comprehensive monograph about the fishes of the formation using a large number of specimens.