Lower Sakamena Gr

Period:

Permian

Age Interval:

Late Permian (Changhsingian)

Province:
Madagascar

Type Locality and Naming

Morondava Basin (and related Sakamena Rift Basin), Madagascar. Named for the Sakamena region in Madagascar. It is the basal division of the Sakamena Group within the Malagasy Karoo-aged rift basins. Included as lower unit in Beaufort Gr in Morondava Basin (Madagascar)

Synonym:

Lithology and Thickness

Composed primarily of a terrestrial clastic sequence consisting of fluvio-lacustrine mudrocks and sandstones.

Lithology Pattern:

Fine-grained sandstone

Relationships and Distribution

Lower contact

Rests upon the older Sakoa Gr.

Upper contact

Overlain by the deltaic and shallow marine strata of the Middle Sakamena Gr. There is debate regarding this contact; some authors (e.g., Wright and Askin, 1987) suggest a continuous transition, while palynological studies (Hankel, 1994) indicate a depositional break or unconformity between the Lower and Middle Sakamena.

Regional extent

Widespread within the Morondava Basin and related rift structures of Madagascar. Beaufort Gr equivalent. It chronostratigraphically correlates with the Late Permian tetrapod-bearing fluvial successions of the Main Karoo Basin in South Africa.

GeoJSON

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Fossils

Age

Late Permian (Changhsingian)

Age Span:

Beginning stage:

Changhsingian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

254.24

Ending stage:

Changhsingian

Fraction up in the ending stage:

1.0

Ending date (Ma):

251.90

Depositional setting

Intracratonic rift basin consisting of terrestrial fluvio-lacustrine (river and lake) environments.

Depositional pattern:

Additional Information

Compiler:

From the O. Catuneanu et al. The Karoo basins of south-central Africa, Journal of African Earth Sciences 43 (2005) 211–253; Smith, R.M.H. (2000): Sedimentology and taphonomy of Late Permian vertebrate fossil localities in southwestern Madagascar. Palaeontologia Africana; Mazin, J.M., & King, G.M. (1991): The first dicynodont from the Late Permian of Malagasy. Palaeontology.