Mari Mari Group
Stratigraphic range: Eifelian ~392–384 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Late Devonian paleogeography (380 Ma)
Type	Geological group
Lithology
Primary	Shale
Other	Sandstone
Location
Coordinates	6°00′S 70°00′W / 6.0°S 70.0°W / -6.0; -70.0
Approximate paleocoordinates	59°54′S 61°30′W / 59.9°S 61.5°W / -59.9; -61.5
Region	Amazonas
Country	Brazil
Extent	Amazon Basin
Type section
Named for	Marimari River
Mari Mari Group (Brazil)

The Mari Mari Group is an Eifelian to Frasnian geologic group of the Amazon Basin in the state of Amazonas of northwestern Brazil. The group comprises shales and sandstones.^[1]

The formation has provided fossils of Tentaculites sp., foraminifera and ostracods.^[1][2]

• Melo, J. H. G (1988), The Malvinokaffric realm in the Devonian of Brazil. N. J. McMillan, A. F. Embry, and D. J. Glass, eds. Devonian of the World, Volume I, Canadian Society of Petroleum Geologists. Calgary, Alberta, Canada, pp. 669–703