Early Triassic plant microfossils from Sakamena sediments of the Majunga Basin, Madagascar

Abstract

This study deals with plant microfossils from Karoo deposits of northern Madagascar. The microfloral assemblages have been recovered from Sakamena sediments exposed in the northern part of the Majunga Basin (Andreba area). The assemblages are characterized by the association of cavate spores, taeniate pollen and acritarchs including marine phytoplankton. A very close affinity exists with palynofloras from marine Early Triassic strata of the Salt Range of Pakistan. The composition of the present assemblages suggests that the Sakamena section examined is time equivalent with the upper part of the Mittiwali Member of the Mianwali Formation. It is concluded that the Sakamena assemblages are of early Smithian age. There is also a close correspondence with the Early Triassic assemblages of the Kraeuselisporites saeptatus Zone of Western Australia recorded from marine sediments of the Perth Basin (Kockatea Shale) and the Carnarvon Basin (lower part of Locker Shale). Other Gondwana palynofloras which are regarded here as comparable and coeval to the present assemblages all come from continental strata. These are Early Triassic assemblages of eastern Australia ( Protohaploxypinus samoilovichii Zone), India (Purnea microflora), and Kenya (Lower Mariakani assemblages). In southern Madagascar, equivalent assemblages are those from the Upper Sakamena (Zone II B) of the Morondava Basin.