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Palynological study of Holocene sediments of Bom Jesus core, east margin of the Marajó Island, Pará, Amazonia

The upper portion (1.25 m) of the sediment core Bom Jesus (TBJ), was collected in the field-mangrove limit of Bom Jesus Farm, municipality of Soure, island of Marajó, Pará, Brazil, was studied through pollen analysis high resolution aimed at determining the composition, abundance and diversity of the pollen types bioindicators of changes in the palaeobotany. 16 samples of sedimentary 2cm³ were treated according to standard methodology. Tilia and Tilia Graph software were used for to construct abundance and concentration palinological diagrams. The core base was dated by 14C in 2730 ± 40 years AP. Three palynological zones were identified. The mangrove ecosystem was dominant all sedimentary sequence of the TBJ core and was represented mainly for Rhizophora pollen type, which reaches 88% of the maximum relative abundance. Variations applicant hydrodynamics in the Marajó bay, characterized by short pulses of erosive period, seem to have caused reduction in the dominance of mangroves. The increase in the abundance of types growth bioindicators of field associated with elements of swamp forest and restinga, indicate the migration of the field on the mangrove swamp. The data show correlation with other palynological records of Holocene marine transgression to the north coast in the Upper Amazon Holocene.

palynology; mangrove; coastal plain; Holocene; Amazon


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