The Maracanã Coastal Plain is located in the northeastern part of the Para State where there are some coastal rias. This place is over tertiary sediments of the Barreiras and Pirabas Formations as well as is over quaternary sediments of the Pos-Barreiras. The Maracana Coastal Plain is influenced by an macrotidal regime (amplitude > 4 m). The Maracana Coastal Plain is characterized by three different geomorphologic domains: (1) Coastal Upland that presents active and inactive cliffs, and platforms of abrasion build in the laterites of Barreiras Formation as well as outcrop of the limestone from Pirabas Formation; (2) Coastal Plain that presents coastal dune fields and palaedunes, beach, mud-tide flat (mangrove), sandy plain, edd-tide delta, beach ridge plain and lakes; (3) Estuarine Plain which presents estuarine funnel, tidal channel and floodflat. In the Maracana Coastal Plain were identified nine morfostratigraphic units: (1) mud-tidal flat, (2) point bar, (3) Sandy plain, (4) dune, (5) paleodune, (6) beach, (7) ebbtide delta, (8) beach ridge plain, and (9) lake. These morfostratigraphic units are associated to three stratigraphic facies: (1) sand facies and point bar mud facies (sandy and muddy) that show alternate layers of greenish gray mud and light gray sand; (2) sea sand facies located over infratide mangrove that it has light olive gray and yellowish gray sands; (3) estuarine mud-sand facies that mean a variable thicking alternate layers with dark gray mud or greenish gray mud. In the Maracana Coastal Plain were characterized three depositional sequences: (1) Basal Transgressive Marine Succession S1, (2) Regressive Marine Succession S2 and (3) Transgressive Marine Succession S3. S1 show mid-large sand in its base (tidal channel) so that following by dark mud with high concentrations of organic matter (sand-silty clay). In these base, the sand is in moderate selection, but to top the sand is fine to middle size and it’s negative asymmetry. Distribution of the mineral clay was homogeneous (kaolinite = 45 %, ilite = 37 % and smectite = 18 %). Heavy minerals show larger concentration in the sandy facies, but the relative amount these minerals increased upward which owing zircon (35 %), staurolite (28 %), epidote (9 %) and cianita (11 %) presences. This sequence of sediments marks an estuarine mud, sea sand and seamud depositions during marine transgressive period. S2 is constituted by thin-very thin, well selected, near asymmetric sand that could be classified as clay-sand sediment. The mineral clay is represented by slight increase of the smectite as well as a decrease of the kaolinite in top sequence. The main heavy mineral located in the point bar are staurolite (44 %), zircon (39 %) and tourmaline (9 %) while there are zircon (39 %) and staurolite (27 %) contents at bottom sequence. This sequence was build during a marine regressive period from coastal upland so that consist the progradational deposits over sequence S1. The sequence S3 corresponds to unit of dunes, barrier-arrow beach, sandy and muddy bars. Coastal dune deposits show some crossing stratification to slow slope and thin layer of mud. Beach deposits show crossing stratus in low angle. Sandy bars presents a full structure with some bioturbation. The contents of sand are well selected and it has quartz as main mineral. The amount of heavy mineral was lower at top layer. Composition and texture of heavy mineral provide a rounding shape of the sediments because it has been transported, reworked and it was suffering a strong abrasion. In the Maracana Coastal Plain, grain size and mineral distribution are homogeneous being not possible to determine a clear edge between stratigraphic sequences either continental contribution or sea sediment source. There are so many morphologic features (cheniers, paleochannel, paleodelta) and some stratigraphic characteristics that suggest an occurrence of sea level oscillations as well as a migration in the shoreline position. The presence of transition environment deposits (tide flat) show some stratigraphic evidence in the study area. The Maracana Coastal Plain and the northeastern coastal area of the Para State (Bragança, Salinopolis and Marapanim) are over actual transgression event (large sandy plain and beach presences).
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