%0 Journal Article
%T Tectonics and paleogeography of the Maraj車 Basin, northern Brazil
%A COSTA JOˋO B. S.
%A HASUI YOCITERU
%A BEMERGUY RUTH L.
%A SOARES-J迆NIOR ADILSON V.
%J Anais da Academia Brasileira de Ci那ncias
%D 2002
%I Academia Brasileira de Ci那ncias
%X The Maraj車 Basin area presents geologic and geomorphologic features chiefly due to the Mesozoic extension and post-Miocene neotectonics. The extension event with an Early and a Late Cretaceous phases originated four sub-basins that constitutes the Maraj車 Basin, with a thick continental clastic sequence showing marine influence. NW and NNW normal faults and NE and ENE strike-slip faults controlled the basin geometry. The extension, related to the Equatorial Atlantic opening, propagated into the continent along crustal weakness zones of the Precambrian Tumucumaque, Amap芍 and Araguaia orogenic belts. The neotectonic event is a strike-slip regime which developed transtensional basins filled in by Upper Tertiary shallow marine (Pirabas Formation) and transitional sequences (Barreiras Group), followed by Quaternary fluvial deposits and transitional sequences derived from the Amazon and Tocantins rivers and the Marajoara estuary. The current landscape has a typical estuarine morphology. The coast morphology presents sea-cliffs on transitional Upper Tertiary sequences, while inwards dominate hills sustained by Mid-Pleistocene lateritic crust, with a flat erosive surface at 70 m. In the eastern Maraj車 Island several generations of paleochannels associated with fluvial-estuarine sequences are recognized, while a fluvial-marine plain is widespread on its western side.
%K Maraj車 Basin
%K structure
%K evolution
%K paleogeography
%K geomorphology
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652002000300013