| Popis: |
Geological history records the occurrence of four supercontinents (Columbia, Rodinia, Panotia/Gondwana and Pangea). Traces of these events are recognized in the Northwest of Ceara through the following episodes: (1) Transamazonian/Atlantida Orogenesis (continental Columbia masses), generating the Granja Complex (2.0 Ga); (2) Columbia division generating klippe (1.7 Ga); (3) rifting of Rodinia (800-750 Ma), with deposition of neoproterozoic supracrustal sequences; (4) agglutination of Panotia/Gondwana (Orogenesis Brasiliana, 665-590 Ma), creating the Brasiliana Chain; (5) collapse of orogens and formation of the Jaibaras and Parnaiba basins, from the division of Panotia (530-515 Ma); (6) deposition of the Serra Grande Group in the Parnaiba Basin (440 Ma), associated with the drift of Gondwana; (7) intracontinental rifting (145-120 Ma) generating uplifting of the Parnaiba Basin and exhumation of granites, followed by the opening of the Atlantic, from the fission of Pangea/Gondwana (120-100 Ma); 8) flexural uplifting of the interior of the continent (from 65 Ma), with exhumation of massifs, crustal reactivation in the Meruoca Massif and circunsdenuation in the Parnaiba Basin, generating the Glint of Ibiapaba. Keywords: supercontinents; plate tectonics; megageomorphology. |
