
EVOLUÇÃO TECTÔNICA DO CRÁTON DO GUAPORÉ: COMPARADA COM A DO ESCUDO BÁLTICO
1974; Sociedade Brasileira de Geologia; Volume: 4; Issue: 3 Linguagem: Inglês
10.5327/rbg.v4i3.62
ISSN2317-4889
AutoresFernando Flávio Marques de Almeida,
Tópico(s)Geochemistry and Geologic Mapping
ResumoA comparative study of the Precambrian tectonic differentiation of the Guapore Craton in South America, and the Baltic Shield in Europe, demonstrate that the major geologic events are synchronous and correlatables. The Transamazonian and Svecofennian-Karelian cycles are equivalent in age and geologic products, as well as the volcanic phenomena Uatuma and sub-Jotnian, which were both accompanied and followed by anorogenic granites between 1,700 and 1,500 m.y. The subsequent clastic Precambrian covers in both cratonic areas are associated with basic magmatism. The eastern part of the Guapore Craton and the southwestern part of the Baltic Shield underwent tectonic regeneration in middle Upper Precambrian, where the Uruacuan and Dalslandian geosynclines were formed. A tectono-magmatic reactivation at about 1,000 m.y., with production of anorogenic granites and acid to intermediate volcanism (Rondonia), as well as the Late Precambrian geosynclinal evolution at the eastern border of the Guapore Craton (Brasiliano) find no counterparts in the Baltic Shield.
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