Vertical deformation partitioning across a collapsing large and hot orogen |
| |
| Authors: | F. A. Temporim Ricardo Ivan Ferreirae da Trindade Marcos Egydio-Silva Tiago Valim Angelo Eric Tohver Caroline Cibele Soares Lucas Pequeno Gouvêa Julio Cesar Mendes Silvia Regina Medeiros Antônio Carlos Pedrosa-Soares Gabriel Gomes Silva |
| |
| Affiliation: | 1. Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brazil;2. Instituto de Geociências, Universidade de São Paulo, São Paulo, Brazil;3. Centro de Ciências Exatas, Naturais e da Saúde, Universidade Federal do Espírito Santo, Alegre, Brazil;4. Instituto de Geociências, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;5. Instituto de Geociências, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil |
| |
| Abstract: | Featuring 3 000-km-long large and hot orogen, the Mantiqueira Province provides a rare opportunity to study the process of gravitational collapse at mid to deep crustal levels. Distinct but contemporary (~500 Ma) post-collisional intrusions show structures and anisotropy of magnetic susceptibility (AMS) fabrics related to their emplacements, recording different flow patterns. In southern deep-seated intrusions, ellipsoidal-shaped roots with gabbroic-to-hybrid cores surrounded by granitic rocks show concentric patterns of AMS fabrics that cut across the NE-trending regional foliation. In contrast, northern intrusions, exposed as the upper sections of batholith-size bodies of coarse-grained granite emplaced at the shallow to mid-crust, show general NS-trending magnetic fabrics roughly parallel to strike of the orogen and the regional foliation of host rocks. These contrasting magnetic patterns from shallow to deeper crust suggest vertical magma migration from the overthickened orogenic core to be emplaced across its thinner stretched flanks during the gravitational collapse of the orogenic edifice. |
| |
| Keywords: | |
|
|
