Vertical deformation partitioning across a collapsing large and hot orogen

Author(s):Show less -

Temporim, F. A. ; Ferreirae da Trindade, Ricardo Ivan ; Egydio-Silva, Marcos ; Angelo, Tiago Valim ; Tohver, Eric ; Soares, Caroline Cibele ; Gouvea, Lucas Pequeno ; Mendes, Julio Cesar ; Medeiros, Silvia Regina ; Pedrosa-Soares, Antonio Carlos ; Silva, Gabriel Gomes

• Document type: Journal article
• Source: TERRA NOVA; v. 35, n. 1, p. 9-pg., 2022-10-17.

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 (similar to 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. (AU)

• FAPESP's process: 16/06114-6 - The Neoproterozoic Earth System and the rise of biological complexity
• Grantee: Ricardo Ivan Ferreira da Trindade
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/11672-0 - Ediacaran-Cambrian paleogeography study of post-collisional intrusions from Araçuaí belt (es)
• Grantee: Filipe Altoé Temporim
• Support Opportunities: Scholarships in Brazil - Doctorate