Positive inversion of extensional footwalls in the southern Serra do Espinhaço, Brazil - insights from sandbox laboratory experiments

Anais da Academia Brasileira de Ciências

Caroline J.s. Gomes²  Marcelo A. Martins-neto²  Valéria E. Ribeiro¹ 

[1] ,Universidade Federal de Ouro Preto Escola de Minas Departamento de GeologiaOuro Preto MG ,Brasil

关键词: experimental modeling;    inversion tectonics;    footwall block;    Espinhaço Basin;    different detachment levels;    modelagem experimental;    inversão tectônica;    bloco do muro;    Bacia Espinhaço;    descolamentos em cotas diferentes;   

DOI  :  10.1590/S0001-37652006000200012

来源: SciELO

【 摘 要 】

Analogue experiments were carried out to get insights into the processes governing positive inversion during the foreland propagating thrust tectonics in the southern Serra do Espinhaço, a Brasiliano/Panafrican foldthrust belt in southeast Brazil. In particular, model listric half-grabens were inverted by applying contractional displacement to the footwall blocks. We investigated two different inversion conditions in listric half-grabens: (i) extensional and contractional detachments at the same level and (ii) at different positions. The models revealed that the development of a forward-breaking thrust system occurs in the basin synrift deposits, by contractional translation of the extensional footwall block when the extensional and contractional master faults do not coincide. Our experiments show the tectonic imbrication between basement and synrift sequences which characterizes the southern Serra do Espinhaço, and support the location in the eastern mountain range domain of the Espinhaço rift master fault system, which is not exposed at the surface.

【 授权许可】

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