Experimental models of 'Basement'-controlled salients - application to the proterozoic fold-thrust belt of the quadrilátero ferrífero (Minas Gerais, Southeastern Brazil)

Anais da Academia Brasileira de Ciências

Caroline J. S. Gomes¹  Milton Pereira-filho¹  Silvia C. M. Braga¹ 

[1] ,Universidade Federal de Ouro Preto Departamento GeologiaMG ,Brasil

关键词: experimental modelling;    salients;    brittle deformation;    ductile deformation;    Quadrilátero Ferrífero;    modelagem física;    saliências;    deformação rúptil;    deformação dúctil;    Quadrilátero Ferrífero;   

DOI  :  10.1590/S0001-37652003000200010

来源: SciELO

【 摘 要 】

Scaled sandbox models are used to simulate the development of ´basement´-controlled, salients. We investigate the controlling factors on the development of closed curvatures in map-view, considering constant both the sand pack thickness and the space between obstacles. These models are compared with the Fundão-Cambotas Fault System in the Proterozoic fold-thrust belt in the Quadrilátero Ferrífero region, along the southeastern margin of the São Francisco craton. In the experiments, a pronounced curvature resulted from the margin-controlled salient process in the presence (i) of a basal ductile detachment, or (ii) of pre-existing structures. The results suggest that the convex-to-the-foreland, west-vergent Fundão-Cambotas Fault System that borders the Archean basement highs and displaced older Transamazonian structures westward, is partly a consequence of interaction of propagating thrusts with obstacles in the foreland.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License