Geometry and kinematics of experimental antiformal stacks

Anais da Academia Brasileira de Ciências

Caroline Janette Souza Gomes¹  Juliano EfigÊnio Ferreira¹ 

[1] ,Universidade Federal de Ouro Preto Departamento de Geologia Ouro Preto Minas Gerais ,Brasil

关键词: basement structures;    slightly dipping basal detachment;    sand layer thickness;    basal friction;   

DOI  :  10.1590/S0001-37652000000200008

来源: SciELO

【 摘 要 】

Sandbox experiments with different boundary conditions demonstrate that antiformal stacks result from a forward-breaking thrust sequence. An obstacle blocks forward thrust propagation and transfers the deformation back to the hinterland in a previously formed true duplex. In the hinterland, continued shortening causes faults to merge toward the tectonic transport direction until the older thrusts override the younger thrusts. In experiments using thin sand layers or high basal friction, shortening is accommodated by a cyclic process of thrusting, back rotation of the newly formed thrust combined with strong vertical strain, and nucleation of a new thrust. Continuous deformation produces an antiformal stack through progressive convergence of branch lines.

【 授权许可】

CC BY   
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