SciELO - Scientific Electronic Library Online

 
vol.48 número1Origen y distribución de depósitos de tsunami en la marisma de Chaihuín (40° S/73,5° O), Chile índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Revista

Articulo

Indicadores

Links relacionados

  • En proceso de indezaciónCitado por Google
  • No hay articulos similaresSimilares en SciELO
  • En proceso de indezaciónSimilares en Google

Compartir


Andean geology

versión On-line ISSN 0718-7106

Resumen

VILLARROEL, Matías; JARA, Pamela  y  CHARRIER, Reynaldo. Role of cohesive discordant bodies on fault-and-thrust belts deformation pattern: an approach based on analogue modelling. AndGeo [online]. 2021, vol.48, n.1, pp.153-174. ISSN 0718-7106.  http://dx.doi.org/10.5027/andgeov48n1-3280.

Lithological heterogeneities in a rock series deformed by the development of a fold-and-thrust belt (FTB) affects the pattern of the resulting structures. We present a series of analogue experiments to determine the effect caused on the deformation pattern of a FTB by the presence of cohesive bodies, like plutons or basement blocks that oppose greater resistance than the host rocks to contractional deformation. The influence of these bodies on the deformation pattern of the FTB was studied by incorporating discordant bodies with different cohesions within a stratified granular sequence with negligible cohesion. We describe two sets of experiments in which the inserted body presents low (Co1) and high (Co2) cohesion respectively. The experiments show a tendency of the structural pattern to curve around the inserted body and to migrate towards the deformation front or the foreland, even when the cohesive body is not exposed. In the first case (Co1) the thrusts cut across the cohesive body, while in the second one (Co2) the cohesive body is not faulted, but transferred towards the deformation front along a basal detachment. Comparison of these results with natural examples at different scales shows a high degree of coincidence in the structural patterns recognized in both cases. Two of the main characteristics of these patterns are the tendency of the thrust faults traces to avoid the cohesive body and adopt the geometry of its distal edge. In order to explain curvatures in natural structural patterns in fold-and-thrust belts, we suggest consider the presence of unexposed bodies with higher strength than their environment.

Palabras clave : Analogue model; Fold-and-thrust belt; Cohesive bodies; Cohesive blocks in FTB.

        · resumen en Español     · texto en Español     · Español ( pdf )