CADIC   02618
CENTRO AUSTRAL DE INVESTIGACIONES CIENTIFICAS
Unidad Ejecutora - UE
capítulos de libros
Título:
Progressive deformation of a Coulomb thrust-wedge: the eastern Fuegian Andes Thrust-Fold belt
Autor/es:
PABLO TORRES CARBONELL; LUIS DIMIERI; OLIVERO, EDUARDO B.
Libro:
Kinematic Evolution and Structural Styles of Fold-and-Thrust Belts
Editorial:
The Geological Society of London, Spec. Pub. 349
Referencias:
Año: 2010; p. 123 - 147
Resumen:
Time-calibrated balanced-cross sections of the eastern Fuegian ThrustFold Belt
reveal many complex pro- and retro-vergent structures, rooted at the base of Cretaceous and
within Paleocene rocks. These structures involve the unconformity-bounded syntectonic sequences
of the Austral foreland basin, and accommodate a minimum shortening of c. 41.8 km. The complex
kinematics of the thrustfold belt are recorded by: (1) propagation of the basal de´collement into the
foreland, and forward-directed thrusting during the Ypresian; (2) out-of-sequence thrusting in the
Lutetian; (3) subsidence and sedimentation from the Late Lutetian to the Oligocene; (4) backthrusting
during the Oligocene; and (5) a renewed stage of forward-directed thrusting between the latest
Oligocene and the Early Miocene, probably related to accretion below the sole fault in the hinterland.
This thrust sequence is interpreted as the result of critical Coulomb wedge behaviour during
the first stage of thrustfold belt expansion, with accretion of new material that led to a taper
decrease. The subsequent period of internal deformation corresponds to a subcritical stage,
during which backthrusting accommodates significant shortening (c. 15%). After growth and
taper increase, the last period of forward thrusting at the wedges front marks the inception of a
new critical stage.c. 41.8 km. The complex
kinematics of the thrustfold belt are recorded by: (1) propagation of the basal de´collement into the
foreland, and forward-directed thrusting during the Ypresian; (2) out-of-sequence thrusting in the
Lutetian; (3) subsidence and sedimentation from the Late Lutetian to the Oligocene; (4) backthrusting
during the Oligocene; and (5) a renewed stage of forward-directed thrusting between the latest
Oligocene and the Early Miocene, probably related to accretion below the sole fault in the hinterland.
This thrust sequence is interpreted as the result of critical Coulomb wedge behaviour during
the first stage of thrustfold belt expansion, with accretion of new material that led to a taper
decrease. The subsequent period of internal deformation corresponds to a subcritical stage,
during which backthrusting accommodates significant shortening (c. 15%). After growth and
taper increase, the last period of forward thrusting at the wedges front marks the inception of a
new critical stage.c. 15%). After growth and
taper increase, the last period of forward thrusting at the wedges front marks the inception of a
new critical stage.