In-plane horizontal stresses acting on predeformed lithosphere induce
differential flexural vertical motions. A high-precision record of these
motions can be found in the sedimentary record of rifted basins.
Originally, it was proposed that rifted basins experience flank uplift
and basin center subsidence in response to a compressive change of
inplane stress, which agrees well with observed differential motions.
Subsequently published models predicted that the vertical motions may be
opposite because of the flexural state of the lithosphere induced by
necking during extension. However, the total, flexural and permanent,
geometry of the lithosphere underlying the rifted basin is the
controlling parameter for the in-plane stress-caused vertical motions.
The largest part of this preexisting geometry is caused by faulting in
the uppermost brittle part of the crust and ductile deformation in the
underlying parts of the lithosphere. We present a new multilayered model
for stress-induced differential subsidence, taking into account the
tectonically induced preexisting geometry of the lithosphere, including
faults in the upper crust. As continental lithosphere may exhibit
flexural decoupling due to a weak lower crustal layer, the new
multilayer in-plane stress model discriminates the geometries of the
separate competent layers. At a basin-wide scale, the new model predicts
that a compressive change of in-plane force results in basin center
subsidence and flank uplift, confirming the original hypothesis.
Compared to all previous models, the new model requires a lower
horizontal stress level change to explain observed differential vertical
motions.