How to Model
Coupled Fault Growth and Associated Sedimentation
Rudkiewicz, Jean-Luc1,
Didier Granjeon1, Marie-Christine Cacas2, Emily Albouy3
(1) IFP, 92852 Rueil
Numerous techniques exist to describe the
kinematic of fault growth, when large scale
horizontal deformation occurs. Fault bent fold or flexural slip are some of the
most commons. Stratigraphic modelling,
aimed at represent the sediment transport, is generally based upon the transport
of sediments into an available accomodation space, as
reconstructed with vertical backstripping.
This paper presents a method to link both
fault growth with large offset and syntectonic
sedimentation, combining the advantages of two methods. The method is based on
the successive modelling of deformation and
sedimentation. The basic idea is to couple sedimentation and deformation only
at specific steps in the basin history. Therefore, the basin is described by a
set of forward structural modelling snap shots,
creating topographic surfaces that are not at depositional equilibrium.
Subsequent sediment erosion and deposition will bring back the basin to
equilibrium if no further horizontal deformation occurs, or will generate
sedimentary wedges that might be involved in further deformation. Hence the
interplay between rate of sediment transport and rate of deformation can be
investigated.
The coupling between deformation and
sedimentation is based upon a down-scaling, upscaling
approach that will be illustrated with simple geologic configurations. This
coupled modelling can be used for example to predict
the occurrence of clastic erosional
facies in a thrustbelt,
resulting from a given history of deformation. Inversely, it can also help to
describe the kinematic of fault movement, as recorded
in the syntectonic sequence.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California