SDEM modelling of fault-propagation folding: a dynamic-kinematicanalysis

TY - ABST

T1 - SDEM modelling of fault-propagation folding

T2 - EGU General Assembly 2009

AU - Clausen, O.R.

AU - Egholm, D.L.

AU - Poulsen, Jane Bang

AU - Refstrup, Lisbeth Hoberg

N1 - Volumne: 11

PY - 2009

Y1 - 2009

N2 - Understanding the dynamics and kinematics of fault-propagation-folding is important for evaluating the associatedhydrocarbon play, for accomplishing reliable section balancing (structural reconstruction), and for assessingseismic hazards. Accordingly, the deformation style of fault-propagation-folding has already been the topic of alarge number of empirical studies as well as physical and computational model experiments.However, with the newly developed Stress-based Discrete Element Method (SDEM), we have, for the firsttime, explored computationally the link between self-emerging fault patterns and variations in Mohr-Coulombparameters including internal friction.Using SDEM modelling, we have mapped the propagation of the tip-line of the fault, as well as the evolutionof the fold geometry across sedimentary layers of contrasting rheological parameters, as a function of theincreased offset on the master fault. The SDEM modelling enables us to evaluate quantitatively the rate of strain. A high strain rate and a step gradient indicate the presence of an active fault, whereas a low strain-rate and lowgradient indicates no or very low deformation intensity. The strain-rate evolution thus gives a precise indication ofwhen faults develop and hence also the sequential evolution of secondary faults.Here we focus on the generation of a fault -propagated fold with a reverse sense of motion at the master fault, andvarying only the dip of the master fault and the mechanical behaviour of the deformed layers overlying the masterfault. The results show that the Mohr-Coulomb parameters of the succession overlying the master fault controlthe overall deformation of the succession, and that the geometry of the faults, and the frequency of secondarystructures, depend on the internal friction of the layers and the dip of the masterfault. The modelled results arefurthermore related to observations on seismics.

AB - Understanding the dynamics and kinematics of fault-propagation-folding is important for evaluating the associatedhydrocarbon play, for accomplishing reliable section balancing (structural reconstruction), and for assessingseismic hazards. Accordingly, the deformation style of fault-propagation-folding has already been the topic of alarge number of empirical studies as well as physical and computational model experiments.However, with the newly developed Stress-based Discrete Element Method (SDEM), we have, for the firsttime, explored computationally the link between self-emerging fault patterns and variations in Mohr-Coulombparameters including internal friction.Using SDEM modelling, we have mapped the propagation of the tip-line of the fault, as well as the evolutionof the fold geometry across sedimentary layers of contrasting rheological parameters, as a function of theincreased offset on the master fault. The SDEM modelling enables us to evaluate quantitatively the rate of strain. A high strain rate and a step gradient indicate the presence of an active fault, whereas a low strain-rate and lowgradient indicates no or very low deformation intensity. The strain-rate evolution thus gives a precise indication ofwhen faults develop and hence also the sequential evolution of secondary faults.Here we focus on the generation of a fault -propagated fold with a reverse sense of motion at the master fault, andvarying only the dip of the master fault and the mechanical behaviour of the deformed layers overlying the masterfault. The results show that the Mohr-Coulomb parameters of the succession overlying the master fault controlthe overall deformation of the succession, and that the geometry of the faults, and the frequency of secondarystructures, depend on the internal friction of the layers and the dip of the masterfault. The modelled results arefurthermore related to observations on seismics.

M3 - Conference abstract in journal

SN - 1607-7962

JO - Geophysical Research Abstracts

JF - Geophysical Research Abstracts

IS - EGU2009-4652

Y2 - 17 December 2010

ER -