Fault-slip, bed-length and area variations in experimental rollover anticlines over listric normal faults: influence in extension and depth to detachment estimations

摘要

To check the behaviour of physical experiments of simple rollover anticlines over listric normal faults, several fault-slip, bed-length and area parameters are measured for different beds in two stages of evolution of two physical experiments. Given a certain amount of extension, the heave and dip of the displacement vary for different beds, whereas the throw is approximately constant for small amounts of extension and the displacement remains constant for high amounts of extension. Neither bed lengths nor areas beneath beds remain constant with increasing extension. A number of techniques allow amounts of extension and detachment depth to be estimated given one or more marker horizons, the portion of the fault between hanging-wall and footwall cut off points, the depth to detachment and/or the shear angle. These techniques are applied to the physical experiments of listric normal faults analysed. Since many of these techniques rely on parameters measured on the physical experiments such as fault slip, bed length and area, the influence of these parameters on the different magnitudes of extension and detachment depths estimated using different techniques is discussed and the accuracy of the results is compared. (C) 2004 Elsevier B.V. All rights reserved.