Objective:
I need to create a fault with a thickness, or a fault zone in my geological model. It needs to provide an offset (or separation) to other parts of the model.
Resolution:
There are a few different methods of doing this depending on your available input data and the complexity needed.
Fault zones will be represented as volumes in the geological model with one or more faults attached.
Using Distance functions from the fault plane
A fairly simple method to create a set thickness on one or both sides of the fault. Quick to set up and quick to calculate.
Here the buffer output from the distance function will be used as a static mesh (Intrusion from surface) to create the fault zone volume.
Using veins
Works best if the center (reference surface) of the offsetting vein (dyke) is used as the fault. And the boundary (HW/FW) is known of the fault.
Here a vein surface is used to create the fault zone. The surface needs to be built in all the fault blocks that touches the fault surface.
Using Offset erosion surfaces
Useful if there is not a known, or a representative, reference plane to use as the fault. Meaning the FW or HW is used. Here we will create an offset surface from the fault and use to cut out the fault zone.
The fault zone will only appear in one of the fault blocks.
Use a fault both for the FW and the HW
This might be the simplest approach, but you are also creating additional fault blocks that needs to be maintained.
The entire fault block between the faults will be used to classify the volume.
Notes:
- Always test models including faults on a backup or have a backup ready to revert to.
- Faults in Leapfrog are effectively flat 2D planes without thickness.
- You can pick one method or select a range based on what works best for your project.