Intersection of a DEM and a plane to extrapolate a geological fault

Question

Hello everyone,
I am currently doing a geological map and, based on my field collected fault orientations data points, I would like to infer the extension of the fault in other directions. Said in other words, I would like to create a plane of a certain orientation and being able to extract (i.e. create a feature) the intersecting line with the DEM. 
So, I guess, the first step may be, creating the (fault) plane, then position it where my data point was collected, and finally somehow extract the intersecting line.
Could someone give me a hint? I know many geologist are using ArcGIS so I imagine other people may have faced the same problem.
Until now, I have being doing that manually, with classical mapping technics (i.e. triangulation), but I have recently started using ArcGIS, and I am sure there is a less time consuming way to do it.
Thank you in advance for your help and time,
Lucas

NigelBaker · Answer

i have the same issue.

also a geologist and looking to find the intersection of a 3d plane (bedding plane with known dip/strike) with a 3d surface.

why is there no tool for this? it seems like a common geologist problem to extrapolate the expected outcrop of a particular unit?

i can make a 3d polygon, or multipatch polygon from a known outcrop trace.

i have a 3d raster dem, also TIN surface.

i cannot find a tool within ArcPro that can interpolate the intersection betweeen the 2 features.

lucasMesalles · Answer

Thanks Jeff, I'm trying to explore this tools and see what comes out. 
Just to clarify what my aim is: extract the surface trace of a geological fault from the intersection of a plane and topography.

JeffreySwain · Answer

Based on your description there are two tools that come to mind.  The Intersect 3d tool and the Intersect 3d Line with Multipatch.  I am not sure if that will create what you are looking for, but it may get you started.

You can create a multipatch of your surface with the Interpolate Polygon to Multipatch tool.