ArcGIS Pro and ArcMap are great for mapping geomorphology. This tutorial shows you how to create polyline features, map and edit those line features and then use the tool 'feature to polygon' to create mapping polygons that you can then attribute and display with mapping classes. Note, that the tool failed in ArcGIS Pro, if you get this same error, just open your lines in Map and run the tool there. This is a common issue in ArcGIS Pro, not all the toolbox commands have yet been properly translated to the newer software (apparently).