Mapping geological contacts often needs true contact and inferred contact. I would like to know if it is possible to divide a single polygon outline which marks the outline of a granite body, so that it can be inferred contacts (dashed lines) and true contacts (solid lines)? Basically can different borders of a single polygon be edited separately? I am using ArcMap 9.3

  • @Joseph, I am currently using ArcMAP 9.3
    – Marthinus
    Nov 5 '14 at 13:14
  • Have you considered using multiple datasets, one polygon and one line, and using topologies to keep them in sync?
    – Beck
    Nov 5 '14 at 20:13
  • I'm curious about the two answers using lines as the second layer. I realize there's nothing incorrect about this, but why go to the extra step of making it a line layer? I may be missing something, but without even more steps, you'll lose the attributes and I don't see the benefit(s) of lines. But am happy to learn differently. Also, cannot tag both GianlucaF and Beck, so apologize for the lack of recognition.
    – recurvata
    Nov 5 '14 at 23:42
  • @Beck, I think they are suggesting that I use lines in the second layers for the solid contacts that I mapped. I will try this method. Using topologies will it be able to overlay the lines exactly were the polygon boundaries are? They need to overlap exactly. I am new to the topology features
    – Marthinus
    Nov 6 '14 at 7:37
  • I think lines are suggested as the second layer because if you have an attribute in your line feature class to indicate whether it's an inferred or true contact, you can symbolize individual lines separately. You could use the Trace tool to trace lines on your original polygon. A topology can move your lines automatically if you edit the original polygon. If you don't plan on doing this, a topology wouldn't be helpful, but if you do, then it would. Topology is beyond the scope of this question though.
    – recurvata
    Nov 6 '14 at 13:22

In a similar case, I used a linear feature derived from the polygons on the top, and the polygons feature below. Then, you can symbolize your lines accordingly, whereas the polygons borders (the outline color in ArcMap) can be set to no color.


If I understand you correctly, not in any GIS package I'm aware of. The general procedure here would be to use two polygons and symbolize them separately. That said, it is possible to edit edges of a single polygon separately - that is, move, add, delete vertices, etc. - but symbolize then differently, not as far as I know.


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