Anonymous asked in Science & MathematicsEarth Sciences & Geology · 3 weeks ago

Geology help!?

I have a test a Monday and genuinely don’t understand the maps. This may be a stupid question but when looking at a map... the lines are so small. How do you tell which is plates/ boundaries and if their convergent, divergent or transform?? Thanks!!

4 Answers

  • 3 weeks ago

    Usually convergent boundaries are marked with triangles on the edge of the subducting plate in the direction of its movement. Divergent and transform boundaries are sometimes marked with arrows showing their direction of movement, but more often they are color coded, and you just have to memorize which is which. For reference, compare the San Andreas Fault in California (a transform boundary) to the Mid-Atlantic Ridge (a divergent boundary).

    Source(s): An example of the Sunda Plate boundaries: Blue is convergent subducted, purple is convergent suture (such as the Himalayas), red is divergent and green is transform.
  • 3 weeks ago

    Depends on the map. Different maps show different things. Only thing I will say is that a geologist really does have to be able to read maps. If a map does not expressly show plate boundaries, then you can't really declare a boundary, as the location of a boundary is an interpretation of the geology. Graben structures are a good indication that you are dealing with rifting, but you can get graben structures from tensional tectonics that are not evidence of a divergent plate boundary. Back-arc spreading can produce localized tension away from the plate boundary, for example.

    Usually, the type of faulting is the primary way of identifying the possible existence of a plate boundary. Rifting (divergent boundary) has (mirrored) normal faults, subduction (convergent boundary) has a dominant reverse fault system, and lateral boundaries involve transform faults.

  • 3 weeks ago

    No one can answer your question until they see an image of the map. Can't you zoom in? Any plate boundary with triangles on one side is a convergent boundary. 

    Insufficient information to answer the question. 

    Source(s): B.S. earth sciences / geology, M.S. geology
  • Ron
    Lv 7
    3 weeks ago

    Can I see a map?

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