Geologic Fold Axes Symbols

DoeDoe Global Mapper UserPosts: 87Trusted User
edited November 2012 in Suggestion Box
From the perspective of a geologist I'd like to have a tool that can draw lines with symbols that indicate the general geometry of fold axes. To a geologist, these symbols and line traces summarize a lot of topographical data into geometric domains. I think most of the tools needed are already functional in GM. The greatest effort is development of a GUI and symbols database (which should be small).

Mike

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited November 2012
    Mike,

    Are there some line styles used for these maps that aren't in Global Mapper currently? Point styles and area styles are easy to add as custom symbols/styles, but line styles are unfortunately much harder.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • energyenergy Global Mapper User Posts: 384Trusted User
    edited November 2012
    I agree with Doe, GM has not developed itself for geology and geolgists, essipecally unit and features symbols.
  • DoeDoe Global Mapper User Posts: 87Trusted User
    edited November 2012
    Hi Mike,

    Could I send you an example map that shows what I mean? It is a little large (188 Mg). The legend at the bottom of the map has the symbols and the map show them in use. I can clarify what each feature means later, as needed.

    Mike
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited November 2012
    Mike,

    You could just send a screen grab of just the legend. I actually think I have some other maps from you. In all likelihood it would be a while before I could get to them as I have to dedicate almost the entirety of the next couple of months at least to new Lidar functionality and I'm already down to no hours in the day other than sleep, eat, and work and even sleep is slowly going away with all of the volume of requests.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • DoeDoe Global Mapper User Posts: 87Trusted User
    edited November 2012
    Mike,

    Hey, don't burn yourself out. Wish I could help. I am looking to re-enter the workforce early next year....

    Here are symbol examples and a map example. The line representing the trace of a fold axis (antiformal or synformal) also reflect the basic geometry of the fold in cross-section. A fold can change in cross-sectional shape along the trace of the axis. The cross-section shape of the fold often reflects critical information about the deformation and general trends of the folded strata. Finally, the line tracing a fold axis may trend up and down. A fold axis can plunge in two directions - think of the hinge line trace as the path of a swimming porpoise as it travels near the surface - going up and down as it rides waves and grabs breaths. This means a fold axis may show arrows at each end or, possibly along the trace in addition to the cross-section representations.

    Let me know if this isn't clear.

    Mike

    Fold axes symbols.jpgMap example.jpg
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited November 2012
    Mike,

    Are these not things that can be modeled with the existing line styles that have arrows at one or both ends? Or would there need to be new line styles where the curved-arrow (i.e. dolphin path) lines are drawn along the actual line path itself rather than those being separate line features?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • DoeDoe Global Mapper User Posts: 87Trusted User
    edited November 2012
    Mike,

    The line that traces the fold axis can, and usually is, a simple line. Arrows at each end are not always required but are used often. Where the fold axis changes from a downward plunge to a climbing plunge would probably, usually is, a good place to break the line. The fold geometry indicator is the problem. The symbol should always be orthogonal to the local trend of the line. I think tying the geometry indicator to a vertice on the axis line would work. I am not sure how to control the orientation computationally but it should remain orthogonal to axis line as well as possible. Perhaps using something like the strike and dip tool to select and spot the geometry indicator would work. Perhaps let the user make the small orientation adjustment. Having an option to simply "flip" or orient the symbols may also be useful. As I said, the fold geometry can frequently change along the axial trace so more than one type of symbol may be assigned to an axial segment. There is no spacing standard for the geometry indicator.

    Mike
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited November 2012
    Mike,

    Would any of the built-in line styles with some type of feature drawn off to the side of the line work? There are a bunch of line styles with things going off to the right of left of the line that are orthogonal to the line, including "rakes" (straight lines off to one side), triangles (arrow), squares, half circles, etc. If you create a new line and specify to use a custom style you can select from the long list of styles to see what is available. Or even better go to http://www.globalmapper.com/helpv14/types_styles/Help_Built-In_Styles.html#drawstyle and you can see examples of all of them.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • DoeDoe Global Mapper User Posts: 87Trusted User
    edited November 2012
    Mike,

    Perhaps. Usually the cross-section geometry indicators are variably spaced, usually sparingly. They are placed where needed without detracting from rest of the data. The ready made line types is along the right line but their spacing may be too redundant. Is it possible to control the number and spacing? Imagine drawing a curving line along a sinuous fold where you may only want one geometry indicator to represent that entire segment. Also, consider the example above where the syncline transitions to another geometry along the trace of a single fold axis. I like what you are thinking but just don't know enough about the tool (like spacing or frequency of the symbols) to make the call.

    Mike
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited November 2012
    Mike,

    There are some different style selections that have wider spaced indicators than others, but there isn't any direct control over the spacing. Are you saying perhaps additional styles where only one instance of the geometry indicator is drawn either for the whole line or perhaps per segment? This could be done probably without too much trouble. Which style indicators in particularly would be most useful to have this for (i.e. triangle, square, rake/straight line, etc.)?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • DoeDoe Global Mapper User Posts: 87Trusted User
    edited November 2012
    Mike,

    I think a single instance geometry indicator would work. I think the symbols that I sent would cover most situations. These are symbols for synclines, antilcines, asymmetric (double arrows on one side) for both anti- and synforms, and the overturned fold indicators. I think the single or double arrow options on the line ends need to remain available. Any change in geometry will represented by a new section of line.

    Mike
Sign In or Register to comment.