See Also...206 210 ISOM Index Rock and boulders index previous next
revision 05/00
208 Boulder field
An area which is covered with so many blocks of stone that they cannot be marked individually is shown with ramdomly oriented solid triangles with sides of ratio 8:6:5. A minimum of two triangles should be used. The going is indicated by the density of the triangles. To be able to show the distinction between boulder fields with a significant difference in boulder size it is permitted to enlarge the triangles by 20%.
Colour: black.
Triangle sizes, mixed from 0.5mm - 1.0mm longest size.
An area which is covered with so many blocks of stone that they cannot be marked individually is shown with solid non-equilateral triangles. A minimum of two triangles should be used (one only if used with other rock features). The going is indicated by the density of the triangles.
Defined as point symbols 208.0 & 208.1, can be drawn with any drawing tool. 208.0 has a maximum size of 0.6mm, and 208.1 is 0.5mm.
These are usually sufficient to produce a good looking boulder field. Should you require a more random effect define further symbols.
either:-
Boulder Field: An area covered by many boulders, not individually mapped.
or Group of Boulders: A small boulder field or cluster of boulders.
1) Define a slightly larger symbol (choose 208.0 and select symbol | enlarge/reduce factor 125.00% making sure that the all symbols box does NOT have an X in the check box).
If you wish you may want to do this as a duplicate to gain a further symbol.
2) 1:10000 maps with large boulder fields need small triangles to balance the symbol.
3) Drag the symbol as you draw to create triangles in differing directions.
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