[mkgmap-dev] Question about high density Contour Lines

Hello Is there a limit of minimum Contour-Line spacing ? Because my own created Contour-Lines look a little squared and overlap each other. I use Global-Mapper to export Contour-Lines as a .osm File. So mkgmap should be able to convert the Contour-Lines into a Garmin Map. Can anyone tell me how to create ContourLines with a spacing of 1m or 50cm as a separate Map? glg Markus