Odd line of black tiles, default Airport EGBG (Leicester)

Started to look at modifying my local airport (EGBG) witth the Scenery Editor, however I have found there seems to be some odd black tiles, all running in a line thru a central part of the airport, that don’t seem to respond to an ExclusionRectangle or Polygon:



Up close they seem to have a glassy / shiny appearance.

Anyone seen anything like this, know what they are or know how to delete or deal with?

Cheers.

Some extra data: They seem to “modifiy” the terrain mesh, as in the editor they appear to be protruding from the ground by a couple of inches, however once in the simulator there is extra terrain mesh not rendered in the editor above them in places, where this occurs the tiles are “sunk” into the ground, rather than protruding, leaving an equally sized square depression where the ‘tile’ is.

Vennt.