chatter mark

from WordNet (r) 3.0 (2006)

chatter mark
    n 1: marks on a glaciated rock caused by the movement of a
         glacier
    2: a mark made by a chattering tool on the surface of a
       workpiece

from The Collaborative International Dictionary of English v.0.48

Chatter mark \Chat"ter mark`\
   (a) (Mach.) One of the fine undulations or ripples which are
       formed on the surface of work by a cutting tool which
       chatters.
   (b) (Geol.) A short crack on a rock surface planed smooth by
       a glacier.
       [Webster 1913 Suppl.]