Wiktionary
fault trace
n. (context geology English) A line drawn on a map to represent the position of a fault line.
Wikipedia
Fault trace
A fault trace is the intersection of a geological fault with the ground surface, leaving a visible mark. The term also applies to a line plotted on a geological map to represent a fault.
Usage examples of "fault trace".
There was the fault trace of puzzlement dawning in his blank face.