And thank you for your reply Winston.
Actually what firstly puzzled me was this other "fissure":
Which appears to be starting just right off that ridge (whose elevation peaks at 6 to 9 km according to the legend, which is astounding).
I don't want to make science fiction, but to my (untrained) eye it looks just like it would if some kind of "blow" occurred on that mountain's side and ejected material in a straight line outwardly, for several (thousands of?) miles. The line widens and its "bed" gets thinner as it goes on (provided what we see after that horn-like depression is the same line), to only eventually confuse itself with another group of linear surface features (whose nature I'd be at a loss to explain, equally).
But then again, why would a fissure be interrupting at some point, only to "recover" some miles further with a different structure?
Was it a liquid that caused it? I cannot figure out the depth of these holes. The first part of the line seems deep though.
Perhaps I'm seeing exceptionality where there really isn't one. Excuse me if that's the case. I just looked at (possibly trivial) geological features with an inquisitive eye.
It may be if I were glancing comparable maps of the Earth I'd be equally puzzled by our planet's geology (hence my ignorance).