Which Formed First?

Today's VIS image shows an unnamed channel in northern Terra Cimmeria. Two impact craters occur along the length of the channel. The crater rims are higher than the channel floor and are not breached. This observation means the craters are "on top" of the channel, and therefore are younger than the channel. Figuring out which feature formed first is called relative dating. We don't know the absolute ages of either the channel or the impact craters, or how much time elapsed between the channel being carved and the impacts that resulted in the craters. All we can say is what feature formed first. Orbit Number: 78398 Latitude: -2.18803 Longitude: 123.026 Instrument: VIS Captured: 2019-08-17 14:31 https://photojournal.jpl.nasa.gov/catalog/PIA23480