This image shows the transition from a regular channel to an inverted channel in Arabia Terra. The channel was once flowing with water that carved down into the bedrock to produce a depression. As the water flow slowed down, sediment became deposited within the channel that caused it to partially fill up. Over time, the landscape around the channel eroded away faster than the sediments within the channel, leaving behind a portion that now stands above the terrain, called an inverted channel. Why only one section of the channel is inverted while the rest is still a depression is unclear, but may reflect the local topography and hardness of the neighboring materials that only protected the channel in some places. https://photojournal.jpl.nasa.gov/catalog/PIA25983