Purging and sealing the dead creatures that could cause disease!
December 8th, 2016 http://mars.jpl.nasa.gov/msl-raw-images/msss/01275/mcam/1275MR0059760530604129E01_DXXX.jpg
Please notice how the three dimensional white lines go from way back in the photo and towards the boat that looks like a container (larger area). I truly think it is the martians way in extreme antiquity to get the diseased filled creatures sealed up and cemented, so they would not spead terrible bacteria and diseases. So many thousands of Curiosity photos seem to be truly memorials from martians in homage to their beloved creatures that lost their lives when mars lost it's atmosphere and their planet destroyed in extreme antiquity! Curiousity truly seems to have been ALLOWED (with the consent of the living martians (leaders) to be present on their planet !
Hint: You couldn't have all these story-sculptures that are so tiny and detailed and have them existing today, if their wasn't a civilization at this time living, and in my opinion primarily dwelling under the surface of mars. Too much evidence is forming for this not to be! Basically they are telling the many problems they (the martians) ran into in trying to deal with the MASS creature deaths! It must of been countless and dealing with just the diseases that all those billions of deaths caused is just impossible to comprehend !