Science. 1972 Feb 18;175(4023):755-7. doi: 10.1126/science.175.4023.755.
Light and dark terrains in and around Meridiani Sinus, mapped on the imagery from Mariner 6 and Mariner 7, were found to have significantly different cumulative size frequency distributions of craters. The light terrain on a mosaic of frames 6N11, 6N13, and 6N19 has a greater proportion of large craters and a lesser proportion of smaller craters than the dark terrain on the same frames. The light terrain is interpreted to be generally older than the dark terrain. The filling or partial filling of the smaller craters on the light terrain by surface detritus is suggested. Several wide-angle frames have remarkably similar cumulative crater size frequency distributions that may be representative of a large portion of the martian surface.
水手 6 号和水手 7 号拍摄的影像显示，子午线高原及其周围的明暗地形的陨石坑累积尺寸频率分布有显著差异。6N11、6N13 和 6N19 拼接图上的亮地形比同一帧上的暗地形有更大比例的大型陨石坑和更小比例的小型陨石坑。亮地形被解释为通常比暗地形更古老。表面碎屑对亮地形上较小陨石坑的填充或部分填充被提出。几个广角图像具有非常相似的累积陨石坑尺寸频率分布，可能代表了火星表面的很大一部分。
