Geomorphologic analysis of some Martian surface images from the Mars 4 and 5 automatic stations

The paper deals with the results of geomorphological analysis of some photographs taken by the Mars 4 and 5 probes. The area studied (700 × 900 km, centered at 32°S, 35°W) covers part of Mare Erythraeum. The main landforms of the area are craters which are sorted into four morphological classes. Fluvial, eolian, and tectonic processes as well as downslope displacement of material are identified with different degrees of certainty.The valleys, which are probably of fluvial origin, exhibit a characteristic hierarchical pattern. The main valley in the area, provisionally named Uzboi, extends from Holden crater to Hale crater. The relations between the present surface elevations and the probable fluvial origin appear to indicate tectonic uplift of some parts of the area in the past. The tectonic movements have broken a hypothetical large valley into a number of fragments, one of which is Ladon valley and another of which is Uzboi valley, although another possible explanation of the observed pattern also exists. An attempt is made to divide the geologic history of the area into stages. The probable fluvial processes seem to have started before the end of the intensive impact cratetring stage. They appear to have continued, though not so intensely, almost to the recent stage. A geomorphological map of the area shownin Fig. 3.