Victoria Quadrangle - Crater Distributions

Crater Distributions

Because of the varied and generally poor quality of the imagery, detailed cratering history cannot be inferred from these plots. However, three observations seem valid:

• the density of large craters is distinctly higher for intercrater than for intermediate plains material;
• for the intercrater and intermediate plains material, curves for craters with diameters between 3 and 15 km nearly coincide (the abundant, mostly degraded small craters characteristic of intercrater plains material but not characteristic of intermediate plains material are less than 3 km in diameter);
• craters of all sizes on the smooth plains unit are much less abundant than on the other units, although the smooth-plains plot is unreliable in detail because of the small total number of craters counted and the need to combine counts from isolated exposures.

A serious sampling problem exists for counting craters on the intermediate plains unit, because those in the diameter range of 50 to 150 km commonly occur in clusters, and it is very difficult to determine which craters of a cluster are younger than the surrounding plains unit and which are older.