Photogeology of the multi-ringed crater Haldane in Mare Smythii

Haldane is a 40 km multi-ringed crater that occurs along with similar structures in a belt within the Smythii Basin. It is the best developed structurally of all craters in this belt and displays examples of all materials units of Mare Smythii. In addition to the outer rim, the crater displays a sharp-crested, nearly complete inner ring, and a complex central peak of round hills that are 300-600 m higher than the floor. There are two fracture systems associated with Haldane, one annular and the other radial. The annular fractures seem to control the deposition of mare basalts and dark mantle units in and around the crater. Topographic evidence and flow scarps indicate that the crater was the source of mare basalts and associated dark mantle, rather than its being flooded by such deposits. There are numerous indications that most of the features in and around Haldane are attributable to volcano-tectonic modifications of an original crater-form.