Figure 130

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The Davy crater chain (arrow) is one of the most spectacular chains of craters on the Moon. It extends for about 50 km across the floor of the large, very old crater Davy Y (Y) and onto its eastern rim. The chain may be related in origin to the pair of irregular craters Davy G (G) and Davy GA (GA), 75 km from the furthest end of the chain. Two origins have been proposed. Some lunar geologists believe it is a chain of secondary impact craters, and others believe it is a line of volcanic craters. The simple geometry of the Davy chain, the symmetry and uniform spacing of its individual craters, and its alinement with Davy G strongly support, in this writer's opinion, a volcanic origin. Also arguing against a secondary impact origin is the fact that the Davy chain is a lone feature. There are no other similar chains with this trend in the area. As was shown earlier in this chapter (figs.  124and  125), secondary crater chains tend to occur in large numbers within the belt of secondary craters surrounding a large primary crater.

On Earth some rocks from deep within the crust have been brought to the surface through volcanic orifices, thus providing a means of studying material that would otherwise be inaccessible. For this reason the Davy area was once seriously considered as a landing site. However, when the originally planned number of Apollo missions was reduced, the Davy area was one of those eliminated.  -H.M.

 Colored geologic map of Davy chain (Figure 131)

Report Source: NASA SP-362, Page 133, Figure 130

This web page was created by Francis Ridge for The Lunascan Project
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