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This is a reduced version
of part of a geologic map of the Davy area compiled by R. Hereford of the
U.S. Geological Survey. Photogeologic mapping did not provide an unambiguous
answer to the question of the origin of the Davy chain, but did provide
much information on the succession of events that shaped this part of the
Moon's surface. Following the map explanation, the succession is briefly
as follows: (1) An early period of intense cratering during which the large
crater Davy Y was excavated and its rim uplifted. (2) A presumably brief
period during which the Cayley Formation and one other plains unit were
deposited. (The origin of the Cayley as a semifluid cloud of ejecta from
the Imbrium basin was discussed in figs. 46, 54, and 55.) (3) A long period
when scattered medium-sized craters and their deposits were formed. (4)
The formation of the Davy crater chain and the larger, presumably volcanic,
craters Davy G and Davy GA. (5) Finally, mass movement of material on steep
slopes to form relatively fresh slope deposits and sporadic impact by very
small bodies that made craters too small to be shown at the scale of the
map.-G.W.C.
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Line marks axis
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Report Source: NASA SP-362, Page 134, Figure 131
This web page was created by Francis Ridge
for The Lunascan Project
Section
Directory 43
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