28. Dionysius
(Iron Map)
This map of the iron concentrations of Dionysius shows the marked compositional
contrasts of the crater deposits. The near-rim deposits are low in iron,
confirming their highland affinities. Distal and ray deposits show much
higher iron content, indicating that they are made up of mafic, basaltic
compositions. In addition, the walls of Dionysius show that the crater
formed precisely on top of the mare-highland contact in this region,
with a high-iron eastern wall (right, exposing the basalts of Mare Tranquillitatis)
and a very low iron western wall (left, exposing highlands of the Cayley
plains). The ejecta relations in this crater can be used to reconstruct
the preimpact target stratigraphy in this region of the Moon. Through
this technique, we can probe the composition and structure of the lunar
crust at depth.
