Rock Cycle
Another approach to evaluating possible lunar material resources is to compare the rock cycle of the Moon (fig. 3) to that of the Earth
(fig. 4). A rock cycle is a sequence of events leading to the formation, alteration,
destruction, and reformation of rocks as a result of! various physical and chemical
processes. Thus, it is a pictorial way of viewing the different processes that
lead to natural material resources such as ore deposits and of predicting the
types of deposits that result from the various physical and chemical processes.
A comparison of the Moon's rock cycle with the Earth's (shown in figures 3 and
4, respectively) reveals the