Taurus-Littrow: A Geologic Field Site and Lunar Base
Harrison H. Schmitt
Apollo 17's exploration of the Valley of Taurus-Littrow on the Moon, in December 1972, led to a greater understanding of both the evolution of the Moon as a planet and the delineation of potential resources for an Earth Orbital Civilization.
The interpretive evolution of the Moon as a planet can be divided into seven major stages, beginning near the end of the formation of the solar system. These stages and their approximate durations in time are as follows: (1) beginning, 4.6 Ga; (2) melted shell, 4.6-4.4 Ga; (3) cratered highlands, 4.4-4.1 Ga; (4) large basins, 4.1-3.9 Ga; (5) light-colored plains, 3.9-3.8 Ga: (6) basaltic maria, 3.8-3.0(?) Ga; and (7) quiet crust, 3.0(?) Ga to present.
The tectonic history of the valley and the surrounding massifs is still puzzling. However, several facts suggest that blocks of the lunar crust may be in continuous, but episodic motion despite the obvious general strength and quiescence of that crust.
Taurus-Littrow is a potential site for a prototype lunar base providing resources to an Earth Orbital Civilization. One of the principal elements contained in lunar materials is oxygen, which is essential to standard chemical space propulsion systems. The probable raw ore for oxygen from the Moon is ilmenite, an oxide of iron and titanium. Ilmenite is present in significant quantities in the already pulverized deep lunar soil (regolith) that overlies titanium-rich mare basalts such as those in the Valley at Taurus-Littrow where Apollo 17 landed. The multistage extraction process that may ultimately be used to produce oxygen from ilmenite also should produce iron, titanium, and hydrogen. Aluminum may be produced for use in manufacturing and as a possible chemical rocket fuel. The main luminum ore on the Moon probably will be the calcium-aluminum silica-rich regolith of the lunar mountains, such as those around the Valley of Taurus-Littrow.
Finally, the demonstrated fertility of the lunar soil may be the basis of an agricultural economy in space, which will support a lunar settlement and Earth-orbit space stations. Once a partly closed ecologic system is established in large lunar facilities, food production can be expanded steadily, and much of the water and nutrients can be recycled.
AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.