Engineering topics

Schaeffer, O. A.

Publications and source records attributed to Schaeffer, O. A..

27 records · Page 2

NASA NTRS1973

Lunar volcanism - Age of the glass in the Apollo 17 orange soil.

Glasses on the moon can form either by impact or by volcanic processes. An age determination indicates that the glass of the orange soil formed close in time to the volcanic activity in the Sea of Serenity about 3,750 million years ago. The orange soil was certainly not formed by a recent fumarole. The young exposure age, about 32 million years, found for the glass of the orange soil is in agreement with its fresh appearance on the lunar surface.

Husain, L.↗

NASA NTRS1973

Early lunar history - Ages of 2 to 4 mm soil fragments from the lunar highlands

The ages of twenty-one 2 to 4 mm soil fragments from Apollo 16 stations 6, 8, 11, and 13, including all six major petrographic rock types found among Apollo 16 samples, were determined using the Ar-40/Ar-39 stepwise-heating technique. Twelve of the twenty-one samples have ages within 3.95 to 4.06 billion years, and it is believed that they represent the age of at least one stage of the Cayley Formation. Four samples have ages distinctly older than 4.00 billion years, making them the oldest lunar material found to date.

Schaeffer, O. A.↗

NASA NTRS1972

Age of a lunar anorthosite.

The crystallization age of an Apollo 15 anorthosite rock, 15415,9, returned from the lunar highlands has been measured to be 4.09 (plus or minus 0.19) b.y. The primitive lunar crust must have been formed in the first 300 to 400 m.y. The results give some credence to the hypothesis that the primitive lunar surface was molten and large-scale fractional crystallization occurred in the early history of the moon.

Husain, L.↗

NASA NTRS1972

The ages of lunar material from Fra Mauro, Hadley Rille, and Spur Crater.

Ar-40/Ar-39 dating techniques were applied to estimate the age of twelve crystalline and fragmented Fra Mauro rock samples and six Hadley Rille and Spur Crater rock samples provided by the Apollo 14 and 15 missions. Genesis histories of some associated lunar surface features are traced back on the basis of obtained rock age values.

Husain, L.↗

NASA NTRS1971