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Swann, G. A.

Publications and source records attributed to Swann, G. A..

16 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Some observations on the geology of the Apollo 15 landing site

High resolution (panoramic) and high geometric fidelity (metric) photos were taken from orbit of the lunar landing sites. Gamma ray and X-ray fluorescence spectroscopic measurement were taken to determine regional chemical composition of the Moon. Distinctive features of the Apennine Bench Formation are described. The structurally controlled topography of the Apennine Bench Formation is suggested of a lava channel or collapsed lava tube.

Swann, G. A.↗
NASA NTRS1974

A method for estimating the absolute ages of small Copernican craters and its application to the determination of Copernican meteorite flux

Cosmic ray exposure ages of ejecta from Copernican craters in various stages of erosion can be used to construct a curve from which the time of formation of craters in the Copernican System can be estimated on the basis of their morphology. Use of this curve to estimate the flux for particles that formed 75-1000 m craters during six increments of Copernican time in an area of Mare Serenitatis suggests that the flux has steadily increased throughout Copernican time. These results are considered to be preliminary until more work of this kind has been done for other mare areas of the moon.

Swann, G. A.↗
NASA NTRS1972

Documentation of Apollo 15 samples

A catalog is presented of the documentation of Apollo 15 samples using photographs and verbal descriptions returned from the lunar surface. Almost all of the Apollo 15 samples were correlated with lunar surface photographs, descriptions, and traverse locations. Where possible, the lunar orientations of rock samples were reconstructed in the lunar receiving laboratory, using a collimated light source to reproduce illumination and shadow characteristics of the same samples shown in lunar photographs. In several cases, samples were not recognized in lunar surface photographs, and their approximate locations are known only by association with numbered sample bags used during their collection. Tables, photographs, and maps included in this report are designed to aid in the understanding of the lunar setting of the Apollo 15 samples.

Sutton, R. L.↗
NASA NTRS1972

Preliminary geologic investigation of the Apollo 15 landing site

The Apollo 15 lunar module (LM) landed on the mare surface of Palus Putredinis on the eastern edge of the Imbrium Basin. The site is between the Apennine Mountain front and Hadley Rille. The objectives of the mission, in order of decreasing priority, were description and sampling of three major geologic features-the Apennine Front, Hadley Rille, and the mare. The greater number of periods of extravehicular activity (EVA) and the mobility provided by the lunar roving vehicle (ROVER) allowed much more geologic information to be obtained from a much larger area than those explored by previous Apollo crews. A total of 5 hours was spent at traverse station stops, and the astronauts transmitted excellent descriptions of the lunar surface while in transit between stations.

Swann, G. A.↗
NASA NTRS1972

Geology of Hadley Rille

The regional setting, external and internal shape, and materials of Hadley Rille near the Apollo 15 landing site are described. The petrography presented includes lithologies, regolith, talus, and outcrops. The stratigraphy exposed on the rille wall is also considered.

Howard, K. A.↗
NASA NTRS1972

Geology of Hadley Rille.

Apollo 15 data support the concept that Hadley Rille is a giant collapsed lava tube that originated at its south end. The south half of the rille is sinuous and the bends are not structurally controlled, whereas the north half of the rille follows pre-mare structural troughs. Most of the rille has a V-shaped profile apparently formed by recession of the rims and coalescence of talus from both sides. The rille is scalloped and discontinuous locally, and the deepest parts consistently are the widest. This is a different relationship from that shown by river channels, but can instead be explained by collapse, with most extensive foundering at the deepest points. The upper 60 meters of the walls of the rille at the Apollo 15 site expose several layers of mare basalt. Most are massive units averaging at least 10 m thick; others are layered. Numerous talus blocks derived from the massive outcrops are 10 to 30 m across. The lunar flows are thus both thick and little jointed. The outcrop ledge and blocky talus derived from it are absent where the rille abuts Apennine massifs, showing that the rille cuts through the mare basalt and against massif material.

Howard, K. A.↗
NASA NTRS1972

Geology of the Apollo 14 landing site.

Apollo 14 landed in the Fra Mauro region of the moon, within about 1,100 m of a 90 m high ridge of the Fra Mauro formation, interpreted as being ejecta from the Imbrium Basin. The primary geologic objective of the mission was to sample ejecta from Cone Crater, which is 340 m in diameter and penetrates at least 60 m into the ridge. Data from the mission strongly support the Imbrian ejecta origin for the Fra Mauro formation. Returned samples and photographs show that ejecta from Cone Crater is composed of composite breccias that include multiple clasts of still older, pre-Imbrian, breccias. Cone Crater ejecta displays a wide range of thermal metamorphism effects. Samples from the valley where the Lunar Module landed, which was not on a recognizable ray of ejecta from Cone Crater, are predominantly fines and poorly consolidated breccias formed by the disintegration of Fra Mauro rocks and probably are not volcanic rocks as had been postulated before the mission.

Sutton, R. L.↗
NASA NTRS1971

Preliminary description of Apollo 15 sample environments

Approximately 78 kg of lunar rock and soil samples were returned by Apollo 15. The rather complete documentation of the locations of nearly all of the samples allows for relating the samples to the specific and detailed geologic environments from which they were collected. This is especially important in an area as geologically complex as the Hadley-Apennine site. All of the material presented was derived from the pre-mission photogeologic maps, lunar surface television video tapes, air-to-ground transcript and crew debriefings, photographs taken on the lunar surface by the Apollo 15 crew, and information supplied by the Lunar Sample Preliminary Examination team from which the samples were categorized into groups consisting of, broadly, basalts and breccias. The breccias are considered loosely in terms of coherent breccias and soil breccias.

Swann, G. A.↗