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King, E. A.

Publications and source records attributed to King, E. A..

25 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Late Eocene rings around the earth

The suggestion of O'Keefe (1980) that the terminal Eocene event was caused by rings of tektite material encircling the earth is discussed. It is argued that the assumption that the tektites are of lunar volcanic origin is unwarranted and contrary to existing data, including the lack of lunar rocks of suitable composition, the lack of lunar rocks of the correct age, the lack of evidence that the North American tektites fell throughout a sedimentary rock column of a few million years, and the nondetection of a tektite with a measurable cosmic ray exposure age. Alternatively, it is suggested that the terminal Eocene event may be associated with volcanic ash, air-fall tuff and bentonite in the late Eocene. O'Keefe replies that the hypothesis of the terrestrial origin of the tektites conflicts with the laws of physics, for example in the glass structure and shaping of the tektites. Furthermore, evidence is cited for lunar rocks of the proper major-element composition and ages, and it is noted that the proposed solar Poynting-Robertson effect would account for the particle fall distributions and cosmic ray ages.

King, E. A.↗
NASA NTRS1978

The Inman, McPherson County, Kansas meteorite

The Inman meteorite (find, 1966) is a single relatively unweathered stone of 7.25 kg that contains fresh metal and only a few weathering products away from fractures. It has a pronounced chondritic texture, with 38 vol% of the meteorite being made up of chondrules of virtually all textural types. The recalculated bulk analysis, in particular ratios involving iron content, indicate that Inman is an L-group chondrite. The pronounced chondritic texture; the compositional variation of olivine, pyroxene, chromite, and ilmenite; and the presence of a fine-grained nearly opaque matrix, glass, and twinned monoclinic low-Ca pyroxene indicate that the chondrite belongs to petrologic type 3.

Keil, K.↗
NASA NTRS1978

Allende dark inclusions

Throughout many samples of the Allende meteorite there are black-to-light-gray lithic inclusions (xenoliths) that have been found to be different from the bulk meteorite both petrographically and chemically. They contain information that reflects either a lithologic range on the Allende parent meteorite body and/or foreign carbonaceous chondrite fragments. Studies of six of these dark inclusions are reported in the present paper.

Fruland, R. M.↗
NASA NTRS1977

The Del Rio ataxite, Texas

Basic data are presented on the Del Rio, Nordheim, and Monahans ataxites found in Texas. Results are reported for bulk-chemistry analysis, metallographic observations, and electron-microprobe analysis of the Del Rio meteorite. It is shown that Del Rio is distinctly different from the other two ataxites in terms of nickel, phosphorous, and carbon content, and is composed of at least three coarse grains in different crystallographic orientations. All the kamacite in Del Rio is found to have transformation structures that are probable shock products, and minor inclusions of daubreelite, schreibersite, and troilite are observed. It is concluded that Del Rio was apparently mildly shocked prior to its fall.

Henderson, E. P.↗
NASA NTRS1975

Size and modal analyses of fines and ultrafines from some Apollo 17 samples

Scanning electron and optical microscopy techniques have been used to determine the grain-size frequency distributions and morphology-based modal analyses of fine and ultrafine fractions of some Apollo 17 regolith samples. There are significant and large differences between the grain-size frequency distributions of the less than 10-micron size fraction of Apollo 17 samples, but there are no clear relations to the local geologic setting from which individual samples have been collected. This may be due to effective lateral mixing of regolith particles in this size range by micrometeoroid impacts. None of the properties of the frequency distributions support the idea of selective transport of any fine grain-size fraction, as has been proposed by other workers. All of the particle types found in the coarser size fractions also occur in the less than 10-micron particles. In the size range from 105 to 10 microns there is a strong tendency for the percentage of regularly shaped glass to increase as the graphic mean grain size of the less than 1-mm size fraction decreases, both probably being controlled by exposure age.

Greene, G. M.↗