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Geology topics

N.J. Trask

Publications and source records attributed to N.J. Trask.

At least 19 recordsLinked to original sources
USGS1986

U.S. Geological Survey research in radioactive waste disposal - Fiscal years 1983, 1984, and 1985

The report summarizes progress on geologic and hydrologic research related to the disposal of radioactive wastes. The research is described according to whether it is related most directly to: (1) high-level and transuranic wastes, (2) low-level wastes, or (3) uranium mill tailings. Included is research applicable to the identification and geohydrologic characterization of waste-disposal sites, to investigations of specific sites where wastes have been stored, and to studies of regions or environments where waste-disposal sites might be located. A significant part of the activity is concerned with techniques and methods for characterizing disposal sites and studies of geologic and hydrologic processes related to the transport and (or) retention of waste radionuclides.

Water-Resources Investigations Report↗
USGS1982

U.S. Geological Survey research in radioactive waste disposal; fiscal year 1980

The report summarizes progress on geologic and hydrologic research related to the disposal of radioactive wastes. The research is described according to whether it is related most directly to: (1) High-level and transuranic wastes; (2) Low-level wastes, or (3) Uranium mill tailings. Included is research applicable to the identification and geohydrologic characterization of waste-disposal sites, to investigations of specific sites where wastes have been stored, and to studies of regions or environments where waste-disposal sites might be located. A significant part of the activity is concerned with techniques and methods for characterizing disposal sites and studies of geologic and hydrologic processes related to the transport and (or) retention of waste radionuclides.

Open-File Report↗
USGS1981

Stratigraphy of the Caloris basin, Mercury

Caloris basin, Mercury’s youngest large impact basin, is filled by volcanic plains that are spectrally distinct from surrounding material. Post-plains impact craters of a variety of sizes populate the basin interior, and the spectra of the material they have excavated enable the thickness of the volcanic fill to be estimated and reveal the nature of the subsurface. The thickness of the interior volcanic plains is consistently at least 2.5 km, reaching 3.5 km in places, with thinner fill toward the edge of the basin. No systematic variations in fill thickness are observed with long-wavelength topography or azimuth. The lack of correlation between plains thickness and variations in elevation at large horizontal scales within the basin indicates that plains emplacement must have predated most, if not all, of the changes in long-wavelength topography that affected the basin. There are no embayed or unambiguously buried (ghost) craters with diameters greater than 10 km in the Caloris interior plains. The absence of such ghost craters indicates that one or more of the following scenarios must hold: the plains are sufficiently thick to have buried all evidence of craters that formed between the Caloris impact event and the emplacement of the plains; the plains were emplaced soon after basin formation; or the complex tectonic deformation of the basin interior has disguised wrinkle-ridge rings localized by buried craters. That low-reflectance material (LRM) was exposed by every impact that penetrated through the surface volcanic plains provides a means to explore near-surface stratigraphy. If all occurrences of LRM are derived from a single layer, the subsurface LRM deposit is at least 7.5–8.5 km thick and its top likely once made up the Caloris basin floor. The Caloris-forming impact would have generated a layer of impact melt 3–15 km thick; such a layer could account for the entire thickness of LRM. This material would have been derived from a combination of lower crust and upper mantle.

Icarus↗
USGS1976

Additional evidence of Mercurian volcanism

Evidence concerned with (1) the character and distribution of terrain surrounding fresh basins, (2) albedo, color and temporal differences between a basin rim and smooth plains on its floor, and (3) the stratigraphic relations and local distribution of smooth plains in the hilly and lineated terrain are cited as additional evidence for an internal origin of much of the Mercurian smooth plains. Altough the question of Mercurian volcanism should be kept open, this evidence together with that presented in an earlier paper suggests that volcanism occurred on Mercury early in its history.

Icarus↗
USGS1973

Preliminary geologic investigation of the Apollo 17 landing site

The Apollo 17 lunar module (LM) landed on the flat floor of a deep valley that embays the mountainous highlands at the eastern rim of the Serenitatis basin. Serenitatis, the site of a pronounced mascon, is one of the major multi-ringed basins on the near side of the Moon. The Taurus-Littrow valley, which is radial to the Serenitatis basis, is interpreted as a deep graben formed by structural adjustment of lunar crustal material to the Serenitatis impact.

Book chapter↗
USGS1971

Imaging of Mercury and Venus from a flyby

This paper describes the results of study of an imaging experiment planned for the 1973 Mariner Venus/Mercury flyby mission. Scientific objectives, mission constraints, analysis of alternative systems, and the rationale for final choice are presented. Severe financial constraints ruled out the best technical alternative for flyby imaging, a film/readout system, or even significant re-design of previous Mariner vidicon camera/tape recorder systems. The final selection was a vidicon camera quite similar to that used for Mariner Mars 1971, but with the capability of real time transmission during the Venus and Mercury flybys. Real time data return became possible through dramatic increase in the communications bandwidth at only modest sacrifice in the quality of the returned pictures. Two identical long focal length cameras (1500 mm) were selected and it will be possible to return several thousand pictures from both planets at resolutions ranging from equivalent to Earthbased to tenths of a kilometer at encounter. Systematic high resolution ultraviolet photography of Venus is planned after encounter in an attempt to understand the nature of the mysterious ultraviolet markings and their apparent 4- to 5-day rotation period. Full disk coverage in mosaics will produce pictures of both planets similar in quality to Earthbased telescopic pictures of the Moon. The increase of resolution, more than three orders of magnitude, will yield an exciting first look at two planets whose closeup appearance is unknown.

Icarus↗
USGS1971

Geologic setting of the Apollo 14 samples

The Apollo 14 lunar module landed in a region of the lunar highlands that is part of a widespread blanket of ejecta surrounding the Mare Imbrium basin. Samples were collected from the regolith developed on a nearly level plain, a ridge 100 meters high, and a blocky ejecta deposit around a young crater. Large boulders in the vicinity of the landing site are coherent fragmental rocks as are some of the returned samples.

Science↗
USGS1969

Geologic maps of early Apollo landing sites of set C

Comparison of the five potential early Apollo landing sites of set C reveals significant geologic similarities and differences. No two sites are identical; the geology of each should be considered in the interpretation of returned lunar samples and observations. Geologic maps of each site have been prepared at scales of 1:5,000, 1:25,000, and 1:100,000. Features emphasized on the 1:5,000-scale maps are common to all the sites and include mainly the widespread lunar regolith and small craters of varied age and origin. Because they cover the lunar surface and because mobility will be limited on early missions, these ubiquitous features will be the main objects of scientific inquiry during the first manned landings. Regional geologic differences among the sites are more apparent on the 1:25,000- and 1:100,000-scale maps. Mare materials in sites 2 and 3 belong mainly to the Imbrian System; the materials in site 3 appear to be younger than those in site 2. Mare materials in sites 4 and 5 belong entirely to the Eratosthenian System. Most materials in site 1 have been assigned to the Copernican System. They consist of a young mantle of relatively low-cohesion material that covers an older cratered terrain, probably part of the terrae. Typical mare material occurs only in the eastern extremity of site 1. Ray materials and secondary impact craters related to large rayed primary impact craters are present in several of the sites.

Open-File Report↗