New Technology/Old Technology: Comparing Lunar Grain Size Distribution Data and Methods

Laser diffraction technology generates reproducible grain size distributions and reveals new structures not apparent in old sieve data. The comparison of specific sieve fractions with the Microtrac distribution curve generated for those specific fractions shows a reasonable match for the mean of each fraction between the two techniques, giving us confidence that the large existing body of sieve data can be cross-correlated with new data based on laser diffraction. It is well-suited for lunar soils, which have as much as 25% of the material in the less than 20 micrometer fraction. The fines in this range are of particular interest because they may contain a record of important space weathering processes

Laser Diffraction Techniques Replace Sieving for Lunar Soil Particle Size Distribution Data

Sieving was used extensively until 1999 to determine the particle size distribution of lunar samples. This method is time-consuming, and requires more than a gram of material in order to obtain a result in which one may have confidence. This is demonstrated by the difference in geometric mean and median for samples measured by [1], in which a 14-gram sample produced a geometric mean of approx.52 micrometers, whereas two other samples of ~1.5 grams resulted in gave means of approx.63 and approx.69 micrometers. Sample allocations for sieving are typically much smaller than a gram, and many of the sample allocations received by our lab are 0.5 to 0.25 grams in mass. Basu [2] has described how the finest fraction of the soil is easily lost in the sieving process, and this effect is compounded when sample sizes are small

An unusual clast in lunar meteorite MacAlpine Hills 88105: a unique lunar sample or projectile debris?

Lunar meteorite MacAlpine Hills (MAC) 88105 is a well-studied feldspathic regolith breccia dominated by rock and mineral fragments from the lunar highlands. Thin section MAC 88105,159 contains a small rock fragment, 400 × 350 μm in size, which is compositionally anomalous compared with other MAC 88105 lithic components. The clast is composed of olivine and plagioclase with minor pyroxene and interstitial devitrified glass component. It is magnesian, akin to samples in the lunar High Mg-Suite, and also alkali-rich, akin to samples in the lunar High Alkali Suite. It could represent a small fragment of late-stage interstitial melt from an Mg-Suite parent lithology. However, olivine and pyroxene in the clast have Fe/Mn ratios and minor element concentrations that are different from known types of lunar lithologies. As Fe/Mn ratios are notably indicative of planetary origin, the clast could either (1) have a unique lunar magmatic source, or (2) have a nonlunar origin (i.e., consist of achondritic meteorite debris that survived delivery to the lunar surface). Both hypotheses are considered and discussed

Interim site characterization report and ground-water monitoring program for the Hanford site solid waste landfill

Federal and state regulations governing the operation of landfills require utilization of ground-water monitoring systems to determine whether or not landfill operations impact ground water at the point of compliance (ground water beneath the perimeter of the facility). A detection-level ground-water monitoring system was designed, installed, and initiated at the Hanford Site Solid Waste Landfill (SWL). Chlorinated hydrocarbons were detected at the beginning of the ground-water monitoring program and continue to be detected more than 1 year later. The most probable source of the chlorinated hydrocarbons is washwater discharged to the SWL between 1985 and 1987. This is an interim report and includes data from the characterization work that was performed during well installation in 1987, such as field observations, sediment studies, and geophysical logging results, and data from analyses of ground-water samples collected in 1987 and 1988, such as field parameter measurements and chemical analyses. 38 refs., 27 figs., 8 tabs

Western oceanus procellarum as seen by c1xs on chandrayaan-1

We present the analysis of an X-ray fluorescence (XRF) observation of the western part of Oceanus Procellarum on the Moon’s nearside made by the Chandrayaan-1 X-ray Spectrometer on 10th February 2009. Through forward modelling of the X-ray spectra, we provide estimates of the MgO/SiO2 and Al2O3/SiO2 ratios for seven regions along the flare’s ground track. These results are combined with FeO and TiO2 contents derived from Clementine multispectral reflectance data in order to investigate the compositional diversity of this region of the Moon. The ground track observed consists mainly of low-Ti basaltic units, and the XRF data are largely consistent with this expectation. However, we obtain higher Al2O3/SiO2 ratios for these units than for most basalts in the Apollo sample collection. The widest compositional variation between the different lava flows is in wt% FeO content. A footprint that occurs in a predominantly highland region, immediately to the north of Oceanus Procellarum, has a composition that is consistent with mixing between low-Ti mare basaltic and more feldspathic regoliths. In contrast to some previous studies, we find no evidence for systematic differences in surface composition, as determined through X-ray and gamma-ray spectroscopy techniques

Ground-water monitoring compliance plan for the Hanford Site Solid Waste Landfill

Washington state regulations required that solid waste landfill facilities have ground-water monitoring programs in place by May 27, 1987. This document describes the well locations, installation, characterization studies and sampling and analysis plan to be followed in implementing the ground-water monitoring program at the Hanford Site Solid Waste Landfill (SWL). It is based on Washington Administrative Code WAC 173-304-490. 11 refs., 19 figs., 4 tabs

Impact-generated volatile movement and redistribution in the Rose City meteorite

Ordinary chondrites contain textures and mineralogies which indicate a range in intensity of shock and thermal metamorphism. It has been proposed that the metamorphic sequence in ordinary chondrites is the result of thermal metamorphism in ejecta blankets deposited by impact events on the parent meteorite bodies. Because of the association of vapor phase crystallization with recrystallized (thermally-metamorphosed) lunar breccias, a search for vapor phase crystallization was undertaken with the Rose City meteorite (H-group). The Rose City meteorite is a high iron chondrite that underwent brecciation, shock-melting, vaporization and recrystallization in an impact event about 400 million years ago as interpreted from rare gas data. It contains a variety of lithologies: (1) clasts of moderately-shocked H6 lithology, (2) matrix, between clasts, of shock-melted and recrystallized silicate veins, depleted in metal and sulfide but containing numerous mineral fragments and vesicles, (3) matrix veins of metal and sulfide with a cotectic texture, (4) clasts in which the metal-sulfide and silicate portions show a range in degree of shock melting. Many of the larger clasts which are still coherent are surrounded by a band of metal-sulfide with the same cotectic texture common in the matrix metal bands. A striking array of apparently vapor-grown crystals in cavities was found in both the recrystallized matrix and in the clasts of the Rose City meteorite, using the scanning electron microscope and energy dispersive x-ray analyzer. Euhedral to subhedral crystals of troilite, iron, iron-nickel, pyroxene, olivine, and apatite were found attached to the walls of vugs. Similar morphologies arid mineralogies of crystals in vuggy lunar breccias and the Rose City meteorite suggest similar processes caused loss of volatiles plus redistribution of volatiles in both ordinary chondrites and lunar breccias. Cooling of hot ejecta blankets on parent meteorite bodies would include movements of vapors (such as oxides, halides, sulfides, iron) from hotter to cooler areas, and result in eventual loss of noncondensable species and deposition of condensable species in cooler areas. This would explain some of the volatile depletions in ordinary chondrites. Cooling of large thermally-zoned ejecta blankets would partially explain the progressive thermal metamorphism of ordinary chondrites with the more recrystallized meteorites originating in the hotter zones of the ejecta blanket.Earth and Atmospheric Sciences, Department o

Resource conservation and recovery act ground-water monitoring projects for Hanford facilities: Progress report for the period July 1 to September 30, 1988: Volume 2, Appendices

This is Volume 2 of a two-volume set of documents that describes the progress of 12 Hanford Site ground-water monitoring projects for the period July 1 to September 30, 1988. This volume provides those drilling logs and well inspection/completion reports inadvertently left out of last quarter's report for the 216-A-36B Crib (Appendix A) and as-built diagrams, drilling logs, and geophysical logs for wells drilled this quarter near the 2101-M Pond. Volume 1 discusses the 12 projects

Resource Conservation and Recovery Act ground-water monitoring projects for Hanford facilities: Progress report for the period July 1 to September 30, 1988: Volume 1, Text

This report describes the progress of 12 Hanford ground-water monitoring projects for the period July 1 to September 30, 1988. During this quarter, field activities at the 300 Area process trenches, the Nonradioactive Dangerous Waste Landfill, the 183-H Solar Evaporation Basins, the 1324-N/NA Surface Impoundment and Percolation Ponds, the 1301-N and 1325-N Liquid Waste Disposal Facilities, and the 216-A-36B Crib consisted of ground-water sampling and analyses, and water-level monitoring. The 200 Area Low-Level Burial Grounds section includes well development data, sediment analysis, and water-level measurements. Ground-water sampling was begun at this site, and results will be included in next quarter's report. Twelve new wells were installed during the quarter, two at the 216-A-29 Ditch, size at the 216-A-10 Crib, and four at the 216-B-3 Pond. Preliminary characterization data for these new wells are included in this report. Driller's logs and other drilling and site characterization data will be provided in the next quarterly report. At the 2101-M Pond, construction was completed on four wells, and initial ground-water samples were taken. The drilling logs, geophysical logging data, and as-built diagrams are included in this report in Volume 2. 19 refs., 24 figs., 39 tabs