Search NASA⌕ Search

SEARCH · Search NASA

Results for “ROCK”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Rock melting technology and geothermal drilling

National awareness of the potential future shortages in energy resources has heightened interest in exploration and utilization of a variety of geothermal energy (GTE) reservoirs. The status of conventional drilling of GTE wells is reviewed briefly and problem areas which lead to higher drilling costs are identified and R and D directions toward solution are suggested. In the immediate future, an expanded program of drilling in GTE formations can benefit from improvements in drilling equipment and technology normally associated with oil or gas wells. Over a longer time period, the new rock-melting drill bits being developed as a part of the Los Alamos Scientific Laboratory's Subterrene Program offer new solutions to a number of problems which frequently hamper GTE drilling, including the most basic problem - high temperature. Two of the most favorable characteristics of rock-melting penetrators are their ability to operate effectively in hot rock and produce glass linings around the hole as an integral part of the drilling process. The technical advantages to be gained by use of rock-melting penetrators are discussed in relation to the basic needs for GTE wells.

Rowley, J. C.↗
NASA NTRS1974

The dissection and consortium allocation of Apollo 17 lunar rocks from the boulder at station 7

The Apollo 17 astronauts removed four rocks samples to represent each of the lithologies they recognized in the boulder at station 7: sample 77215 from an off-white meter-sized block; sample 77075 from one of the thin dikes that cross the off-white block; 77115 from the blue-gray rock adjacent to the off-white block and apparently continuous with thin dikes that cross the block; sample 77135 of the tan-gray or green-gray vesicular rock adjacent to the blue-gray (77115) rock. A consortium of investigators has been organized to study the samples. Each sample shows a number of lithologic types in terms of clasts (or xenoliths) and matrices. A table shows how subsamples have been allocated for consortium study. Maps and photographs show the relations between subsample locations and lithologies for the two more dissected samples, 77115 and 77135.

Butler, P.↗
NASA NTRS1974

Igneous rocks from Apollo 16 rake samples

Results are reported for a study of seven holocrystalline feldspathic rocks (including a spinel troctolite and six melt rocks) and one mare basalt clast from the Apollo-16 rake samples. The composition and grain structure of each rock is described in detail. Only the spinel troctolite is considered a good candidate for a primary igneous cumulate formed during the original differentiation of the lunar crust. It is shown that the melt rocks probably resulted from shock melting followed by rapid crystallization of heterogeneous highland material and that compositional variations are probably due to mixing of various amounts of heterogeneous cumulates and KREEP components. It is suggested that the mare basalt clast may have been derived from Mare Fecunditatis, although the nearest mare to the Apollo-16 site is Nectaris.

Dowty, E.↗
NASA NTRS1974

Formational history of lunar rocks - Applications of experimental geochemistry of the opaque minerals

Experimental data on the cooling histories of lunar rocks are presented along with a descriptive mineralogy of certain opaque minerals in Apollo 17 samples. Lunar rocks having Zr partitionings of coexisting ilmenite and ulvospinel indicative of high-temperature equilibrium (above 1000 C) appear to have cooled rapidly to temperatures below 800-900 C. The Ti content of troilite coexisting with ilmenite can be used to differentiate rock fragments which are mineralogically and texturally similar. It is found that Cr and Mg partitionings between coexisting armalcolite and ilmenite vary notably between rocks so that they can be used to distinguish otherwise similar samples. The spinels are analyzed as varieties of chromian ulvospinel and titanian chromite.

Taylor, L. A.↗
NASA NTRS1974

Opaque mineralogy - Apollo 17, rock 75035

Rock 75035 is a medium-grained, holocrystalline, subophitic ilmenite basalt collected from the rim of Camelot Crater, and is believed to represent the subfloor basalts of the Taurus-Littrow valley. The rock consists of the major minerals pyroxene (45%), plagioclase (31%), and ilmenite (17%). Minor minerals include cristobalite (about 5%), troilite, native Fe, tranquillityite, baddeleyite, zirconolite, and rare ulvospinel. No olivine or armalcolite was observed in the specimen 75035,76. Mineralogically and chemically, as well as in age, this rock is similar to others collected from Camelot and other stations during the Apollo 17 mission. These rocks are almost identical to the Type B ilmenite basalts of Mare Tranquillitatis.

Meyer, H. O. A.↗
NASA NTRS1974

Beta-FeOOH, akaganeite, in lunar rocks

Experiments were conducted to determine the nature of the alteration process in lunar rocks. Mixtures of 10 wt.% Fe + 10 wt.% FeCl2 + 80 wt.% basalt (terrestrial) were pelletized and allowed to set for 48 hrs at 25 C, at 40% and at 100% relative humidity. The end products were examined by reflected-light microscopy and by X-ray diffraction. The degree of reaction appears to depend upon the amount of FeCl2, the availability of water and the Ni content of the metallic Fe. The experiments showed the extremely rapid rate at which the oxyhydration can occur in air and that the product is beta-FeOOH. The data from the FeOOH mineral in rock 66095 were compared with those obtained from synthetic beta-FeOOH and found to be identical. The 'rust' in the Apollo 16 rocks could result from oxyhydration of the samples, caused by water vapor contamination, all or part of which occurred in the Apollo spacecraft and/or upon return to earth. The akageneite (beta-FeOOH) in lunar rocks could be entirely of terrestrial origin as originally suggested by Taylor et al. (1973).

Taylor, L. A.↗
NASA NTRS1974

The contamination of lunar highland rocks by KREEP - Interpretation by mixing models

A mixing model method was used to determine the component abundance in the Apollo 16 and 17 soils. This method uses the chemical composition of the soils for up to 30 elements and a weighted least-squares mixing model technique. Elements included in the calculations are: Si, Ti, Al, Ca, Fe, Mg, P, Cr, Mn, Na, K, Rb, Ba, U, Th, La, Ce, Sm, Eu, Sr, Yb, Y, Sc, V, Zr, Nb, Co, Ni, Li, Au, and Ir. The method was used to examine the possibility that some of the highland rocks such as VHA and low-K Fra Mauro basalt are mixtures. The results of the mixing model calculations show that it is possible that these rocks are mixtures of KREEP, troctolite, 'anorthosites', and a meteoritic component. The Rb-Sr systematics are consistent with such a model for the genesis of the highland rocks. KREEP has high relative concentrations of Rb, U, and radiogenic Sr and Pb and its model age of about 4.4 AE dominates the model age of all the 'contaminated' highland rocks.

Schonfeld, E.↗
NASA NTRS1974

Micrometeoroid abrasion of lunar rocks - A Monte Carlo simulation

A Monte Carlo computer model simulating the randomness of the impact process both in space and in time is developed in order to provide insight into lunar rock erosion by single particle abrasion and into bombardment history of fractional surface areas of lunar rocks. Microcrater frequencies derived from lunar rocks are used to calculate magnitude and probability of each cratering event, and experimental cratering results are employed to determine the eroded volumina for individual crater sizes. It is shown that a fractional surface area of a lunar rock sample may have a completely different bombardment history, and that the exposure histories and actual erosion depths of the surfaces vary accordingly and are highly heterogeneous. A minimum erosion rate of 0.3 to 0.6 mm for the past one million years is obtained.

Hoerz, F.↗
NASA NTRS1975

Rocks 60618 and 65785 - Evidence for admixture of KREEP in lunar impact melts

We present evidence to support the hypothesis that the fine-grained, basaltic-textured portions of rocks 60618 and 65785 were produced by impact melting of the coarse-grained spinel-olivine anorthosite (60618) and spinel troctolite (65785) portions, coupled with admixture of approximately 33% and 63%, respectively, material of alkalic high-alumina basalt (KREEP) composition. The abundance of impact-modified rocks at the Apollo 16 site with compositional similarities to the impact melts reported here, suggests that the relations observed in these rocks are indicative of widespread impact mixing with KREEP in rocks of the lunar highlands.

Keil, K.↗
NASA NTRS1976

Textural remanence - A new model of lunar rock magnetism

In reexamining the accumulated magnetic data on lunar rocks, several common patterns of magnetic behavior are recognized. Their joint occurrence strongly suggests a new model of lunar rock magnetism, which is based on partial preferred textural alignment of the spontaneous moments of magnetic grains without requiring the existence of ancient lunar magnetic fields. This magnetic fabric, mimetic to locally oriented petrofabric, gives rise to an apparent 'textural remanent magnetization'. In order to account for the observed intensity of 'stable remanence' in lunar rocks, only a minute fraction (0.001 to 0.00001) of the single-domain iron grains present need be preferentially aligned. Several mechanisms operating on the lunar surface, including shock and diurnal thermal cycling, appear adequate for producing the required type and degree of magnetic alignment in all lunar rock classes. The model is supported by a wide variety of direct and indirect evidence, and its predictions (e.g., regarding anisotropic susceptibility and remanence acquisition) can be experimentally tested.

Brecher, A.↗
NASA NTRS1976

Atmospheric rare gases in lunar rock 60015

Aliquots of lunar rock 60015 were subjected to various types of exposure and handling designed to produce terrestrial contamination, in order to test the possibility of a terrestrial origin for the terrestrial-like trapped Xe reported for lunar rock samples. Crushing the rock produced up to order-of-magnitude increases in the abundances of Ar, Kr, and Xe relative to the millimeter-sized chips of 60015 previously analyzed. Contrary to expectations for atmospheric contamination, high temperatures (above 1000 C) were necessary to remove about 75% of the trapped Kr and Xe, and the rare-gas elemental abundance ratios differed from those in terrestrial samples believed to have occluded atmospheric gases. It is concluded, on the basis of similar temperature-release profiles and elemental-fractionation patterns, that the trapped Xe observed in all these 60015 analyses is atmospheric contamination. Such a conclusion cannot unequivocally be drawn for other lunar rocks containing terrestrial-like Xe, but the present results demonstrate that arguments based on high extraction temperatures and elemental abundance ratios cannot be useful to rule out rare-gas atmospheric contamination in such samples.

Niemeyer, S.↗
NASA NTRS1976

Carbides in lunar soils and rocks

Carbides and the surrounding metal of eight particles from Apollo 14, 16, and 17 soils were analyzed for C, Fe, Ni, and Co with the electron microprobe. In addition, carbide-containing metal particles in two Apollo 17 rocks were studied. Carbide-metal assemblages were found in anorthositic hornfels, melt rock, and agglutinate, but not in any primary igneous rocks. Carbon measurements show that cohenite is the carbide phase present in all the samples. Cohenite exsolves from the carbon-rich metal phase during cooling of the lunar metal particle in the host rocks or soil fragments. Measurements of two-phase interface compositions indicate equilibration for carbides and metal during cooling below 600 C and possibly below 500 C.

Goldstein, J. I.↗
NASA NTRS1977

Comparison of lunar rocks and meteorites: Implications to histories of the moon and parent meteorite bodies

There are many similarities between lunar samples and stone meteorites. Lunar samples, especially from the highlands, indicate that they have been affected by complex and repeated impact processes. Similar complex and repeated impact processes have also been operative on the achondritic and chondritic meteorites. Similarities between lunar and meteoritic rocks are discussed as follows: (1) Monomict and polymict breccias occur in lunar rocks, as well as in achondritic and chondritic meteorites, having resulted from complex and repeated impact processes; (2) Chondrules are present in lunar meteorites, as well as in a few achondritic and most chondritic meteorites. They apparently crystallized spontaneously from molten highly supercooled droplets which may have formed from impact melts or, perhaps, volcanic processes (as well as from the solar nebula, in the case of meteoritic chondrites); (3) Lithic fragments vary from little modified (relative to the apparent original texture) to partly or completely melted and recrystallized lithic fragments. Their detailed study allows conclusions to be drawn about their parent rock types and their origin, thereby gaining insight into preimpact histories of lunar and meteoritic breccias. There is evidence that cumulate rocks were involved in the early history of both moon and parent meteorite bodies.

Prinz, M.↗
NASA NTRS1977

The surface abundance and stratigraphy of lunar rocks from data about their albedo

The data pf ground-based studies and surveys of the lunar surface by the Zond and Apollo spacecraft have been used to construct an albedo map covering 80 percent of the lunar sphere. Statistical analysis of the distribution of areas with various albedos shows several types of lunar surface. Comparison of albedo data for maria and continental areas with the results of geochemical orbital surveys allows the identification of the types of surface with known types of lunar rock. The aluminum/silcon and magnesium/silicon ratios as measured by the geochemical experiments on the Apollo 15 and Apollo 16 spacecraft were used as an indication of the chemical composition of the rock. The relationship of the relative aluminum content to the age of crystalline rocks allows a direct dependence to be constructed between the mean albedo of areas and the age of the rocks of which they are composed.

Shevchenko, V. V.↗
NASA NTRS1977

Exposure ages and erosion rates for lunar rocks

The available data on the effects of particle bombardment of lunar rocks are examined, taking into account rare gas data, neutron capture products, radioactive nuclei, and particle tracks. Attention is given to exposure ages, questions concerning the validity of exposure ages, the location of rocks during irradiation, the criteria for valid crater ages, special problems regarding lunar breccias, surface residence times from long lived radioactive nuclei, surface residence times from galactic cosmic ray track data, rocks with simple surface exposure, rocks with complex surface exposure, limits on surface residence times, suntan and subdecimeter ages, erosion rates, and a number of case histories related to exposure age measurements as applied to the problem of the dating of impact events.

Burnett, D. S.↗
NASA NTRS1977

Lunar Science Conference, 8th, Houston, Tex., March 14-18, 1977, Proceedings. Volume 1 - The moon and the inner solar system. Volume 2 - Petrogenetic studies of mare and highland rocks. Volume 3 - Planetary and lunar surfaces

Solar system processes are considered along with the origin and evolution of the moon, planetary geophysics, lunar basins and crustal layering, lunar magnetism, the lunar surface as a planetary probe, remote observations of lunar and planetary surfaces, earth-based measurements, integrated studies, physical properties of lunar materials, and asteroids, meteorites, and the early solar system. Attention is also given to studies of mare basalts, the kinetics of basalt crystallization, topical studies of mare basalts, highland rocks, experimental studies of highland rocks, geochemical studies of highland rocks, studies of materials of KREEP composition, a consortium study of lunar breccia 73215, topical studies on highland rocks, Venus, and regional studies of the moon. Studies of surface processes, are reported, taking into account cratering mechanics and fresh crater morphology, crater statistics and surface dating, effects of exposure and gardening, and the chemistry of surfaces.

Merril, R. B.↗
NASA NTRS1977

Petrology of Apollo 15 black-and-white rocks 15445 and 15455 - Fragments of the Imbrium impact melt sheet

The paper describes two macroscopically similar black-and-white rocks, 15445 and 15455, which were collected from the rim of Spur Crater on the Apennine Front. The two Apollo 15 rocks are very similar in chemistry and clast population, but the matrix of 15455 is finer grained than that of 15445. The 15445 sample contains a lithic clast assemblage of plutonic/metamorphic spinel troctolite, troctolite, norite, and anorthosite, and its fine-grained vesicular black coherent matrix consists of a melt-bonded aggregate of small mineral clasts which are mainly olivine, plagioclase, and pink spinel. The two rocks are distinct from any other large samples from the Apollo 15 site. It is suggested that the rocks are samples of an impact melt sheet which forms a bedrock unit of the Apennine Front, and that this melt sheet did not form in a local small-scale event but was produced during the Imbrium impact event.

Ryder, G.↗
NASA NTRS1977

SCCRV, a major component of highlands rocks

An investigation was conducted of the composition of lunar highlands samples rich in mafics. Most of the samples were Apollo 16 rocks. The compositional data for 13 lunar rocks are listed in a table. The nonpristine rocks 64815 and 77545 having essentially identical KREEP contents of about 32% have very similar, high contents of the mafic component SCCRV. The same amounts of rather similar ingredients were mixed at locations 1000 km apart. The composition of SCCRV is discussed. According to the three most plausible hypotheses for the origin of SCCRV which are proposed the SCCRV is primordial material, SCCRV consists entirely or mainly of a single type of lunar rock, or SCCRV resulted from the mixing of two or more lunar materials.

Wasson, J. T.↗