Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “volcanic rocks”

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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Poikilitic KREEP impact melts in the Apollo 14 white rocks

A KREEP-rich fragment-laden melt series in the Apollo 14 white rocks is interpreted to be the result of impact into a source region possibly consisting of KREEP volcanic rock flows, underlain and surrounded by anorthositic-troctolitic highlands rocks. The melt groundmass is a high-alumina, high-K2O Fra Mauro basalt, enriched in plagioclase. A poikilitic texture is developed in the coarser members of the series, possibly as a result of the impact melt being seeded with relict plagioclase nuclei.

Ryder, G.↗
NASA NTRS2015

Volcanism on Mars

Spacecraft exploration has revealed abundant evidence that Mars possesses some of the most dramatic volcanic landforms found anywhere within the solar system. How did a planet half the size of Earth produce volcanoes like Olympus Mons, which is several times the size of the largest volcanoes on Earth? This question is an example of the kinds of issues currently being investigated as part of the space-age scientific endeavor called "comparative planetology." This chapter summarizes the basic information currently known about volcanism on Mars. The volcanoes on Mars appear to be broadly similar in overall morphology (although, often quite different in scale) to volcanic features on Earth, which suggests that Martian eruptive processes are not significantly different from the volcanic styles and processes on Earth. Martian volcanoes are found on terrains of different age, and Martian volcanic rocks are estimated to comprise more than 50% of the Martian surface. This is in contrast to volcanism on smaller bodies such as Earth's Moon, where volcanic activity was mainly confined to the first half of lunar history (see "Volcanism on the Moon"). Comparative planetology supports the concept that volcanism is the primary mechanism for a planetary body to get rid of its internal heat; smaller bodies tend to lose their internal heat more rapidly than larger bodies (although, Jupiter's moon Io appears to contradict this trend; Io's intense volcanic activity is powered by unique gravitational tidal forces within the Jovian system; see "Volcanism on Io"), so that volcanic activity on Mars would be expected to differ considerably from that found on Earth and the Moon.

Mars↗
NASA NTRS1988

The Sudbury Structure (Ontario, Canada) and Vredefort Structure (South Africa): A comparison

Both the Sudbury Structure (SS) and the Witwatersrand Basin surrounding the Vredefort Structure (VS) host some of the most important base and precious metal deposits on earth. In both structures Precambrian igneous, sedimentary and volcanic rocks were affected by the structure forming process, either meteorite impact or endogenic explosion, or as some VS workers propose, by high strain tectonics. Besides these general features there are some geological and geophysical characteristics that are strikingly similar in both structures. There are, however, some obvious differences. Directly related to the structure forming processes are breccias in the footwall rocks of both structures. Pseudotachylite breccias occurring in both structures display great similarities. Chemical and physical characteristics of the pseudotachylites are similar in both structures. Both structures are characterized by overturned collar rocks, not evident everywhere around the SS. The VS is rimmed by an up or overturned collar of sediments and volcanics of the Witwatersrand, Ventersdorp and Transvaal Supergroups. Drilling information proved that the strata of the Witwatersrand Supergroup in the south of the VS are lying horizontally. Shockmetamorphic features such as planar microdeformations in rock forming minerals and shatter cones are present in both structures in the footwall rocks and in the SS also in the breccias of the OF. Both structures have large geophysical anomalies associated with them. In both structures the anomalies were interpreted as being caused by mafic-ultramafic complexes underlying the structures.

Dressler, B. O.↗
NASA NTRS2001

Ventifact Formation in the Mojave Desert: Field Analogs for Martian Processes

Two field studies in the Mojave Desert, California, shed light on processes of ventifact formation. The field sites are located on a ridge at Little Cowhole Mountain, which lies approximately 12 km south of Baker, and on an unnamed ridge situated along the northern boundary of the Mojave River Sink (Rasor Road site). The rocks at Little Cowhole Mountain are a blue-grey marble/dolomite, whereas those at Rasor Road are Miocene volcanic rocks (basalt). At both sites the abrasive agent is a fine-grained aeolian sand which was probably derived largely from the Mojave River. There are minimal modem inputs of sand to either site: abrasion occurs as a result of unique climatic and topographic conditions which allow pre-existing sand to be recycled from one aspect of the ridge to the other. Climatic conditions are well suited for ventifact formation. Owing, to the dry climate (marked by low average relative humidity, infrequent dew, and low annual rainfall), rates of chemical weathering are low. Where resurfacing of the rocks by sand abrasion proceeds at a rate greater than weathering, the ventifacts are considered "active." Active ventifacts are found atop and straddling the ridge crests, in the zone of maximum wind velocity and sediment supply. Inactive ventifacts occur where modem weathering Processes exceed abrasion rates; principally on the basal two-thirds of the hillslope, where wind velocity and sediment supply are lower. At intermediate locations between the slope base and crest, ventifacts are either active or inactive, depending on local conditions. The presence of relict ventifacts at the study sites, as well as elsewhere in the eastern Mojave Desert, suggests that the conditions for venti fact formation must have been more intense and extensive in the past. Together, the studies illustrate that the processes that interact to form ventifacts are highly complex, and must be studied at many scales. Small-scale effects, such as local topography, plant cover, or even the spatial distribution of boulders, strongly influence the formation of each individual ventifact. Mesoscale effects (hillslope form, total availability of sediment, seasonality of winds, etc.) determine the distribution of overall erosional energy and the location of active and relict forms.

Laity, J. E.↗
NASA NTRS2003

Osmium Isotope and Highly Siderophile Element Compositions of Lunar Orange and Green Glasses

The absolute and relative abundances of the highly siderophile elements (HSE) present in planetary mantles are primarily controlled by: 1) silicate-metal partitioning during core-mantle differentiation, 2) the subsequent addition of HSE to mantles via continued planetary accretion. Consequently, constraints on the absolute and relative abundances of the HSE in the lunar mantle will provide unique insights to the formation and late accretionary history of not only the Moon, but also Earth. Determining the HSE content of the lunar mantle, however, has proven difficult, because no bona fide mantle rocks have been collected from the moon. The only materials presently available for constraining mantle abundances are lunar volcanic rocks. Lunar basalts typically have very low concentrations of HSE and highly fractionated HSE patterns. Because of our extremely limited understanding of mantle melt partitioning of the HSE, even for terrestrial systems, extrapolations to mantle compositions from basaltic compositions are difficult, except possibly for the less compatible HSE Pt and Pd. Primitive, presumably less fractionated materials, such as picritic glasses are potentially more diagnostic of the lunar interior. Here we report Os isotopic composition data and Re, Os, Ir, Ru, Pt and Pd concentration data for green glass (15426,164) and orange glass (74001,1217). As with previous studies utilizing neutron activation analysis, we are examining different size fractions of the spherules to assess the role of surface condensation in the generation of the HSE abundances.

Walker, R. J.↗
NASA NTRS1973

Fracture trends identified by ERTS-1 imagery in Utah and Nevada

The author has identified the following significant results. In the Utah-Nevada area, linear structural trends recorded on ERTS-1 imagery conform in part to previously recognized structures. In addition, the ERTS-1 imagery reveals cryptic structures not previously identified and not readily apparent in other imagery. These structures are illustrated by prominent east-west trending structures which appear to be concentrated in pre-volcanic rocks. This suggests that the structures are older than many of those with other trends which are equally prominent in volcanic and non-volcanic terrain. Since the older east-west structures may have controlled early Tertiary emplacement of magma or the ascent of mineralizing fluids, their recognition is important in minerial exploration. Soil-gas sampling and analysis for mercury content is being continued over structures, and projected trends of buried structures which appear, from studies of ERTS-1 imagery, to be favorable to mineralization. Comparison of ERTS-1 and Skylab imagery indicated that ERTS-1 imagery records more previously unrecognized linear structures than the Skylab imagery. In differentiating and identifying different rock types, the Skylab imagery appears to be more effective.

Jensen, M. L.↗
NASA NTRS1985

Geologic processes on Venus: An update

Studies of Venera 15 and 16 radar image and altimetry data and reevaluation of Pioneer Venus and earlier Venera data have greatly expanded the perception of the variety and complexity of geologic processes on Venus. PV data have discriminated four highland regions (each different in geomorphic appearance), a large upland rolling plains region, and smaller areas of lowland plains. Two highland volcanic centers were identified that may be presently active, as suggested by their geomorphologic appearance combined with positive gravity anomalies, lightning strike clusters, and a change in SO2 content in the upper atmosphere. Geochemical data obtained by the Venera landers have indicated that one upland area and nearby rolling plains are composed of volcanic rocks, probably basalts or syenites. New Venera radar images of the Ishtar Terra region show folded and/or faulted linear terrain and associated volcanic features that may have been deformed by both compressional and extensional forces. Lowland surfaces resemble the mare basaltic lava flows that fill basins on the Moon, Mars and Earth. Ubiquitous crater like forms may be of either volcanic or impact origin; the origin of similar lunar features was determined by the character of their ejecta deposits.

Masursky, H.↗
NASA NTRS1983

The new airborne Thermal Infrared Multispectral Scanner (TIMS)

A new airborne Thermal Infrared Multispectral Scanner (TIMS) with six bands between 8 and 12 microns is briefly characterized, and some results of remote sensing experiments are reported. The instrument has an instantaneous field of view of 2.5 milliradians, a total field of view of 80 deg, and a NE Delta T of approximately 0.1-0.3 C depending on the band. In the TIMS image of Death Valley, silica-rich rocks were easily separable from the nonsilicates. The Eureka Quartzite stood out in sharp contrast to other Ordovician and Cambrian metasediments, and Tertiary volcanic rocks were easily separable from both. Also distinguishable were various units in the fan gravels.

Kahle, A. B.↗
NASA NTRS1975

An evaluation of Skylab (EREP) remote sensing techniques applied to investigations of crustal structure

The author has identified the following significant results. Film positives (70mm) from all six S190A multispectral photographic camera stations for any one scene can be registered and analyzed in a color additive viewer. Using a multispectral viewer, S190A and B films can be projected directly onto published geologic and topographic maps at scales as large as 1:62,500 and 1:24,000 without significant loss of detail. S190A films and prints permit the detection of faults, fractures, and other linear features not visible in any other space imagery. S192 MSS imagery can be useful for rock-type discrimination studies and delineation of linear patterns and arcuate anomalies. Anomalous color reflectances and arcuate color patterns revealed mineralized zones, copper deposits, vegetation, and volcanic rocks in various locations such as Panamint Range (CA), Greenwater (Death Valley), Lava Mountains (CA), northwestern Arizona, and Coso Hot Springs (CA).

Bechtold, I. C.↗
NASA NTRS1985

Constraints on the development of the early continental crust from isotopic data

Aspects of the origin and development of the early (AE) continential crust are addressed by radiogenic isotope and trace element studies. The most important ones are: (1) at what time did the earliest continental crust form; (2) what was its composition; (3) by what processes did it grow and by what processes was it destroyed; (4) what were the rates of production and destruction as a function of time during this time period? Nd is isotopic data on the oldest terrestrial rocks indicate that the mantle at this time had already suffered substantial depletion in incompatible elements due to earlier continent forming events. Isotopic data on young volcanic rocks derived from the depleted mantle show no evidence of this early history. The observed isotopic patterns of Nd, Sr, Hf and Pb through time together with the presently observed age spectrum of crustal rocks are considered. These patterns can be modelled by a transport model in which the continental growth and destruction rates are allowed to vary as a function of time. It is suggest that the mass of the continents at 3.8 AE ago was about 25% of the current continental mass. However, due to the very high recycling rates obtained in the early Archean only a few percent of this crust has been preserved up to the present.

Jacobson, S. B.↗
NASA NTRS1985

Magmas as Selective Filters of Volatiles Between Planetary Mantles and Surfaces

The composition of early planetary atmospheres and biospheres which is a knowledge of the relationship between mantle volatiles and volcanic gases was analyzed. In the case of Earth it appears that volcanic rocks and gases are relatively oxidized compared to the upper mantle. In the case of the C-O-H volatiles, (H2O, CO2, CO, CH4, H2) the volcanic gases are enriched in H2O and CO2 while the volatiles in the mantle may be dominated by H2O, H2 and possibly CH4. An experimental technique was perfected for phase equilibrium studies in the 5-30 kbar range which allows accurate control of volatile species activities in the fluid phase. The system was used to measure the relative solubilities of H2O, CO2, CO, CH4 and H2 in magmas at 10 kbar pressure. It is found that mantle magmas will selectively screen volatiles from planetary surfaces, forcing volcanic gases towards the neutral QFM oxidation state where H2O is the dominant species.

Holloway, J. R.↗
NASA NTRS2011

Fayalite Oxidation Processes: Experimental Evidence for the Stability of Pure Ferric Fayalite?

Olivine is one of the most important minerals in Earth and planetary sciences. Fayalite Fe2(2+)SiO4, the ferrous end-member of olivine, is present in some terrestrial rocks and primitive meteorites (CV3 chondrites). A ferric fayalite (or ferri-fayalite), Fe(2+) Fe2(3+)(SiO4)2 laihunite, has been reported in Earth samples (magnetite ore, metamorphic and volcanic rocks...) and in Martian meteorites (nakhlites). Laihunite was also synthesized at 1 atmosphere between 400 and 700 C. We show evidence for the stability of a pure ferrifayalite end-member and for potential minerals with XFe(3+) between 2/3 and 1.

Martin, A. M.↗
NASA NTRS1973

Surface configuration as an explanation for lithology-related cross-polarized radar image anomalies

One problem that has persisted since the development of multipolarized radar is the cause or causes of differential depolarization which is expressed as tonal reversals between like- and cross-polarized images of certain outcrops. Rocks producing anomalously low returns on the cross-polarized image could be classed into three general types: (1) certain geologically recent lava flows (late Pleistocene and Holocene), (2) some tertiary volcanics and (3) certain massive sandstones. Differential depolarization has been produced by volcanic rocks of various compositions including rhyolite, rhyodacite, dacite, andesite, and basalt. This has led to the conclusion that differential depolarization is not directly caused by any compositional factor. However, the study of aerial photos and subsequent field observation have led to the conclusion that the weathering and other surface characteristics of the outcrops are responsible for their appearance on multipolarized imagery.

Mccauley, J. R.↗
DOE OSTI2024

Cosmogenic 21 Ne exposure ages on late Pleistocene moraines in Lassen Volcanic National Park, California, USA

We report new cosmogenic 21 Ne in quartz exposure ages from 18 samples on three distinct moraines deposited in the Lost Creek drainage, approximately 3–7 km down-valley from Lassen Peak in Lassen Volcanic National Park. Although measuring 21 Ne in quartz is generally straightforward, accurate 21Ne exposure dating of deposits of late Pleistocene is rarely possible due to the significant quantities of non-cosmogenic 21 Ne present in most lithologies. Young quartz-bearing volcanic rocks have been observed to be an exception. We take advantage of moraine boulders sourced from the ~28 ka dacite of Lassen Peak to generate a chronology of alpine deglaciation in Lassen Volcanic National Park. Ages from three distinct moraines are in stratigraphic order at 22.1 ± 3.8, 20.2 ± 2.4, and 15.3 ± 3.8 ka and generally agree with other terminal and some recessional moraine ages across the Cascade Range and Sierra Nevada of the western United States. To date, these are among the youngest surfaces ever dated using cosmogenic 21 Ne and provide a cost-effective proof-of-concept approach to dating moraines where applicable.

58 GEOSCIENCES↗
NASA NTRS1993

Effect of subglacial volcanism on changes in the West Antarctic Ice Sheet

Rapid changes in the West Antarctic Ice Sheet (WAIS) may affect future global sea-level changes. Alley and Whillans note that 'the water responsible for separating the glacier from its bed is produced by frictional dissipation and geothermal heat,' but assume that changes in geothermal flux would ordinarily be expected to have slower effects than glaciological parameters. I suggest that episodic subglacial volcanism and geothermal heating may have significantly greater effects on the WAIS than is generally appreciated. The WAIS flows through the active, largely asiesmic West Antarctic rift system (WS), which defines the sub-sea-level bed of the glacier. Various lines of evidence summarized in Behrendt et al. (1991) indicate high heat flow and shallow asthenosphere beneath the extended, weak lithosphere underlying the WS and the WAIS. Behrendt and Cooper suggest a possible synergistic relation between Cenozoic tectonism, episodic mountain uplift and volcanism in the West Antarctic rift system, and the waxing and waning of the Antarctic ice sheet beginning about earliest Oligocene time. A few active volcanoes and late-Cenozoic volcanic rocks are exposed throughout the WS along both flanks, and geophysical data suggest their presence beneath the WAIS. No part of the rift system can be considered inactive. I propose that subglacial volcanic eruptions and ice flow across areas of locally (episodically?) high heat flow--including volcanically active areas--should be considered possibly to have a forcing effect on the thermal regime resulting in increased melting at the base of the ice streams.

Behrendt, John C.↗
NASA NTRS1973

Seismicity and recent faulting in eastern California and western and central Nevada: A preliminary report

The author has identified the following significant results. ERTS-1 imagery covering the eastern California-Nevada seismic belt were utilized to study the fault pattern in relation to the distribution of earthquake epicenters and Quaternary volcanic rocks. Many suspected faults not previously mapped were identified. These include several suspected shear zones in Nevada, faults showing evidence of recent breakage, and major lineaments. Highly seismic areas are generally characterized by Holocene faulting and Quaternary volcanic activity. However, several major fault segments showing evidence of recent breakage are associated with little or no seismicity. The tectonic pattern strongly suggests that the eastern California-Nevada seismic belt coincides with a major crustal rift associated with zones of lateral shear. New data on potentially active fault zones have direct practical applications in national and local earthquake hazard reduction programs. Positive contacts have been made with Kern and Ventura Counties to make results of this investigation available for application to their earthquake hazards definition projects.

Abdel-Gawad, M.↗
NASA NTRSDate not supplied

The Chemistry and Mineralogy of Mars Soils: A Tour of Landed Mission Results from the Last 45 years

Eight landed missions demonstrated that martian soils (defined as loose, unconsolidated surface material) consist of basaltic mineralogy, iron (hydr)oxides, amorphous material, sulfate, chloride, (per)chlorate, nitrate, carbonate, and possible organic C. The Viking Lander 1 and 2 (1976), Mars Pathfinder (1997), and Mars Exploration Rover (MER-A,B) (2004) missions determined that martian soil was similar at all landing sites by having mafic chemistry, high S (~ 7 wt.% SO3) and Cl (0.7 wt.%), and spectral detections of poorly crystalline and crystalline Fe-(hydr)oxide phases. The MER Mössbauer spectrometers detected Fe-bearing olivine and pyroxene along with magnetite, nano-phase Fe-oxides (npOx), hematite, and ferric sulfate. The 2008 Phoenix Lander instrumentation measured a soil pH of 7.7 and detected ~0.6 wt.% perchlorate, 3-5 wt.% Ca-rich carbonate and carbon (500 gC/g) consistent with oxidized organics and Fe-rich carbonate. The 2012 Mars Science Laboratory (MSL) rover (Gale Crater) through X-ray diffraction detected plagioclase feldspar, pyroxene, magnetite, hematite, anhydrite, and quartz, with the balance being composed of Si/Fe-containing amorphous (30 to 40 wt.%) material. MSL evolved gas analysis detected (per)chlorate (0.4 wt.% ClO4), nitrate (0.23 wt.%), along with minor Fe/Mg sulfate and oxidized organic C (~2000 gC/g). Limited pedogenesis may have occurred at the 2018 InSight landing site and in one Gusev Crater soil (MER-B) which have 3 to 10 cm-thick duricrust horizons consistent with atmospheric water vapor interactions with soil salts. Martian soil primary mineralogy was derived mostly from local rock (volcanic, sedimentary) that is largely basaltic planet wide. Secondary minerals [e.g., sulfate, chloride, perchlorate, nitrate, carbonate, Fe-(hydr)oxides] in martian soils formed from oxidative aqueous alteration processes and were likely derived from a combination of local sedimentary rock sources and the global bright dust. The Mars 2020 mission will collect soil for Earth return to enable a thorough assessment of the nature and origin of martian soil.

Mars↗
NASA NTRS1988

Mars: Volcanism in the Valles Marineris overlooked

Do volcanic rocks exist in the Valles Marineris. This question is pertinent because the Valles Marineris are gigantic grabens, rivaling rift valleys on earth in size and depth. The Valles Marineris were interpreted as extensional tectonic structures, perhaps incipient rifts. On earth, rift valleys commonly contain volcanic deposits. On Mars, deposits inside the Valles Marineris grabens do not have the morphologic signature of such easily identified volcanic features as shield volcanoes or lava flows. Therefore, many researchers have not recognized the deposits inside the Valles Marineris as volcanic. Is Mars, then, different from earth in having formed riftlike grabens unaccompanied by volcanism. Overall, results from the study suggest that volcanism was present in the Valles Marineris; the volcanism was explosive in places; some volcanism was more felsic than that generally assumed elsewhere; and the younger sequence of interior beds was emplaced so late in Martian history that the planet may be considered to be still volcanically active.

Lucchitta, B. K.↗