Carbonaceous matter in peridotites and basalts studied by XPS, SALI, and LEED

Tingle, Tracy N.; Mathez, E. A.; Michael, F.Hochella

doi:10.1016/0016-7037(91)90312-s

Cited by 55 publications

(39 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the fragments containing these carbonaceous films occurred in areas with a high density of cracks and imperfections. Since these films are likely to be > 100 • thick and of terrestrial origin [Tingle et al, 1990[Tingle et al, , 1991, we believe that these surfaces are not representative of pristine olivine, and thus we eliminated them from our study.…”

Section: Introductionmentioning

confidence: 99%

Surface modification of olivine by H⁺ and He⁺ bombardment

Dukes¹,

Baragiola²,

McFadden³

1999

J. Geophys. Res.

112

View full text Add to dashboard Cite

Abstract. Laboratory simulations of solar wind irradiation of olivine, a constituent of ordinary chondritic meteorites and S-type asteroids, show a dramatic chemical reduction of surface iron and, to a lesser extent, silicon. Earth's atmosphere oxidizes any reduced iron instantaneously, whereas irradiated material on the surface of an asteroid would remain reduced. Changes in optical reflectance, due to metallization of the surface, provide a possible explanation for differences in the near-infrared spectra of ordinary chondrite meteorites and their likely parent bodies, the S(IV) asteroids. IntroductionIn an equilibrium condensation model of the formation of the solar system [Grossman, 1972], the mineral phases present in ordinary chondrite meteorites, olivine, pyroxene, plagioclase, and metallic iron, are formed at primordial temperatures consistent with the inner edge of the asteroid belt; therefore one might expect to find ordinary chondritic parent bodies within this region. However, the spectral reflectance of S-type asteroids has a redder slope and weaker 1.

show abstract

Section: Introductionmentioning

confidence: 99%

Surface modification of olivine by H⁺ and He⁺ bombardment

Dukes¹,

Baragiola²,

McFadden³

1999

J. Geophys. Res.

112

View full text Add to dashboard Cite

show abstract

“…Such factors are essential to the understanding of electrical conductivity measurements made on deep crustal materials (Duba and Shankland, 1982;Frost and others, 1989;Mathez and others, 1995;Yardley and Valley, 1997). The fluid-deposition and -resorp tion of graphite also control the mobility of carbon in the crust and mantle, as well as the "stability" (longevity) of carbon films (Mathez, 1987;Tingle, Mathez, and Hochella, 1991;Sugisaki and Mimura, 1994). Larger-scale deposition of graphite, particularly in granulite terranes, drew attention to the possibility of regional infiltration by large volumes of CO2 and to the oxygen fugacities necessary to stabilize graphite under those metamorphic conditions (Newton, Smith, and Windley, 1980;Glassley, 1982;Lamb and Valley, 1984;Katz, 1987;Dissanayake, 1994).…”

Section: Fj Luque and Others-natural Fluid-deposited Graphitementioning

confidence: 99%

Natural fluid-deposited graphite; mineralogical characteristics and mechanisms of formation

Luque¹,

Pasteris²,

Wopenka³

et al. 1998

American Journal of Science

235

186

View full text Add to dashboard Cite

ABSTRACT. This paper focuses on the similarities and diff erences between meta morphic graphite (formed in situ from organic matter) and fluid-deposited graph ite. We discuss the formation of fluid-deposited graphite in terms of the source of carbon, the characteristics of the C-bearing fluids (the C-O-H system), the mecha nisms of carbon mobilization, and the mechanisms of carbon precipitation. New and existin � analytical data are compiled on the physical and chemical character istics of fluId-deposited graphite olitained by the following techniques: optical microscopy, diff erential ilierrilal analysis, thermogravimetry, X-ray diffraction, Ra man spectroscopy, and stable isotope mass spectrometry. Our discussions focus on major, that is, volumetrically significant, worldwide concentrations of graphite.

show abstract

“…SOLID SOLUTIONS WITH CO 2 Any oxide and silicate crystallizing in the presence of CO 2 must also take up a small amount of CO 2 into solid solution. Some in the geoscience community reject outright the notion that carbon enters into the structure of oxides or silicates (Keppler et al 2003;Mathez et al 1987;Tingle et al 1991;Tsong et al 1985). This view is inconsistent with thermodynamics and solid-state principles.…”

Section: A2 Solid Solutions With H 2 Omentioning

confidence: 99%

Solid Solution Model for Interstellar Dust Grains and Their Organics

Freund

2006

ApJ

View full text Add to dashboard Cite

We present a dust grain model based on the fundamental principle of solid solutions. The model is applicable to the mineral (silicate) component of the dust in the interstellar medium (ISM ). We show that nanometer-sized mineral grains, which condense in the gas-rich outflow of late-stage stars or expanding gas shells of supernova explosions, do not consist of just high melting point oxides or silicates. Instead they form solid solutions with gas-phase components H 2 O, CO, and CO 2 that are omnipresent in environments where the grains condense. Through a series of thermodynamically well-understood solid-state processes, these solid solutions become ''parents'' of organic matter that precipitates inside the grains. Thus, the mineral dust grains and their organics become part of the same thermodynamically defined solid phase and, hence, physically inseparable. This model can account for many astronomical observations, which no prior model can adequately address, specifically: (1) Organics in the diffuse ISM are identified by a 3.4 m IR band, characteristic of aliphatic hydrocarbons composed of ÀCH 2 À and of ÀCH 3 groups. (2) The methylene-to-methyl ratio is nearly constant, implying a CH 2 :CH 3 ratio of $5:2. (3) The intensity ratio between the 9.7 and the 3.4 m band is nearly constant, implying a silicate-to-organics ratio of $10:1. (4) In dense clouds the complex 3.4 m band is replaced by a weak, featureless 3.47 m band. (5) Whereas silicate grains identified by their 9.7 m band tend to align in magnetic fields, grains with a strong 3.4 m organic signature do not tend to align.

show abstract

Carbonaceous matter in peridotites and basalts studied by XPS, SALI, and LEED

Cited by 55 publications

References 26 publications

Surface modification of olivine by H⁺ and He⁺ bombardment

Surface modification of olivine by H⁺ and He⁺ bombardment

Natural fluid-deposited graphite; mineralogical characteristics and mechanisms of formation

Solid Solution Model for Interstellar Dust Grains and Their Organics

Contact Info

Product

Resources

About

Carbonaceous matter in peridotites and basalts studied by XPS, SALI, and LEED

Cited by 55 publications

References 26 publications

Surface modification of olivine by H+ and He+ bombardment

Surface modification of olivine by H+ and He+ bombardment

Natural fluid-deposited graphite; mineralogical characteristics and mechanisms of formation

Solid Solution Model for Interstellar Dust Grains and Their Organics

Contact Info

Product

Resources

About

Surface modification of olivine by H⁺ and He⁺ bombardment

Surface modification of olivine by H⁺ and He⁺ bombardment