ABOUT THIS COLLECTION

Meteoritics & Planetary Science is an international monthly journal of the Meteoritical Society—a scholarly organization promoting research and education in planetary science. Topics include the origin and history of the solar system, planets and natural satellites, interplanetary dust and interstellar medium, lunar samples, meteors and meteorites, asteroids, comets, craters, and tektites.

Meteoritics & Planetary Science was first published in 1935 under the title Contributions of the Society for Research on Meteorites. In 1947, the publication became known as Contributions of the Meteoritical Society and continued through 1951. From 1953 to 1995, the publication was known as Meteoritics, and in 1996, the journal's name was changed to Meteoritics & Planetary Science or MAPS. The journal was not published in 1952 and from 1957 to 1964.

This archive provides access to Meteoritics & Planetary Science Volumes 37-44 (2002-2009).

Visit Wiley Online Library for new and retrospective Meteoritics & Planetary Science content (1935-present).

ISSN: 1086-9379

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Recent Submissions

  • Evidence for ocean water invasion into the Chicxulub crater at the Cretaceous/Tertiary boundary

    Goto, K.; Tada, R.; Tajika, E.; Bralower, T. J.; Hasegawa, T.; Matsui, T. (The Meteoritical Society, 2004-01-01)
    The possibility of ocean water invasion into the Chicxulub crater following the impact at the Cretaceous/Tertiary boundary was investigated based on examination of an impactite between approximately 794.63 and 894.94 m in the Yaxcopoil‐1 (Yax‐1) core. The presence of cross lamination in the uppermost part of the impactite suggests the influence of an ocean current at least during the sedimentation of this interval. Abundant occurrence of nannofossils of late Campanian to early Maastrichtian age in the matrices of samples from the upper part of the impactite suggests that the carbonate sediments deposited on the inner rim margin and outside the crater were eroded and transported into the crater most likely by ocean water that invaded the crater after its formation. The maximum grain size of limestone lithics and vesicular melt fragments, and grain and bulk chemical compositions show a cyclic variation in the upper part of the impactite. The upward fining grain size and the absence of erosional contact at the base of each cycle suggest that the sediments were derived from resuspension of units elsewhere in the crater, most likely by high energy currents association with ocean water invasion.
  • Oxygen isotopic alteration in Ca‐Al‐rich inclusions from Efremovka: Nebular or parent body setting?

    Fagan, T. J.; Krot, A. N.; Keil, K.; Yurimoto, H. (The Meteoritical Society, 2004-01-01)
    In situ SIMS oxygen isotope data were collected from a coarse‐grained type B1 Ca‐Al‐rich inclusion (CAI) and an adjacent fine‐grained CAI in the reduced CV3 Efremovka to evaluate the timing of isotopic alteration of these two objects. The coarse‐grained CAI (CGI‐10) is a sub‐spherical object composed of elongate, euhedral, normally‐zoned melilite crystals ranging up to several hundreds of Pm in length, coarse‐grained anorthite and Al, Ti‐diopside (fassaite), all with finegrained (∼10 μm across) inclusions of spinel. Similar to many previously examined coarse‐grained CAIs from CV chondrites, spinel and fassaite are 16O‐rich and melilite is 16O‐poor, but in contrast to many previous results, anorthite is 16O‐rich. Isotopic composition does not vary with textural setting in the CAI: analyses of melilite from the core and mantle and analyses from a variety of major element compositions yield consistent 16O‐poor compositions. CGI‐10 originated in an 16O‐rich environment, and subsequent alteration resulted in complete isotopic exchange in melilite. The fine‐grained CAI (FGI‐12) also preserves evidence of a 1st‐generation origin in an 16O‐rich setting but underwent less severe isotopic alteration. FGI‐12 is composed of spinel ± melilite nodules linked by a mass of Al‐diopside and minor forsterite along the CAI rim. All minerals are very fine‐grained (<5 μm) with no apparent igneous textures or zoning. Spinel, Al‐diopside, and forsterite are 16O‐rich, while melilite is variably depleted in 16O (δ17,18O from ∼‐40‰ to −5‰). The contrast in isotopic distributions in CGI‐10 and FGI‐12 is opposite to the pattern that would result from simultaneous alteration: the object with finer‐grained melilite and a greater surface area/ volume has undergone less isotopic exchange than the coarser‐grained object. Thus, the two CAIs were altered in different settings. As the CAIs are adjacent to each other in the meteorite, isotopic exchange in CGI‐10 must have preceded incorporation of this CAI in the Efremovka parent body. This supports a nebular setting for isotopic alteration of the commonly observed 16O‐poor melilite in coarse‐grained CAIs from CV chondrites.
  • Book Review: Visions of the Cosmos, Carolyn Collins Petersen, John C. Brandt

    Mueller, B. E. A. (The Meteoritical Society, 2004-01-01)
  • Robert M. Walker, 1929-2004

    Floss, C.; Sandford, S.; Zinner, E. (The Meteoritical Society, 2004-01-01)
  • Note

    Short, N. M. (The Meteoritical Society, 2004-01-01)
  • I-Xe measurements of CAIs and chondrules from the CV3 chondrites Mokoia and Vigarano

    Whitby, J. A.; Russell, S. S.; Turner, G.; Gilmour, J. D. (The Meteoritical Society, 2004-01-01)
    I-Xe analyses were carried out for chondrules and refractory inclusions from the two CV3 carbonaceous chondrites Mokoia and Vigarano (representing the oxidized and reduced subgroups, respectively). Although some degree of disturbance to the I-Xe system is evident in all of the samples, evidence is preserved of aqueous alteration of CAIs in Mokoia 1 Myr later than the I-Xe age of the Shallowater standard and of the alteration of a chondrule (V3) from Vigarano ~0.7 Myr later than Shallowater. Other chondrules in Mokoia and Vigarano experienced disturbance of the I-Xe system millions of years later and, in the case of one Vigarano chondrule (VS1), complete resetting of the I-Xe system after decay of essentially all 129I, corresponding to an age more than 80 Myr after Shallowater. Our interpretation is that accretion and processing to form the Mokoia and Vigarano parent bodies must have continued for at least 4 Myr and 80 Myr, respectively. The late age of a chondrule that shows no evidence for any aqueous alteration or significant thermal processing after its formation leads us to postulate the existence of an energetic chondrule-forming mechanism at a time when nebular processes are not expected to be important.
  • Aerogel keystones: Extraction of complete hypervelocity impact events from aerogel collectors

    Westphal, Andrew J.; Snead, Christopher; Butterworth, Anna; Graham, Giles A.; Bradley, John P.; Bajt, Sasa; Grant, Patrick G.; Bench, Graham; Brennan, Sean; Pianetta, Piero (The Meteoritical Society, 2004-01-01)
    In January 2006, the Stardust mission will return the first samples from a solid solar system body beyond the Moon and the first samples of contemporary interstellar dust ever collected. Although sophisticated laboratory instruments exist for the analysis of Stardust samples, techniques for the recovery of particles and particle residues from aerogel collectors remain primitive. Here, we describe our recent progress in developing techniques for extracting small volumes of aerogel, which we have called "keystones," which completely contain particle impacts but minimize the damage to the surrounding aerogel collector. These keystones can be fixed to custom-designed micromachined silicon fixtures (so called "microforklifts"). In this configuration, the samples are self-supporting, which can be advantageous in situations where interference from a supporting substrate is undesirable. The keystones may also be extracted and placed onto a substrate without a fixture. We have also demonstrated the capability of homologously crushing these unmounted keystones for analysis techniques that demand flat samples.
  • Thuathe, a new H4/5 chondrite from Lesotho: History of the fall, petrography, and geochemistry

    Reimold, W. U.; Buchanan, P. C.; Ambrose, D.; Koeberl, C.; Franchi, I.; Lalkhan, C.; Schultz, L.; Franke, L.; Heusser, G. (The Meteoritical Society, 2004-01-01)
    On July 21, 2002, a meteorite fall occurred over the Thuathe plateau of western Lesotho. The well-defined strewn field covers an area of 1.9 x 7.4 km. Many of the recovered specimens display a brecciated texture with leucocratic, angular to subrounded clasts in a somewhat darker groundmass. Mineralogical and chemical data, as well as oxygen isotopic analysis, indicate that Thuathe is an H4/ 5, S2/3 meteorite, with local H3 or H6 character. A number of anomalous features include somewhat high Co contents of kamacite and taenite relative to normal H-group chondrites. Oxygen isotopic data plot at the edge of the normal H chondrite data field. Variable contents of metallic mineral phases and troilite result in a heterogeneous bulk composition (e.g., with regard to Si, Fe, and Mg), resulting in a spread of major element ratios that is not consistent with previously accepted H-group composition. Trace element abundances are generally consistent with H chondritic composition, and Kr and Xe isotopic data agree with an H4 classification for this meteorite. Noble gas analysis gave U, Th-4He gas retention and K-Ar ages typical for H chondrites; no major thermal event affected this material since ~3.7 Ga. The exposure age for Thuathe is 5 Ma, somewhat lower than for other H chondrites. Cosmogenic nuclide analysis indicates a pre-atmospheric radius of this meteorite between 35 and 40 cm. In the absence of evidence for solar gases, we classify Thuathe as a fragmental breccia. Numerous narrow, black veins cut across samples of Thuathe and are the result of a brittle deformation event that also caused local melting, especially in portions rich in sulfide. The formation of these veinlets is not the result of locally enhanced shock pressures (i.e., of shock melting) but rather of shearing under brittle conditions with local, friction-related temperature excursions causing melting mostly of Fe-sulfide and FeNi-metal but also, locally, of silicate minerals. Frictional temperature excursions must have attained values in excess of 1500 degrees C to permit complete melting of forsteritic olivine.
  • High-calcium pyroxene as an indicator of igneous differentiation in asteroids and meteorites

    Sunshine, Jessica M.; Bus, Schelte J.; McCoy, Timothy J.; Burbine, Thomas H.; Corrigan, Catherine M.; Binzel, Richard P. (The Meteoritical Society, 2004-01-01)
    Our analyses of high quality spectra of several S-type asteroids (17 Thetis, 847 Agnia, 808 Merxia, and members of the Agnia and Merxia families) reveal that they include both low- and highcalcium pyroxene with minor amounts of olivine (<20%). In addition, we find that these asteroids have ratios of high-calcium pyroxene to total pyroxene of >~0.4. High-calcium pyroxene is a spectrally detectable and petrologically important indicator of igneous history and may prove critical in future studies aimed at understanding the history of asteroidal bodies. The silicate mineralogy inferred for Thetis and the Merxia and Agnia family members requires that these asteroids experienced igneous differentiation, producing broadly basaltic surface lithologies. Together with 4 Vesta (and its smaller "Vestoid" family members) and the main-belt asteroid 1489 Magnya, these new asteroids provide strong evidence for igneous differentiation of at least five asteroid parent bodies. Based on this analysis of a small subset of the near-infrared asteroid spectra taken to date with SpeX at the NASA IRTF, we expect that the number of known differentiated asteroids will increase, consistent with the large number of parent bodies inferred from studies of iron meteorites.
  • Sodium-metasomatism in chondrules in CO3 chondrites: Relationship to parent body thermal metamorphism

    Tomeoka, Kazushige; Itoh, Daisuke (The Meteoritical Society, 2004-01-01)
    We have studied the mineralogy and petrology of mesostases of 783 type I chondrules in seven CO3 chondrites that range in petrologic subtype from 3.0 to 3.7. Chondrule mesostases in the CO chondrite of subtype 3.0 consist mainly of primary glass and plagioclase, while chondrule mesostases in the CO chondrites of higher subtypes (3.2-3.7) contain various amounts of nepheline in addition to glass and plagioclase. Nepheline has replaced glass and plagioclase, forming finegrained aggregates and thin parallel lamellar intergrowths with plagioclase. The nephelinization has proceeded preferentially from the outer margins of chondrules toward the inside. Although the degree of nephelinization differs widely among chondrules in each of the metamorphosed chondrites, our modal analyses and bulk chemical analyses of individual mesostases indicate that the amounts of nepheline in chondrules systematically increase with the increasing petrologic subtype of the host chondrites. Nepheline also has a tendency to increase in grain size with increasing petrologic subtype. We conclude that nepheline in chondrules in the CO3 chondrites has formed largely as a result of effects related to heating on the meteorite parent body. We suggest that nepheline initially formed as hydrous nepheline under the presence of aqueous fluids and subsequently was dehydrated after exhaustion of aqueous fluids. The degree of hydrothermal activity must have increased with increasing degree of heating, and thus, chondrules in more thermally metamorphosed chondrites produced larger amounts of nepheline. The results imply that CO3 chondrites have gone through lowgrade aqueous alteration and subsequent dehydration at the early stage of heating on the meteorite parent body.
  • The activity of chromite in multicomponent spinels: Implications for T-fO2 conditions of equilibrated H chondrites

    Kessel, Ronit; Beckett, John R.; Huss, Gary R.; Stolper, Edward M. (The Meteoritical Society, 2004-01-01)
    Activities of chromite in multicomponent spinels with compositions similar to those of H chondrites were experimentally determined by equilibrating Pt-alloys with spinel at known temperature and fO2. Our results are consistent with predictions based on the spinel solid solution model incorporated into the MELTS program. Therefore, we combined literature formulations for the activities of components in spinel, the ferromagnesian silicates, and alloys with measured and literature (bulk alloy) compositions of the meteoritic phases to constrain T-fO2 conditions for the Hgroup chondrites Avanhandava (H4), Allegan (H5), and Guarea (H6). Log10fO2 values based on the assemblage of olivine + orthopyroxene + metal are 2.19-2.56 log units below the iron-wstite (IW) buffer for any equilibration temperature between 740 and 990 degrees C, regardless of petrographic type. Only lower limits on fO2 could be determined from spinel + metal equilibria because of the extremely low concentrations of Cr in the alloys of equilibrated H chondrites (3 ppb). Log10fO2 values required by spinel + metal equilibria are inconsistent with those for olivine + orthopyroxene + metal if equilibration temperatures were at or above those inferred from olivine-spinel thermometry. This probably indicates that the closure for spinel + metal equilibria occurred under retrograde conditions at temperatures below ~625 degrees C for Allegan and Guarea and below ~660 degrees C for Avanhandava.
  • Formation of accretionary dust mantles in the solar nebula: Evidence from preirradiated olivines in CM chondrites

    Metzler, Knut (The Meteoritical Society, 2004-01-01)
    CM chondrites are regolith breccias consisting of lithic clasts embedded in a fine-grained clastic matrix. The majority of these lithic clasts belongs to a texturally well-defined rock type (primary rock) that can be described as an agglomerate of chondrules and other coarse-grained components, most of which are surrounded by fine-grained rims (dust mantles). Metzler et al. (1992) explain these textures as the result of accretionary processes in the solar nebula, while an alternative model explains them to be the result of regolith processes on the parent body (Sears et al. 1993). The main intention of the present study is to discern between both models by investigating the occurrence, frequency, spatial distribution, and textural setting of preirradiated (track-rich) olivines in CM chondrites. Track-rich olivines were studied in situ in six polished thin sections from 4 different CM chondrites (Cold Bokkeveld, Mighei, Murchison, Nogoya) by optical and scanning electron microscopy (SEM). It was found that their occurrence is restricted to the clastic matrix of these meteorites. The primary rock seems to have formed in an environment shielded from cosmic radiation, since fragments of this rock are free of track-rich grains and solar noble gases. This finding supports the solar nebula model for the formation of dust mantles around chondrules and other coarse-grained components, and points against a regolith origin. In Cold Bokkeveld, a small breccia-in-breccia clast was found, which has been irradiated as an entity within the uppermost millimeters to meters of its parent body for at least about 3 Ma. This clast seems to represent a compacted subsurface layer that was later excavated by impact and admixed to the host breccia. Furthermore, the results of this study may affect the interpretation of compaction ages obtained by fission track methods, since these ages may be mixtures of different contact ages between finegrained, U-rich dust and U-poor olivines. In some cases, they may date the formation of dust mantles in the solar nebula, while in other cases the lithification of the host breccias may be dated.
  • Discovery of Earth's quasi-satellite

    Connors, Martin; Veillet, Christian; Brasser, Ramon; Wiegert, Paul; Chodas, Paul; Mikkola, Seppo; Innanen, Kimmo (The Meteoritical Society, 2004-01-01)
    The newly discovered asteroid 2003 YN107 is currently a quasi-satellite of the Earth, making a satellite-like orbit of high inclination with apparent period of one year. The term quasisatellite is used since these large orbits are not completely closed, but rather perturbed portions of the asteroid's orbit around the Sun. Due to its extremely Earth-like orbit, this asteroid is influenced by Earth's gravity to remain within 0.1 AU of the Earth for approximately 10 years (1997 to 2006). Prior to this, it had been on a horseshoe orbit closely following Earth's orbit for several hundred years. It will re-enter such an orbit, and make one final libration of 123 years, after which it will have a close interaction with the Earth and transition to a circulating orbit. Chaotic effects limit our ability to determine the origin or fate of this object.
  • Infrared, Raman, and cathodoluminescence studies of impact glasses

    Gucsik, Arnold; Koeberl, Christian; Brandstätter, Franz; Libowitzky, Eugen; Zhang, Ming (The Meteoritical Society, 2004-01-01)
    We studied the infrared reflectance (IR), Raman, and cathodoluminescence (CL) spectroscopic signatures and scanning electron microscope-cathodoluminescence (SEM-CL) images of three different types of impact glasses: Aouelloul impact glass, a Muong Nong-type tektite, and Libyan desert glass. Both backscattered electron (BSE) and CL images of the Muong Nong-type tektite are featureless; the BSE image of the Libyan desert glass shows only weak brightness contrasts. For the Aouelloul glass, both BSE and CL images show distinct brightness contrast, and the CL images for the Libyan desert glass show spectacular flow textures that are not visible in any other microscopic method. Compositional data show that the SiO2 composition is relatively higher and the Al2O3 content is lower in the CL-bright areas than in the CL-dark regions. The different appearance of the three glass types in the CL images indicates different peak temperatures during glass formation: the tektite was subjected to the highest temperature, and the Aouelloul impact glass experienced a relatively low formation temperature, while the Libyan desert glass preserves a flow texture that is only visible in the CL images, indicating a medium temperature. All IR reflectance spectra show a major band at around 1040 to 1110 cm^(-1) (antisymmetric stretching of SiO4 tetrahedra), with minor peaks between 745 and 769 cm^(-1) (Si-O-Si angle deformation). Broad bands at 491 and 821 cm^(-1) in the Raman spectra in all samples are most likely related to diaplectic glass remnants, indicating early shock amorphization followed by thermal amorphization. The combination of these spectroscopic methods allows us to deduce information about the peak formation temperature of the glass, and the CL images, in particular, show glass flow textures that are not preserved in other more conventional petrographic images.