From Wikipedia, the free encyclopedia
  (Redirected from Micrometeorites)
Jump to: navigation, search
Micrometerorite collected from the antarctic snow.

A micrometeorite is an extraterrestrial particle, ranging in size from 50 µm to 2 mm, collected on the Earth's surface. Micrometeorites are micrometeoroids which have survived entry through the Earth's atmosphere. They differ from meteorites in being smaller, more plentiful and different in composition and are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).[1] Micrometeorites enter the Earth's atmosphere with high velocities (at least 11 km/s) and undergo heating through atmospheric friction and compression. Individual micrometeorites weigh between 10−9 and 10−4 g and collectively contribute most of the extraterrestrial material that has come to the present day Earth.[2] Fred Lawrence Whipple first coined the term "micro-meteorite" to describe dust-sized objects that fall to the Earth.[3] Sometimes meteoroids and micrometeoroids entering the Earth's atmosphere are visible as meteors or "shooting stars", whether or not they reach the ground and survive as meteorites and micrometorites.


Micrometeorite (MM) textures vary as their original structural and mineral compositions are modified by the degree of heating that they experience entering the atmosphere—a function of their initial speed and angle of entry. They range from unmelted particles that retain their original mineralogy (Fig. 1 a, b), to partially melted particles (Fig. 1 c, d) to round melted cosmic spherules (Fig. 1 e, f, g, h, Fig. 2) some of which have lost a large portion of their mass through vaporization (Fig. 1 i). Classification is based on composition and degree of heating.[4][5]

Figure 1. Cross sections of different micrometeorite classes: a) Fine-grained unmelted; b) Coarse-grained Unmelted; c) Scoriaceous; d) Relict-grain Bearing; e) Porphyritic; f) Barred olivine; g) Cryptocrystalline; h) Glass; i) CAT; j) G-type; k) I-type; and l) Single mineral. Except for G- and I-types all are silicate rich, called stony MMs. Scale bars are 50µm.
Figure 2. Light microscope images of stony cosmic spherules.

The extraterrestrial origins of micrometeorites are determined by microanalyses that show that:

  • The metal they contain is similar to that found in meteorites.[6]
  • Some have wüstite, a high-temperature iron oxide found in meteorite fusion crusts.[7]
  • Their silicate minerals have major and trace elements ratios similar to those in meteorites.[8][9]
  • The abundances of cosmogenic manganese (53Mn) in iron spherules and of cosmogenic beryllium (10Be), aluminum (26Al), and solar neon isotope in stony MMs are extraterrestrial[10][11]
  • The presence of pre-solar grains in some MMs[12] and deuterium excesses in ultra-carbonaceous MMs[13] indicates that they are not only extraterrestrial but that some of their components formed before our solar system.

An estimated 30,000 ± 20,000 tonnes per year (t/yr)[2] of cosmic dust enters the upper atmosphere each year of which less than 10% (2700 ± 1400 t/yr) is estimated to reach the surface as particles.[14] Therefore, the mass of micrometeorites deposited is roughly 50 times higher than that estimated for meteorites, which represent approximately 50 t/yr,[15] and the huge number of particles entering the atmosphere each year (~1017 > 10 µm) suggests that large MM collections contain particles from all dust producing objects in the Solar System including asteroids, comets, and fragments from our Moon and Mars. Large MM collections provide information on the size, composition, atmospheric heating effects and types of materials accreting on Earth while detailed studies of individual MMs give insights into their origin, the nature of the carbon, amino acids and pre-solar grains they contain.[16]

Collection sites[edit]

Micrometeorites have been collected from deep-sea sediments, sedimentary rocks and polar sediments; they are currently collected primarily from polar snow and ice. Because of their low concentrations on the Earth's surface, MMs are sought in environments that concentrate these materials relative to terrestrial particles.

Ocean sediments[edit]

Melted micrometeorites (cosmic spherules) were first collected from deep-sea sediments during the 1873 to 1876 expedition of the HMS Challenger. In 1891, Murray and Renard found "two groups [of micrometeorites]: first, black magnetic spherules, with or without a metallic nucleus; second, brown-coloured spherules resembling chondr(ul)es, with a crystalline structure".[17] In 1883, they suggested that these spherules were extraterrestrial because they were found far from terrestrial particle sources, they did not resemble magnetic spheres produced in furnaces of the time, and their nickel-iron (Fe-Ni) metal cores did not resemble metallic iron found in volcanic rocks. The spherules were most abundant in slowly accumulating sediments, particularly red clays deposited below the carbonate compensation depth, a finding that supported a meteoritic origin.[18] In addition to those spheres with Fe-Ni metal cores, some spherules larger than 300 µm contain a core of elements from the platinum group.[19]

Since the first collection of the HMS Challenger, cosmic spherules have been recovered from ocean sediments using cores, box cores, clamshell grabbers, and magnetic sleds.[20] Among these a magnetic sled, called the "Cosmic Muck Rake", retrieved thousands of cosmic spherules from the top 10 cm of red clays on the Pacific Ocean floor.[21]

Terrestrial sediments[edit]

Terrestrial sediments also contain micrometeorites. These have been found in samples that:

The oldest MMs are totally altered iron spherules found in 140- to 180-million-year-old hardgrounds.[23]

Amateur collectors may find micrometeorites in areas where dirt and dust from a large area has been concentrated, such as from a roof downspout.[28]

Polar depositions[edit]

Click here to see a seven-minute movie of MMs being collected from the bottom of the South Pole drinking water well.

Micrometeorites found in polar sediments are much less weathered than those found in other terrestrial environments, as evidenced by little etching of interstitial glass, and the presence of large numbers of glass spherules and unmelted micrometeorites, particle types that are rare or absent in deep-sea samples.[4] The MMs found in polar regions have been collected from Greenland snow,[29] Greenland cryoconite,[30][31][32] Antarctic blue ice[33] Antarctic aeolian (wind-driven) debris,[34][35][36] ice cores,[37] the bottom of the South Pole water well,[4][14] Antarctic sediment traps[38] and present day Antarctic snow.[13]

Classification and origins of micrometeorites[edit]


Modern classification of meteorites and micrometeorites is complex; the 2007 review paper of Krot et al.[39] summarizes modern meteorite taxonomy. Linking individual micrometeorites to meteorite classification groups requires a comparison of their elemental, isotopic and textural characteristics.[40]

Comet vs asteroid origin of micrometeorites[edit]

Whereas most meteorites likely originate from asteroids, the contrasting makeup of micrometeorites suggests that most originate from comets.

Fewer than 1% of MMs are achondritic and are similar to HED meteorites, which are thought to be from the asteroid, 4 Vesta.[41][42] Most MMs are compositionally similar to carbonaceous chondrites,[43][44][45] whereas approximately 3% of meteorites are of this type.[46] The dominance of carbonaceous chondrite-like MMs and their low abundance in meteorite collections suggests that most MMs derive from sources different than those for most meteorites. Since most meteorites probably derive from asteroids, an alternative source for MMs might be comets. The idea that MMs might originate from comets originated in 1950.[3]

Until recently the greater-than-25-km/s entry velocities of micrometeoroids, measured for particles from comet streams, cast doubts against their survival as MMs.[10][47] However, recent dynamical simulations[48] suggest that 85% of cosmic dust could be cometary. Furthermore, analyses of particles returned from the comet, Wild 2, by the Stardust spacecraft show that these particles have compositions that are consistent with many micrometeorites.[49][50] Nonetheless, some parent bodies of micrometeorites appear to be asteroids with chondrule-bearing carbonaceous chondrites.[51]

Extraterrestrial micrometeorites[edit]

The influx of micrometeoroids also contributes to the composition of regolith (planetary/lunar soil) on other bodies in the Solar System. Mars has an estimated annual micrometeoroid influx of between 2,700 and 59,000 t/yr. This contributes about 1 m of micrometeoritic content to the depth of the martian regolith each billion years. Measurements from the Viking program indicate that the martian regolith is a mixture of 60% basaltic rock and 40% of meteoritic origin. The lower-density martian atmosphere allows much larger particles than on Earth to survive the passage through to the surface, largely unaltered until impact. Whereas on Earth particles that survive entry typically have undergone significant transformation, a significant fraction of particles entering the martian atmosphere throughout the 60 to 1200-μm diameter range probably survive unmelted.[52]

See also[edit]


  1. ^ Brownlee, D. E.; Bates, B.; Schramm, L. (1997), "The elemental composition of stony cosmic spherules", Meteoritics and Planetary Science, 32 (2): 157–175, Bibcode:1997M&PS...32..157B, doi:10.1111/j.1945-5100.1997.tb01257.x 
  2. ^ a b Love, S. G.; Brownlee, D. E. (1993), "A direct measurement of the terrestrial mass accretion rate of cosmic dust", Science, 262 (5133): 550–553, Bibcode:1993Sci...262..550L, doi:10.1126/science.262.5133.550, PMID 17733236 
  3. ^ a b Whipple, Fred (1950), "The Theory of Micro-Meteorites", Proceedings of the National Academy of Sciences, 36 (12): 687–695, Bibcode:1950PNAS...36..687W, doi:10.1073/pnas.36.12.687, PMC 1063272free to read, PMID 16578350 
  4. ^ a b c Taylor, S.; Lever, J. H.; Harvey, R. P. (2000), "Numbers, Types and Compositions of an Unbiased Collection of Cosmic Spherules", Meteoritics & Planetary Science, 35 (4): 651–666, Bibcode:2000M&PS...35..651T, doi:10.1111/j.1945-5100.2000.tb01450.x 
  5. ^ Genge, M. J.; Engrand, C.; Gounelle, M.; Taylor, S. (2008), "The Classification of Micrometeorites", Meteoritics and Planetary Sciences, 43 (3): 497–515, Bibcode:2008M&PS...43..497G, doi:10.1111/j.1945-5100.2008.tb00668.x 
  6. ^ Smales, A. A.; Mapper, D.; Wood, A. J. (1958), "Radioactivation analysis of "cosmic" and other magnetic spherules", Geochimica et Cosmochimica Acta, 13 (2–3): 123–126, Bibcode:1958GeCoA..13..123S, doi:10.1016/0016-7037(58)90043-7 
  7. ^ a b Marvin, U. B.; Marvin, M. T. (1967), "Black, Magnetic Spherules from Pleistocene and Recent beach sands", Geochimica et Cosmochimica Acta, 31 (10): 1871–1884, Bibcode:1967GeCoA..31.1871E, doi:10.1016/0016-7037(67)90128-7 
  8. ^ Blanchard, M. B.; Brownlee, D. E.; Bunch, T. E.; Hodge, P. W.; Kyte, F. T. (1980), "Meteoroid ablation spheres from deep-sea sediments", Earth Planet. Sci. Lett., 46 (2): 178–190, Bibcode:1980E&PSL..46..178B, doi:10.1016/0012-821X(80)90004-7 
  9. ^ Ganapathy, R.; Brownlee, D. E.; Hodge, T. E.; Hodge, P. W. (1978), "Silicate spherules from deep-sea sediments: Confirmation of extraterrestrial origin", Science, 201 (4361): 1119–1121, Bibcode:1978Sci...201.1119G, doi:10.1126/science.201.4361.1119, PMID 17830315 
  10. ^ a b Raisbeck, G. M.; Yiou, F.; Bourles, D.; Maurette, M. (1986), "10Be and 26Al in Greenland cosmic spherules: Evidence for irradiation in space as small objects and a probable cometary origin", Meteoritics, 21: 487–488, Bibcode:1986Metic..21..487R 
  11. ^ Nishiizumi, K.; Arnold, J. R.; Brownlee, D. E.; Finkel, R. C.; Harvey, R. P.; et al. (1995), "10Be and 26Al in individual cosmic spherules from Antarctica", Meteoritics, 30 (6): 728–732, doi:10.1111/j.1945-5100.1995.tb01170.x  |first4= missing |last4= in Authors list (help)
  12. ^ Yada, T.; Floss, C.; Zinner, Ernst; Nakamura, Tomoki; Noguchi, Takaaki; Lea, A. Scott; et al. (2008), "Stardust in Antarctic micrometeorites", Meteoritical & Planetary Science, 43 (8): 1287–1298, Bibcode:2008M&PS...43.1287Y, doi:10.1111/j.1945-5100.2008.tb00698.x  |first3= missing |last3= in Authors list (help)
  13. ^ a b Duprat, J. E.; Dobrică, C.; Engrand, J.; Aléon, Y.; Marrocchi, Y.; Mostefaoui, S.; Meibom, A.; Leroux, H.; et al. (2010), "Extreme Deuterium excesses in ultracarbonaceous Micrometeorites from Central Antarctic Snow", Science, 328 (5979): 742–745, Bibcode:2010Sci...328..742D, doi:10.1126/science.1184832, PMID 20448182 
  14. ^ a b Taylor, S.; Lever, J. H.; Harvey, R. P. (1998), "Accretion rate of cosmic spherules measured at the South Pole", Nature, 392 (6679): 899–903, Bibcode:1998Natur.392..899T, doi:10.1038/31894, PMID 9582069 
  15. ^ Zolensky, M.; Bland, M.; Brown, P.; Halliday, I. (2006), "Flux of extraterrestrial materials", in Lauretta, Dante S.; McSween, Harry Y., Meteorites and the Early Solar System II, Tucson: University of Arizona Press 
  16. ^ Taylor, S.; Schmitz, J.H. (2001), Peucker-Erhenbrink, B.; Schmitz, B., eds., "Accretion of Extraterrestrial matter throughout Earth's history—Seeking unbiased collections of modern and ancient micrometeorites", Accretion of extraterrestrial matter throughout earth's history/ edited by Bernhard Peucker-Ehrenbrink and Birger Schmitz; New York: Kluwer Academic/Plenum Publishers, New York: Kluwer Academic/Plenum Publishers: 205–219, Bibcode:2001aemt.book.....P, doi:10.1007/978-1-4419-8694-8_12, ISBN 978-1-4613-4668-5 
  17. ^ Murray, J.; Renard, A. F. (1891), "Report on the scientific results of the voyage of H.M.S. Challenger during the years 1873–76", Deep-Sea Deposits: 327–336 
  18. ^ Murray, J.; Renard, A. F. (1883), "On the microscopic characters of volcanic ashes and cosmic dust, and their distribution in deep-sea deposits", Proceedings of the Royal Society, Edinburgh, 12: 474–495 
  19. ^ Brownlee, D. E.; Bates, B. A.; Wheelock, M. M. (1984-06-21), "Extraterrestrial platinum group nuggets in deep-sea sediments", Nature, 309 (5970): 693–695, Bibcode:1984Natur.309..693B, doi:10.1038/309693a0 
  20. ^ Brunn, A. F.; Langer, E.; Pauly, H. (1955), "Magnetic particles found by raking the deep-sea bottom", Deep-Sea Research, 2 (3): 230–246, Bibcode:1955DSR.....2..230B, doi:10.1016/0146-6313(55)90027-7 
  21. ^ Brownlee, D. E.; Pilachowski, L. B.; Hodge, P. W. (1979), "Meteorite mining on the ocean floor (abstract)", Lunar Planet. Sci., X: 157–158 
  22. ^ Crozier, W. D. (1960), "Black, magnetic spherules in sediments", Journal of Geophysical Research, 65 (9): 2971–2977, Bibcode:1960JGR....65.2971C, doi:10.1029/JZ065i009p02971 
  23. ^ a b Czajkowski, J.; Englert, P.; Bosellini, A.; Ogg, J. G. (1983), "Cobalt enriched hardgrounds-new sources of ancient extraterrestrial materials", Meteoritics, 18: 286–287, Bibcode:1983Metic..18..286C 
  24. ^ Jehanno, C.; Boclet, D.; Bonte, Ph.; Castellarin, A.; Rocchia, R. (1988), "Identification of two populations of extraterrestrial particles in a Jurassic hardground of the Southern Alps", Proc. Lun. Planet. Sci. Conf., 18: 623–630, Bibcode:1988LPSC...18..623J 
  25. ^ Mutch, T.A. (1966), "Abundance of magnetic spherules in Silurian and Permian salt samples", Earth and Planetary Science Letters, 1 (5): 325–329, Bibcode:1966E&PSL...1..325M, doi:10.1016/0012-821X(66)90016-1 
  26. ^ Taylor, S.; Brownlee, D. E. (1991), "Cosmic spherules in the geologic record", Meteoritics, 26 (3): 203–211, Bibcode:1991Metic..26..203T, doi:10.1111/j.1945-5100.1991.tb01040.x 
  27. ^ Fredriksson, K.; Gowdy, R. (1963), "Meteoritic debris from the Southern California desert", Geochimica et Cosmochimica Acta, 27 (3): 241–243, Bibcode:1963GeCoA..27..241F, doi:10.1016/0016-7037(63)90025-5 
  28. ^ Muhs, Eric. "Micrometeorites". Ice Cube—South Pole Neutrino Laboratory. University of Wisconsin at River Falls Physics Department. Retrieved 2015-04-19. 
  29. ^ Langway, C. C. (1963), "Sampling for extra-terrestrial dust on the Greenland Ice Sheet", Union Geodesique et Geophysique Internationale, Association Internationale d'Hydrologie Scientific, Berkeley Symposium, 61: 189–197 
  30. ^ Wulfing, E. A. (1890), "Beitrag zur Kenntniss des Kryokonit", Neus Jahrb. Für Min., etc., 7: 152–174 
  31. ^ Maurette, M.; Hammer, C.; Reeh, D. E.; Brownlee, D. E.; Thomsen, H. H. (1986), "Placers of cosmic dust in the blue ice lakes of Greenland", Science, 233 (4766): 869–872, Bibcode:1986Sci...233..869M, doi:10.1126/science.233.4766.869, PMID 17752213 
  32. ^ Maurette, M.; Jehanno, C.; Robin, E.; Hammer, C. (1987), "Characteristics and mass distribution of extraterrestrial dust from the Greenland ice cap", Nature, 328 (6132): 699–702, Bibcode:1987Natur.328..699M, doi:10.1038/328699a0 
  33. ^ Maurette, M.; Olinger, C.; Michel-Levy, M.; Kurat, G.; Pourchet, M.; Brandstatter, F.; Bourot-Denise, M. (1991), "A collection of diverse micrometeorites recovered from 100 tonnes of Antarctic blue ice", Nature, 351 (6321): 44–47, Bibcode:1991Natur.351...44M, doi:10.1038/351044a0 
  34. ^ Koeberl, C.; Hagen, E. H. (1989), "Extraterrestrial spherules in glacial sediment from the Transantarctic Mountains, Antarctica: Structure, mineralogy and chemical composition", Geochimica et Cosmochimica Acta, 53 (4): 937–944, Bibcode:1989GeCoA..53..937K, doi:10.1016/0016-7037(89)90039-2 
  35. ^ Hagen, E. H.; Koeberl, C.; Faure, G. (1990), "Extraterrestrial spherules in glacial sediment, Beardmore Glacier area, Transantarctic Mountain", Antarctic Research Series, Antarctic Research Series, 50: 19–24, doi:10.1029/AR050p0019, ISBN 0-87590-760-1 
  36. ^ Koeberl, C.; Hagen, E. H. (1989), "Extraterrestrial spherules in glacial sediment from the Transantarctic Mountains, Antarctica: Structure, mineralogy and chemical composition", Geochimica et Cosmochimica Acta, 53 (4): 937–944, Bibcode:1989GeCoA..53..937K, doi:10.1016/0016-7037(89)90039-2 
  37. ^ Yiou, F.; Raisbeck, G. M. (1987), "Cosmic spherules from an Antarctic ice core", Meteoritics, 22: 539–540, Bibcode:1987Metic..22..539Y 
  38. ^ Rochette, P.; Folco, L.; Suavet, M.; Van Ginneken, M.; Gattacceca, J; Perchiazzi, N; Braucher, R; Harvey, RP (2008), "Micrometeorites from the Transantarctic Mountains", PNAS, 105 (47): 18206–18211, Bibcode:2008PNAS..10518206R, doi:10.1073/pnas.0806049105, PMC 2583132free to read, PMID 19011091 
  39. ^ Krot, A. N.; Keil, K.; Scott, E. R. D.; Goodrich, C. A.; Weisberg, M. K. (2007), "1.05 Classification of Meteorites", in Holland, Heinrich D.; Turekian, Karl K., Treatise on Geochemistry, 1, Elsevier Ltd, pp. 83–128, doi:10.1016/B0-08-043751-6/01062-8, ISBN 978-0-08-043751-4 
  40. ^ Genge, M. J.; Engrand, C.; Gounelle, M.; Taylor, S. (2008), "The classification of micrometeorites" (PDF), Meteoritics & Planetary Science, 43 (3): 497–515, Bibcode:2008M&PS...43..497G, doi:10.1111/j.1945-5100.2008.tb00668.x, retrieved 2013-01-13 
  41. ^ Taylor, S.; Herzog, G. F.; Delaney, J. S. (2007), "Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well", Meteoritics and Planetary Sciences, 42 (2): 223–233, Bibcode:2007M&PS...42..223T, doi:10.1111/j.1945-5100.2007.tb00229.x 
  42. ^ Cordier, C.; Folco, L.; Taylor, S. (2011), "Vestoid cosmic spherules from the South Pole Water Well and Transantarctic Mountains (Antarctica): A major and trace element study", Geochimica et Cosmochimica Acta, 75 (5): 1199–1215, Bibcode:2011GeCoA..75.1199C, doi:10.1016/j.gca.2010.11.024 
  43. ^ Kurat, G.; Koeberl, C.; Presper, T.; Brandstätter, Franz; Maurette, Michel (1994), "Petrology and geochemistry of Antarctic micrometeorites", Geochimica et Cosmochimica Acta, 58 (18): 3879–3904, Bibcode:1994GeCoA..58.3879K, doi:10.1016/0016-7037(94)90369-7 
  44. ^ Beckerling, W.; Bischoff, A. (1995), "Occurrence and composition of relict minerals in micrometeorites from Greenland and Antarctica—implications for their origins", Planetary and Space Science, 43 (3–4): 435–449, Bibcode:1995P&SS...43..435B, doi:10.1016/0032-0633(94)00175-Q 
  45. ^ Greshake, A.; Kloeck, W.; Arndt, P.; Maetz, Mischa; Flynn, George J.; Bajt, Sasa; Bischoff, Addi (1998), "Heating experiments simulating atmospheric entry heating of micrometeorites: Clues to their parent body sources", Meteoritics & Planetary Science, 33 (2): 267–290, Bibcode:1998M&PS...33..267G, doi:10.1111/j.1945-5100.1998.tb01632.x 
  46. ^ Sears, D. W. G. (1998), "The Case for Rarity of Chondrules and Calcium-Aluminum-rich Inclusions in the Early Solar System and Some Implications for Astrophysical Models", Astrophysical Journal, 498 (2): 773–778, Bibcode:1998ApJ...498..773S, doi:10.1086/305589 
  47. ^ Engrand, C.; Maurette, M. (1998), "Carbonaceous micrometeorites from Antarctica", Meteoritics and Planetary Sciences, 33 (4): 565–580, Bibcode:1998M&PS...33..565E, doi:10.1111/j.1945-5100.1998.tb01665.x 
  48. ^ Nesvorny, D.; Jenniskens, P.; Levison, H. F.; Bottke, William F.; Vokrouhlický, David; Gounelle, Matthieu (2010), "Cometary origin of the zodiacal cloud and carbonaceous micrometeorites. Implications for hot debris disks", The Astrophysical Journal, 713 (2): 816–836, arXiv:0909.4322free to read, Bibcode:2010ApJ...713..816N, doi:10.1088/0004-637X/713/2/816 
  49. ^ Brownlee, D. E.; Tsou, Peter; Aléon, Jérôme; Alexander, Conel M. O.'D.; Araki, Tohru; Bajt, Sasa; Baratta, Giuseppe A.; Bastien, Ron; et al. (2006), "Comet 81P/Wild 2 Under a Microscope", Science, 314 (5806): 1711–1716, Bibcode:2006Sci...314.1711B, doi:10.1126/science.1135840, PMID 17170289 
  50. ^ Joswiak, D. J.; Brownlee, D. E.; Matrajt, G.; Westphal, Andrew J.; Snead, Christopher J.; Gainsforth, Zack (2012), "Comprehensive examination of large mineral and rock fragments in Stardust tracks: Mineralogy, analogous extraterrestrial materials, and source regions", Meteoritics & Planetary Science, 47 (4): 471–524, Bibcode:2012M&PS...47..471J, doi:10.1111/j.1945-5100.2012.01337.x 
  51. ^ Genge, M. J.; Gileski, A.; Grady, M. M. (2005), "Chondrules in Antarctic micrometeorites" (PDF), Meteoritics & Planetary Science, 40 (2): 225–238, Bibcode:2005M&PS...40..225G, doi:10.1111/j.1945-5100.2005.tb00377.x, retrieved 2013-01-13 
  52. ^ Flynn, George J.; McKay, David S. (1 January 1990), "An assessment of the meteoritic contribution to the martian soil", Journal of Geophysical Research, 95 (B9): 14497, Bibcode:1990JGR....9514497F, doi:10.1029/JB095iB09p14497 

Further reading[edit]

  • Castaing, R.; Fredriksson, K. (1958), "Analysis of Cosmic Spherules with an X-Ray Microanalyser", Geochimica et Cosmochimica Acta, 14: 114–117, Bibcode:1958GeCoA..14..114C, doi:10.1016/0016-7037(58)90099-1 
  • Dobrica, E.; Engrand, C.; Duprat, J.; Gounelle, M. (2010), "A statistical overview of Concordia Antarctic micrometeorites", 73rd Meteoritical Society, 73: pdf 5213, Bibcode:2010M&PSA..73.5213D 
  • Duprat, J. E.; Engrand, C.; Maurette, M.; Gounelle, M.; Hammer, C.; et al. (2007), "Micrometeorites from Central Antarctic snow: The CONCORDIA collection", Advances in Space Research, 39 (4): 605–611, Bibcode:2007AdSpR..39..605D, doi:10.1016/j.asr.2006.05.029  |first4= missing |last4= in Authors list (help)
  • Engrand, C.; McKeegan, K. D.; Leshin, L. A. (1999), "Oxygen isotopic composition of individual minerals in Antarctic micrometeorites: Further links to carbonaceous chondrites", Geochimica et Cosmochimica Acta, 63 (17): 2623–2636, Bibcode:1999GeCoA..63.2623E, doi:10.1016/S0016-7037(99)00160-X 
  • Flynn, G. J. (1989), "Atmospheric entry heating: a criterion to distinguish between asteroidal and cometary sources of interplanetary dust", Icarus, 77 (2): 287–310, Bibcode:1989Icar...77..287F, doi:10.1016/0019-1035(89)90091-2 
  • Genge, M. J.; Grady, M. M.; Hutchison, R. (1997), "The textures and compositions of fine-grained Antarctic micrometeorites: Implications for comparisons with meteorites", Geochimica et Cosmochimica Acta, 61 (23): 5149–5162, Bibcode:1997GeCoA..61.5149G, doi:10.1016/S0016-7037(97)00308-6 
  • Goodrich, C. A.; Delaney, J. S. (2000), "Fe/Mg-Fe/Mn relations of meteorites and primary heterogeneity of primitive achondrite parent bodies", Geochimica et Cosmochimicha Acta, 64: 149–160., Bibcode:2000GeCoA..64..149G, doi:10.1016/S0016-7037(99)00107-6 
  • Gounelle, M.; Chaussidon, M.; Morbidelli, A.; Engrand, C; Zolensky, ME; McKeegan, KD; et al. (2009), "A unique basaltic micrometeorite expands the inventory of solar system planetary crusts", Proc. Natl. Acad. Sci. U.S.A., 106 (17): 6904–6909, Bibcode:2009PNAS..106.6904G, doi:10.1073/pnas.0900328106, PMC 2678474free to read, PMID 19366660  |first4= missing |last4= in Authors list (help)
  • Grun, E.; Zook, H. A.; Fechtig, H.; Geise, R. H. (1985), "Collisional balance of the meteoritic complex", Icarus, 62 (2): 244–272, Bibcode:1985Icar...62..244G, doi:10.1016/0019-1035(85)90121-6 
  • Harvey, R. P.; Maurette, M. (1991), "The origin and significance of cosmic dust from the Walcott Neve, Antarctica", Proceedings of Lunar and Planetary Science, 21: 569–578 
  • Hashimoto, A. (1983), "Evaporation metamorphism in the early solar nebula—evaporation experiments on the melt FeO-MgO-SiO2-CaO-Al2O3 and chemical fractionations of primitive materials", Geochemical Journal, 17 (3): 111–145, doi:10.2343/geochemj.17.111 
  • Herzog, G. F.; Xue, S.; Hall, G. S.; Nyquist, L. E.; Shih, C. -Y.; Wiesmann, H.; Brownlee, D. E. (1999), "Isotopic and elemental composition of iron, nickel, and chromium in type I deep-sea spherules: implications for origin and composition of the parent micrometeoroids", Geochimica et Cosmochimica Acta, 63 (9): 1443–1457, Bibcode:1999GeCoA..63.1443H, doi:10.1016/S0016-7037(99)00011-3 
  • Imae, N.; Taylor, S.; Iwata, N. (2013), "Coarse-grained relict minerals in Antarctic micrometeorites: Links to chondrites and comets", Geochimica et Cosmochimica Acta, 100: 116–157 
  • Kyte, F. T. (1983), "Analyses of extraterrestrial materials in terrestrial sediments", PhD thesis, Los Angeles: University of California: 152 pp 
  • Love, S. G.; Brownlee, D. E. (1991), "Heating and thermal transformation of micrometeoroids entering the earth's atmosphere", Icarus, 89: 26–43, Bibcode:1991Icar...89...26L, doi:10.1016/0019-1035(91)90085-8 
  • Matrajt, G.; Pizzarello, S.; Taylor, S.; Brownlee, D. (2004), "Concentration and variability of the AIB amino acid in polar micrometeorites: Implications for the exogenous delivery of amino acids to the primitive Earth", Meteoritics and Planetary Science, 39 (11): 1849–1858, Bibcode:2004M&PS...39.1849M, doi:10.1111/j.1945-5100.2004.tb00080.x 
  • Matrajt, G. S.; Taylor, S.; Flynn, G.; Joswiak, D.; et al. (2003), "A nuclear microprobe study of the distribution and concentration of carbon and nitrogen in Murchison and Tagish Lake meteorites, Antarctic micrometeorites, and IDPS: Implications for astrobiology", Meteoritics and Planetary Science, 38 (11): 1585–1600, Bibcode:2003M&PS...38.1585M, doi:10.1111/j.1945-5100.2003.tb00003.x  |first4= missing |last4= in Authors list (help)
  • Millard, H. T.; Finkelman, R. B. (1970), "Chemical and mineralogical compositions of cosmic and terrestrial spherules from a marine sediment", Journal of Geophysical Research, 75 (11): 2125–2133, Bibcode:1970JGR....75.2125M, doi:10.1029/JB075i011p02125 
  • Murrell, M. T.; Davis, P. A.; Nishiizumi, K.; Millard, H. T. (1980), "Deep-sea spherules from Pacific clay: mass distribution and influx rate", Geochimica et Cosmochimica Acta, 44 (12): 2067–2074, Bibcode:1980GeCoA..44.2067M, doi:10.1016/0016-7037(80)90204-5 
  • Nishiizumi, K. (1983), "Measurement of 53Mn in deep-sea iron and stony spherules", Earth and Planetary Science Letters, 63 (2): 223–228, Bibcode:1983E&PSL..63..223N, doi:10.1016/0012-821X(83)90038-9 
  • Pettersson, H.; Fredriksson, K. (1958), "Magnetic Spherules in Deep-sea Deposits", Pacific Science, 12: 71–81 
  • Taylor, S.; Matrajt, G.; Guan, Y. (2012), "Fine-grained precursors dominate the micrometeorite flux", Meteoritics and Planetary Sciences, 47 (4): 550–564, Bibcode:2012M&PS...47..550T, doi:10.1111/j.1945-5100.2011.01292.x 
  • Van Ginneken, M.; Folco, L.; Cordier, C.; Rochette, P. (2012), "Chondritic micrometeorites from the Transantarctic Mountains", Meteoritics and Planetary Sciences, 47 (2): 228–247, Bibcode:2012M&PS...47..228V, doi:10.1111/j.1945-5100.2011.01322.x 

External links[edit]