Chemical studies of L chondrites. IV. Antarctic/non-Antarctic comparisons

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(89)90400-6· OSTI ID:5097904

Kaczaral, P W ^[1]; Dodd, R T ^[2]; Lipschutz, M E ^[3]

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1. DuPont Corp., Deepwater, NJ (USA)
2. SUNY, Stony Brook, NY (USA)
3. Purdue Univ., West Lafayette, IN (USA)

The authors report shock facies and RNAA data for 13 siderophile, lithophile and chalcophile volatile/mobile trace elements (Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Se, Te, Tl, Zn) in interior portions of 19 different L3-6 chondrites from Victoria Land, Antarctica. Comparison of these data for essentially unweathered Antarctic samples with those previously published for 39 L4-6 chondrite falls indicate substantial differences. The Victoria Land population lacks the most heavily shocked (>35 GPa) representatives found in the non-Antarctic population. While contents of nearly all trace elements studied are lower at statistically significant levels in strongly shocked (>22 GPa) falls than in mildly shocked (<22 GPa) ones, this is not true for the Victoria Land population. Contents of most trace elements vary with petrologic type of heavily shocked (facies d, 22-35 GPa) L chondrites from Victoria Land: such a variation is not observed for non-Antarctic falls or mildly shocked samples of either population. L4-6 chondrites from Victoria Land contain significantly lesser amounts of nearly every trace element than do falls. While Antarctic weathering could account for the compositional differences between Antarctic and non-Antarctic L chondrites, such processes cannot be responsible for the shock differences observed. Physical and chemical differences between other sorts of Antarctic and non-Antarctic meteorites suggest, rather, that the L chondrite differences are preterrestrial in origin. If so, the parent region(s) for the Victoria Land samples--that fell to earth 0.1 to 1 Myr ago--generally formed and/or evolved under higher temperature conditions than those regions yielding contemporary falls. The dominant influence of late shock that altered mobile trace element contents of L chondrite falls is not evident in samples from Victoria Land.

• OSTI ID: 5097904
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 53:2; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ABUNDANCE
ALKALI METALS
ANTARCTIC REGIONS
ANTARCTICA
BISMUTH
CADMIUM
CESIUM
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
CHONDRITES
COBALT
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
ELEMENT ABUNDANCE
ELEMENTS
GALLIUM
GEOCHEMISTRY
GEOLOGIC HISTORY
GOLD
IMPACT SHOCK
INDIUM
METALS
METEORITES
ORIGIN
POLAR REGIONS
QUANTITATIVE CHEMICAL ANALYSIS
RUBIDIUM
SELENIUM
SEMIMETALS
SILVER
STONE METEORITES
TELLURIUM
THALLIUM
TRANSITION ELEMENTS
ZINC