ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00456.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00457.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Knudsen cell‐quadrupole mass spectrometry has been used to quantitatively determine the composition of the vapor phase produced by heating samples of the Holbrook chondrite to 1300 °C. Maximum observed vapor pressures (atm) of metals are 10−5.3 ± 0.3Na, 10−5.8 ± 0.3K, 10−5.3 ± 0.3Fe, and 10−6.6 ± 0.3Ni at 1200 °C. S2(with minor SO2), H2O, and CO2were also observed in the high‐temperature gas phase. Release of intrinsically derived volatiles produced abundant vesicles in the heated sample residues. Some possible implications for chondrite evolution are

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00458.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00459.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The Kakangari chondrite has a cosmic‐ray exposure age of 5.4 m.y. and a K‐Ar age near 4 g.y. Its high cosmogenic3He/21Ne ratio of 7.5 indicates a small preatmospheric mass. The He and Ne are largely of solar‐wind origin, presumably implanted during exposure in the regolith of its parent body. The heavy gases Ar, Kr, Xe are largely of planetary origin. Taken together, the low129Xe/132Xe (1.07), low36Ar/132Xe (225), and high132Xe content (45 × 10−10cc STP/g) are more similar to the values for unequilibrated ordinary chondrites or even C1, C2 chondrites than to enstatite chondrites, and suggest that Kakangari has the same gas‐bearing mineral assemblage as the former, in spite of its high degree of reducti

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00460.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Four new irons are described; Buenaventura (IIIB) from Chihuahua, Mexico: mass 114 kg; Denver City (anomalous) from Texas, USA: mass 26.1 kg; Kinsella (IIIB) from Alberta, Canada: mass 3.7 kg; and Tacoma (IA) from Washington, USA: mass 17 g. Denver City is unique, i.e., not related to any other known iron. Tacoma is the smallest iron meteorite recorded. All were purchased for the UCLA collection following a publicity drive for new meteorites

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00461.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

We have measured the habit planes of plate rhabdites [(Fe, Ni)3P] with respect to the parent kamacite phase (α, Fe‐Ni) in eight hexahedrites. This was accomplished using x‐ray diffraction plus two‐surface trace analysis. Results show that plate rhabdites form on either {001} or {122} planes in the parent kamacite. The meteorite Uwet exhibits a {112} habit plane which is possibly an anomaly due to the occurrence of a large shock event during rhabdite nucleation (∼ 550

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00462.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The composition and mineralogy of Bench Crater and a new carbonaceous chondrite (Adelaide) are compared. They, Kakangari and possibly certain carbonaceous xenoliths from other meteorites constitute a distinct chemical subgroup of the carbonaceous chondrites characterized primarily by a calcium‐to‐aluminium ratio (atomic) of about 0.5. It is proposed to call this group the Kakangari (CK) g

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00463.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The results of thermal model calculations which assume26Al as a heat source are presented. The relation between26Al content, the maximum central temperature obtained, and the time interval after formation until central cooling commences is elucidated. Because of the heating times required, these results constrain maximum permissible planetoid dimensions more severely than do previous calculations which assume a high initial temperature.

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00464.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0026-1114    

DOI:10.1111/j.1945-5100.1977.tb00465.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY