Iron Meteorites with Low Cosmic Ray Exposure Ages

Science ◽  
1966 ◽  
Vol 151 (3717) ◽  
pp. 1524-1524 ◽  
Author(s):  
J. C. Cobb
Keyword(s):  
Cosmic Ray ◽  
Iron Meteorites ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

scholarly journals 3. Fragmentation of Asteroids and Delivery of Fragments to Earth

1977 ◽  
Vol 39 ◽  
pp. 283-291 ◽  
Author(s):  
G. W. Wetherill
Keyword(s):  
Cosmic Ray ◽  
Asteroid Belt ◽  
Combined Effects ◽  
Iron Meteorites ◽  
Exposure Age ◽  
Impact Rate ◽  
Dynamical Time ◽  
Spectrophotometric Data ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Earth-impacting meteoroids are derived from both comets and asteroids, and some uncertainty still exists regarding with which of these bodies some stone meteorites should be identified. In contrast, the long cosmic ray exposure ages of iron meteorites strongly suggest a long-lived asteroidal source capable of providing ~108 g/yr of this material to the earth’s surface over at least much of solar system history. Spectrophotometric data show that differentiated asteroids are concentrated in the inner portion of the asteroid belt. The orbital histories of fragments of inner belt asteroids are investigated, considering the combined effects of close planetary encounters, secular perturbations, and secular resonances. Particular attention is given to the low inclination (<15°) objects with small semimajcr axis (2.1 to 2.6 A.U.), which can make fairly close approaches to Mars (<0.1 A.U.). It is found that the annual yield and dynamical lifetime of collision fragments of these asteroids is in agreement with the observed impact rate and exposure age of iron meteorites. A smaller yield of stone meteorites (-107 g/yr) is expected, because elimination of these objects by collision is probable on the long dynamical time scaTe. Achondrites could be produced in this way; the yield is probably too low to account for chondrites. Chondrites could possibly be derived indirectly from these bodies insofar as these asteroids are also sources of Apollo and Amor objects.

Strahlungsalter einiger Eisenmeteorite

1964 ◽  
Vol 19 (3) ◽  
pp. 341-346 ◽  
Author(s):  
H. Voshage ◽  
D. C. Hess
Keyword(s):  
Cosmic Ray ◽  
Washington County ◽  
Iron Meteorites ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Continuing investigations described earlier the cosmic-ray exposure ages of eight iron meteorites have been determined using the 40K/41K-method. The results are: Canyon Diablo 655 + 65 Myrs, Dayton 215 ± 85 Myrs, Grant 695 ±55 Myrs, Morradal 155 ± 95 Myrs, Norfolk 680 ± 55 Myrs, Norfork 605 ± 75 Myrs, Piñon 695 ± 125 Myrs, Washington County 610 ± 70 Myrs.

Cosmic ray exposure ages of iron meteorites by the Ne21/Al26method

1965 ◽  
Vol 70 (6) ◽  
pp. 1473-1489 ◽  
Author(s):  
Michael E. Lipschutz ◽  
Peter Signer ◽  
Edward Anders
Keyword(s):  
Cosmic Ray ◽  
Iron Meteorites ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Cosmic ray exposure ages of tektites by the fission-track technique

1965 ◽  
Vol 70 (6) ◽  
pp. 1491-1496 ◽  
Author(s):  
R. L. Fleischer ◽  
C. W. Naeser ◽  
P. B. Price ◽  
R. M. Walker ◽  
M. Maurette
Keyword(s):  
Fission Track ◽  
Cosmic Ray ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

40Ar-39Ar and cosmic-ray exposure ages of nakhlites-Nakhla, Lafayette, Governador Valadares-and Chassigny

2011 ◽  
Vol 46 (9) ◽  
pp. 1397-1417 ◽  
Author(s):  
Ekaterina V. KOROCHANTSEVA ◽  
Susanne P. SCHWENZER ◽  
Alexei I. BUIKIN ◽  
Jens HOPP ◽  
Ulrich OTT ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Meteorites with short cosmic-ray exposure ages, as determined from their Al26 content

1967 ◽  
Vol 31 (10) ◽  
pp. 1793-1809 ◽  
Author(s):  
Dieter Heymann ◽  
Edward Anders ◽  
M.W Rowe
Keyword(s):  
Cosmic Ray ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

scholarly journals Cosmic Ray Exposure Age Determinations of Cosmic Spherules from Marine Sediments

1985 ◽  
Vol 85 ◽  
pp. 179-181
Author(s):  
Kazuo Yamakoshi
Keyword(s):  
Mass Spectrometry ◽  
Cosmic Ray ◽  
High Energy ◽  
High Energy Accelerator ◽  
Exposure Age ◽  
Cosmic Spherules ◽  
Inner Region ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Age ◽  
Cosmic Ray Exposure Ages

AbstractThe cosmic ray exposure ages of deep sea metalic lie spherules were determined by various methods; low level countings (Ni-59), neutron activation analysis (Mn-53), high energy accelerator mass spectrometry (Be-10, Al-26) and mass spectrometry (K isotopes). The exposure ages of 0.3 - 50 Ma were obtained. According to Poynting-Robertson effect, the starting points (supplying sources) are located at inner region of the orbit of Saturn.

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