He, Ne and Ar in chondritic Ni---Fe as irradiation hardness sensors

Details He, Ne and Ar in chondritic Ni---Fe as irradiation hardness sensors He, Ne and Ar in chondritic Ni---Fe as irradiation hardness sensors

Jul 1973

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1973gecoa..37.1655n&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 37, Issue 7, pp.1655-1685

Physics

6

Scientific paper

Noble gas analyses of the Ni-Fe of 9 L, 5 H and 2 LL chondrites quantitatively support previous suggestions of radiogenic 4 He recoil and 3 He deficits. Furthermore, noble gases in the Ni-Fe show evidence for in situ produced radiogenic 4 He and in some cases for recoil loss of 38 Ar and gain of 21 Ne. The ratio of spallogenic 21 Ne and 38 Ar in the metal phase is found to correlate strongly with 3 He/ 21 Ne and 22 Ne/ 21 Ne in bulk samples of these chondrites. This is proof of the dependence of these ratios on the irradiation hardness experienced by the meteoroid in space. `Hardness indices' n = 1.9-2.2 are found, indicating that on the average the stone meteoroids from which the samples came were smaller in mass than iron meteoroids. The spallogenic 21 Ne/ 38 Ar ratio in metallic Ni-Fe can be used with the semi-empirical production model deduced from the Grant iron meteorite to calibrate spallogenic 3 He/ 21 Ne and 4 Ne/ 21 Ne in bulk samples of L, LL and H chondrites for meteoroid size and sample location allowing the estimation of minimal meteoroid masses. 3 He and 21 Ne production rates calculated from previously determined 36 Ar/ 38 Ar exposure ages for four L chondrites indicate that they are probably not single-valued functions of the 3 He/ 21 Ne ratio. The ratio of 3 He in bulk samples to 38 Ar in metal samples of the same meteorite is constant ( = 20 ± 3) whereas the ratio of 21 Ne in the bulk to 38 Ar in the metal varies by as much as a factor of two in correlation with 3 He/ 21 Ne.

Affiliated with

Also associated with

No associations

Rating

He, Ne and Ar in chondritic Ni---Fe as irradiation hardness sensors does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with He, Ne and Ar in chondritic Ni---Fe as irradiation hardness sensors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and He, Ne and Ar in chondritic Ni---Fe as irradiation hardness sensors will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1688939