LOW BE-10 AND AL-26 CONTENTS OF UREILITES - PRODUCTION AT METEOROID SURFACES

被引：13

作者：

AYLMER, D ^{[1
]}

VOGT, S ^{[1
]}

HERZOG, GF ^{[1
]}

KLEIN, J ^{[1
]}

FINK, D ^{[1
]}

MIDDLETON, R ^{[1
]}

机构：

[1] UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104

来源：

GEOCHIMICA ET COSMOCHIMICA ACTA | 1990年 / 54卷 / 06期

关键词：

D O I：

10.1016/0016-7037(90)90407-C

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

We report the 10Be contents of 22 ureilites and the 26Al contents of 18 ureilites. When corrected for exposure age, where known, and for composition, the results give production rates, P, that are on average 20% lower than values typical of other meteorite classes. This depression of production rates, the weak correlation of both 26 and P10 with 22Ne 21Ne, and the generally high 3He 21Ne and 22Ne 21Ne ratios in ureilites all suggest that many of the samples occupied near-surface locations in their parent meteoroids. A reduced flux of cosmic rays does not by itself explain the elevated 22Ne 21Ne ratios and appears inconsistent with a proposed source for ureilites in the inner asteroid belt. Cosmogenic radionuclide data do not support the tentative pairing of ALHA 78019 with ALHA 78262 proposed on the basis of mineralogical similarities. The high 26Al content of LEW 85440 may be the result of irradiation by solar cosmic rays. © 1990.

引用

页码：1775 / 1784

页数：10

共 57 条

[1] BE-10 AND AL-26 CONTENTS OF EUCRITES - IMPLICATIONS FOR PRODUCTION-RATES AND EXPOSURE AGES [J].