196Hg/202Hg ratio and Hg content in meteorites and terrestrial standard rocks: A RNAA study

P. Kumar, Mitsuru Ebihara, S. K. Bhattacharya

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Radiochemical neutron activation was applied for the determination of mercury isotopic ratios (196Hg/202Hg) for standard rock samples and meteorite samples. After neutron activation, Hg was released upon heating from 100°C to 500°C at 100°C steps and the activity ratio of 197Hg/203Hg was measured for each released fraction. After the correction for the interfering γ-rays of 75Se to 203Hg, the ratios obtained from the Dhajala meteorite (bulk and magnetically separated samples) were identical to those of the Hg monitor as well as standard rock samples (JB-1, basalt, and JG-1, granodiorite). An apparently low ratio of 196Hg/202Hg was observed at high temperature (500°C) for the Allende meteorite reference sample. As such a low value was not reproduced in another run, the presence of isotopically anomalous Hg in the Allende reference sample can not be concluded. Hg/Se ratio was observed to be very high in the non- magnetic fraction of Dhajala compared with that in the magnetic fraction, suggesting that Hg is less chalcophile than Se. Yamato 82050 (CO3) has an anomalously high content of Hg with a normal 196Hg/202Hg ratio, being at least an order of magnitude higher than the expected value. This meteorite must have been contaminated with Hg, presumably on Antarctica.

Original languageEnglish
Pages (from-to)101-116
Number of pages16
JournalGeochemical Journal
Volume35
Issue number2
DOIs
Publication statusPublished - 2001 Jan 1
Externally publishedYes

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Meteorites
meteorites
meteorite
reference sample
Rocks
rocks
Allende meteorite
rock
Neutrons
Chemical activation
isotopic ratio
granodiorite
basalt
Mercury
activation
heating
neutrons
Antarctic regions
Heating
monitors

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

Cite this

196Hg/202Hg ratio and Hg content in meteorites and terrestrial standard rocks : A RNAA study. / Kumar, P.; Ebihara, Mitsuru; Bhattacharya, S. K.

In: Geochemical Journal, Vol. 35, No. 2, 01.01.2001, p. 101-116.

Research output: Contribution to journalArticle

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