Geochemical investigations to explain iodine-overabundances in Antarctic meteorites
Iodine, bromine, and chlorine concentrations were determined in different Antarctic meteorite specimens with isotope dilution mass spectrometry. In all Antarctic meteorites I-overabundances have been analyzed compared with the concentrations for non-Antarctic meteorites of the same class. Half of the Antarctic specimens show especially high concentrations of more than 1 ..mu..g/g. By analyzing different types of Antarctic rocks, a significant decrease of the I concentration-but not of the Br and Cl concentration-was determined from the surfaces to the centers of the rocks. This shows that atmospheric I compounds interact with the surfaces of Antarctic rocks and, therefore, with those of Antarctic meteorites as well. Analyses of atmospheric halogens show that the gaseous compound CH/sub 3/I is probably responsible for the I-overabundance in Antarctic meteorites and rocks. Chloride and bromide are found in particles derived from sea-spray in Antarctic aerosols. Deposition of halogens in Antarctic snow near the coast shows I/Cl ratios 10-190 higher than the average value for sea water. The corresponding Br/Cl ratios are in the same range as sea water. On the basis of these results and of other reported data the authors construct a preliminary hypothesis for a geochemical I cycle in Antarctica, taking into consideration long-distance and short-distance transportation of different I compounds from the coast to inland Antarctica.
- Research Organization:
- Universitaetsstrasse, Regensburg (West Germany)
- OSTI ID:
- 5100007
- Journal Information:
- Geochim. Cosmochim. Acta; (United States), Journal Name: Geochim. Cosmochim. Acta; (United States) Vol. 51:9; ISSN GCACA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
580400* -- Geochemistry-- (-1989)
ANTARCTIC REGIONS
ANTARCTICA
BROMINE
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMISTRY
CHLORINE
CHONDRITES
ELEMENTS
GEOCHEMISTRY
GEOLOGIC HISTORY
GEOLOGIC MODELS
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
IODINE
ISOTOPE RATIO
KINETICS
MASS SPECTROSCOPY
METEORITES
NONMETALS
OXYGEN COMPOUNDS
POLAR REGIONS
QUANTITY RATIO
REACTION KINETICS
SEAWATER
SPECTROSCOPY
STONE METEORITES
WATER