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Brine micro‐droplets and solid inclusions in accreted ice from Lake Vostok (East Antarctica)
Author(s) -
de Angelis Martine,
MorelFourcade MarieChristine,
Barnola JeanMarc,
Susini Jean,
Duval Paul
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl022460
Subject(s) - geology , glacier , brine , debris , glacial period , cryosphere , geochemistry , sea ice , geomorphology , oceanography , mineralogy , earth science , chemistry , organic chemistry
Lake Vostok, the largest Antarctic sub‐glacial lake (14,000 km 2 ), lies beneath nearly 4 km of ice. Sub‐glacial geophysical observations and studies of ice accreting at the lake‐glacier interface are the only means available to obtain information on the environment and dynamics of this huge water body formed several million years ago. Accretion ice has been studied using high‐resolution synchrotron X‐Ray micro‐fluorescence. For the first time, liquid brine micro‐droplets (3–10 μm) are observed, coexisting with large irregular sulfur‐rich aggregates (10–800 μm) containing gases and a mixture of very fine particles. Most of these objects are sequestered inside large crystals that grew slowly after ice formation. Their structure and composition support the existence of hydrothermal activity at the lake bottom and the occurrence of haline water pulses carrying fine solid debris and eventually biota from a deeper evaporitic reservoir into the lake.