TY - JOUR
T1 - The discovery of Lake Hephaestus, the youngest athalassohaline deep-sea formation on Earth
AU - La Cono, Violetta
AU - Bortoluzzi, Giovanni
AU - Messina, Enzo
AU - La Spada, Gina
AU - Smedile, Francesco
AU - Giuliano, Laura
AU - Borghini, Mireno
AU - Stumpp, Christine
AU - Schmitt-Kopplin, Philippe
AU - Harir, Mourad
AU - O’Neill, William K.
AU - Hallsworth, John E.
AU - Yakimov, Michail
N1 - Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Hydrated, magnesium-rich minerals and subglacial brines exist on the martian surface, so the habitability of high-Mg2+ environments on Earth has extraterrestrial (as well as terrestrial) implications. Here, we report the discovery of a MgCl2-dominated (4.72 M) brine lake on the floor of the Mediterranean Ridge that underlies a 3500-m water column, and name it Lake Hephaestus. Stable isotope analyses indicated that the Hephaestus brine is derived from interactions between ancient bishofite-enriched evaporites and subsurface fluids. Analyses of sediment pore waters indicated that the Hephaestus depression had contained the MgCl2 brine for a remarkably short period; only 700 years. Lake Hephaestus is, therefore, the youngest among currently known submarine athalassohaline brine lakes on Earth. Due to its biologically hostile properties (low water-activity and extreme chaotropicity), the Hephaestus brine is devoid of life. By contrast, the seawater-Hephaestus brine interface has been shown to act as refuge for extremely halophilic and magnesium-adapted stratified communities of microbes, even at MgCl2 concentrations that approach the water-activity limit for life (0.653).
AB - Hydrated, magnesium-rich minerals and subglacial brines exist on the martian surface, so the habitability of high-Mg2+ environments on Earth has extraterrestrial (as well as terrestrial) implications. Here, we report the discovery of a MgCl2-dominated (4.72 M) brine lake on the floor of the Mediterranean Ridge that underlies a 3500-m water column, and name it Lake Hephaestus. Stable isotope analyses indicated that the Hephaestus brine is derived from interactions between ancient bishofite-enriched evaporites and subsurface fluids. Analyses of sediment pore waters indicated that the Hephaestus depression had contained the MgCl2 brine for a remarkably short period; only 700 years. Lake Hephaestus is, therefore, the youngest among currently known submarine athalassohaline brine lakes on Earth. Due to its biologically hostile properties (low water-activity and extreme chaotropicity), the Hephaestus brine is devoid of life. By contrast, the seawater-Hephaestus brine interface has been shown to act as refuge for extremely halophilic and magnesium-adapted stratified communities of microbes, even at MgCl2 concentrations that approach the water-activity limit for life (0.653).
UR - http://www.scopus.com/inward/record.url?scp=85061230913&partnerID=8YFLogxK
U2 - 10.1038/s41598-018-38444-z
DO - 10.1038/s41598-018-38444-z
M3 - Article
C2 - 30737448
AN - SCOPUS:85061230913
VL - 9
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 1679
ER -