Cryogenic origin for brine in the subsurface of southern McMurdo Sound, Antarctica

• Published in: Geology
• Main Authors: Frank, T. D., Gui, Z., ANDRILL SMS Science Team, Antarctica
• Other Authors: Frank, T. D.; Department of Geosciences, 214 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0340, USA, Gui, Z.; Department of Geosciences, 214 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0340, USA, ANDRILL SMS Science Team, Antarctica; Antarctic Drilling Project, Southern McMurdo Sound Project, ANDRILL Science Management Offi ce, 126 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0341, USA, ANDRILL SMS Science Team, Antarctica; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Department of Geosciences, 214 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0340, USA, Antarctic Drilling Project, Southern McMurdo Sound Project, ANDRILL Science Management Offi ce, 126 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0341, USA, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Society of America 2010
• Subjects: ANDRILL; SMS Project; interstitial fluids; hypersaline brine; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating; processes; transport; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy; McMurdo Sound; Ross Sea; Antarc*; Antarctica; Ice Sheet; Sea ice
• Online Access: http://hdl.handle.net/2122/6402; https://doi.org/10.1130/G30849.1

Sampling of interstitial fluids during deep coring in southern McMurdo Sound, Antarctica, revealed the presence of seawater-sourced, hypersaline brine at depths >200 m below the sea-floor. Na-Cl-Br and SO4-Cl-Br relationships are consistent with a concentration mechanism that involves the removal of pure H2O as ice and precipitation of mirabilite (Na2SO4·10H2O) during progressive freezing of seawater. The brine is in Neogene subglacial, glacimarine, and marine facies that record advance and retreat of glaciers through the Ross Sea embayment. In this environment, sea ice formation in semi-isolated marine basins that occupied flexural troughs along ice sheet margins produced dense brines that sank and infiltrated the permeable subglacial sediment. Repeated cycles of glacial advance and retreat provided multiple opportunities for batches of seawater to be transformed into brine that now is in the subsurface of southern McMurdo Sound. Results demonstrate the feasibility of brine formation via seawater freezing and attest to the potential of a cryogenic origin for subsurface brines in high-latitude regions of the Northern Hemisphere, as proposed by some workers. Published 587-590 2.2. Laboratorio di paleomagnetismo 3.8. Geofisica per l'ambiente JCR Journal restricted