Salty tales of diagenesis in Antarctica

Tracy Frank - University of Connecticut

Brine, with salinities reaching six times that of seawater, occurs as groundwater throughout the subsurface of the McMurdo Dry Valleys and the Victoria Land Basin, Antarctica. This brine, derived from seawater freezing, is responsible for widespread precipitation of calcite, dolomite and aragonite cement and alteration of skeletal grains in Cenozoic glaciomarine strata. Relationships among depth, sediment age, and cement precipitation temperature suggest that cement—and brine—likely formed during discrete periods of cooling and ice sheet expansion.