The factor that had the most control over the paleoenvironment of the Champlain Sea was salinity.  Using current knowledge of the distribution of modern foraminiferal species, the paleosalinity was essentially reconstructed.  Two important things were determined; that the salinity of the bottom water decreased with time, and that the marine environment was divided into three salinity zones.  The first and upper zone was characterized by high salinity (30-34 ) as it contained the foraminiferal assemblages defined by Cassidulina reniforme (shown at left), Islandiella helenae, Islandiella norcossi and Astrononion gallowayi.  These species are known to live within the aforementioned salinity range.  The next zone, the intermediate salinity zone, is 
characterized by the foraminifera assemblages defined by the species Elphidium clavatum and Haynesia orbiculari.  The salinity here ranged from 15 - 30 .  The final zone was of low salinity bottom waters (<15 ) and was characterized by Elphidium sp.

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