In both profiles, two clearly defined diatom assemblages
delineate the marine-freshwater boundary, which occurs between
90 and 100 cm depths. 
In both profiles, two clearly defined diatom assemblages
delineate the marine-freshwater boundary, which occurs between
90 and 100 cm depths.
The bottom portion of the core is typified by an assemblage dominated by marine taxa, such as Chaetoceros species, Nitzschia cylindrus and Diploneis spp.. Above the 90 cm depths, this assemblage is replaced by a Cyclotella kuetzingiana var. planetophora dominated freshwater flora. Other freshwater species include Stephanocostis chantaicus.
Because varve counts have not been completed for this long
core and C-14 dates are inconsistent, we use sediment depths to refer to stratigraphic changes.