I'r - Memorial University of Newfoundland

unaffected by the contaminated flow and results in lowest PAM concentration within the
Western Basin (Fig. 4.1.1, 4.1.4a). The absence ofsediment laden flow at this site is also
confinned by the low sedimentation rates observed here (Fig. 5.1.6). However, total PAM
concentration at this station is somewhat higher that at the majority ofsites within the
cluster (Fig. 4.I.4a), while the isotopic composition ofPAH assemblage resembles that at
Detroit (Fig. 4.2.la). This peripberallnfluence ofthe Detroit River flow seems to make
this station transitional between clusters 2 and 3.
The incorporation ofstation 966 into this cluster (Fig. 5.1.1) can be attributed to
somewhat different reasons. The flow ofthe Detroit River in this part ofthe Western
Basin is deflected towards the shore and thus would incvi&bly hit the station. This is
indicated by high ly elevated PAH concentrations as compared to other stations in the
cl uster (Fig. 4.1.1. 4.I.4a). However. the isotopi c composition oftbis station
demonstrates the lightest values in the range (Fig. 4.1.5, 4.1 .83, 5.1.4). This characteristic
signature implies presence ofa local source ofPAH pollution depleted in ,sIlC .
In the Eastern Basin. the incorporation ofstation 932 (Fig. 5.LI) can again be
attributed to the specific circulation pattern observed here . The flow ofthe only close
fluvi al system, the Grand River , docs not seem to significantly affect this station. This is
indicated by the directions ofdrift objects studied by Canada Center for lnJand Waters
(Hamblin, 197 1; Fig. S.U 3). The figures show instead that station 932 is affectedby the
flow originating in the central part ofthe Central Basin while the outflow ofthe Grand
River seems to proceed along the northern shore towards the Niagara River outlet. Since
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