I'r - Memorial University of Newfoundland

These sources contribute as much as 100%. to the formation of BePIBaP at stations 951,
t021 , and 946. At the same stations, 60%, 70"4. and 100% respectively ofFa seem to
have derived from petroleum. At station 953 the greatest influenceofpetroleum is
demonstrated by Py( IOOO/o). and BePIBaP (80"10). Isotopic composition ofonly two
compounds were utilized for mass balance calculations at Wheatley. However, both of
them indicate presenceofpetroleum derived PAR (Py= 50%, Fa=15% ).
In addition. some pcttoleum influence can be detected in the Eastern Basin. Stations
23 and 935 demonstrate 45· 50"/0 and 30-60% ofBePlBaP and Cby produced from
petro leum-re lated sources . At station 932, as much as 60% ofChy is formed from
petro leum. Unfortunately. its relative contribution to the formation o f higher molecular
weight compo unds cannot be estimated at this station due to missing values.
To conclude . the compari son of sample isotopic values to characteristic signatures of
the primary sources and mass balanc e calculations showed that although combustion
sources are predominant throughout the lake, two major zones ofhigh relative importance
of petro leum are observed . The first zone is located in the Western Basin. Here , stations
97 1.969. and 966 seem to be affected the most. The second region is found in the
northern part of the Centra l Basin . The sites within thiszone demonstrate even greater
relative contribution of petroleum. Finally, there is an indication ofpetroleum input in
the Eastern Basin .
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