THE GEORGES BANK MONITORING PROGRAM: 
ANALYSIS OF TRACE METALS 
IN BOTTOM SEDIMENTS DURING THE THIRD YEAR 
OF MONITORING 
M. H. Bothner, R. R. Rendigs, E. Y. Campbell, 
M. W. Doughten, C. M. Parmenter, C. H. O'Dell, G. P. DiLisio, 
R. G. Johnson, J. R. Gillison, and N. Rait 
ABSTRACT 
Of the 12 elements analyzed in bulk (undifferentiated) sediments 
collected adjacent to drilling rigs on Georges Bank, only barium was found to 
increase in concentration during the period when eight exploratory wells were 
drilled on Georges Bank (July 1981 until September 1982). The maximum 
postdrilling concentration of barium (a major element in drilling mud) reached 
172 ppm in bulk sediments near the drill site in block 410. This 
concentration is higher than the predrilling concentration at this location by 
a factor of 5.9. This maximum barium concentration is within the range of 
predrilling concentrations (28-300 pm) measured in various sediment types from 
the regional stations of this program. No drilling-related changes in the 
concentrations of the 11 other metals have been observed in bulk sediments at 
any of the locations sampled in this program. 
We estimate that about 25 percent of the barite discharged at block 312 
was present in the sediments within 6 km of the rig, four weeks after drilling 
was completed at this location (drilling period: December 8, 1981-June 21.5 
1982). For almost a year following completion of this well, the inventory of 
