I 

 z 



Figure 5. NH 4 + versus Si relationships for water samples 



collected at Pele's Vent. The upper figure presents the 

 data collected during the Alvin dive expedition. the middle 

 figure presents the data collected during the Pisces V dive 

 expedition. The bottom figure is the combined data base. 

 The linear regression analyses were: NH4 + = -0.37 + 



0.0065Si ( Alvin ); NH 4 " 



-0.21 + 0.0030 Si (Pisces V). 



204 



