70 water samples. Dissolved gold discriminated from particulate gold by filtration through a 1.2-mu filter. The particulate gold concentrations showed excessive scatter, which made their use for locating gold anomalies unpromising. Dissolved gold occurred in concentrations ranging from < or =0.3 to 2.5 parts per trillion to as high as 130 parts per trillion. The limit of detection of the analytic method was 0.3 parts per trillon.--Modified journal abstract.